Idea 06 of 06Borrowed from membrane engineering: liquid-gated membranes

A pore-held silicone gel gives a soft web its barrier

Borrowing liquid-gated membranes from membrane engineering, we fill the pore necks of a soft, coarse fibre web with a silicone gel that blocks fluid without a film.

Wide painterly scene. On the left a laboratory bench holds a clear sealed flow cell with a membrane disc and a column of water pressing down on it. The bench surface continues to the right, where an unworn absorbent product lies with one end cut open, showing a soft core above a thin fibre outer cover. Two circular insets along the bottom show matching close-ups: on the left, membrane pores filled with gold liquid holding back blue water at thin red curved surfaces; on the right, open fibres with gold gel in the gaps between them holding back blue fluid at the same thin red curved surfaces. — Fig. 1A liquid-gated membrane in its sealed test cell and a soft absorbent product share one principle: a liquid held in open pores, pinned at each opening, blocks fluid where the bare pores would leak.

What is this idea, and what's clever about it?

In a film-free web, each way of raising the liquid barrier also stiffens the web and makes it rustle: finer fibres, denser packing, more bonding, heavier chemical finish. A liquid-gated membrane, a porous filter whose pores are filled with a liquid that opens and closes them under pressure, follows the same capillary pressure law the outer-cover requirement is written in. Its barrier comes from the tension of the oil–water surface pinned at each pore neck, so moving the barrier into a retained gel leaves the fibres free to be chosen for softness. The source field also admits that one pore cannot be tuned for both gas and liquid, and here that limit becomes a separate vent zone.

Where we’ve seen this before

Hygiene nonwovens
Topsheets, backsheets and acquisition layers
Through-air-bonded carded (combed-fibre) nonwovens are hygiene's established softness substrate; their softness over spunbond (webs that need a bonding pattern) is credited to having no bonding pattern; lines are sold at 16–80 g/m² (grams per square metre).
The part: Soft through-air-bonded fibre webAir Through Bonding Report - Nonwovens Industry ↗ (opens in a new tab)
Membrane science
Liquid-gated PTFE, PVDF, polypropylene and nylon membranes
A capillary-stabilized liquid works 'as a reversible, reconfigurable gate that fills and seals pores in the closed state', with a distinct critical pressure for each gating liquid, on membranes with 5–20 µm pores.
The part: Liquid held in pores as a pressure gateClient Challenge ↗ (opens in a new tab)
Membrane science
Elastomeric liquid-gated porous membranes
The critical pressure for a liquid scales with the liquid–liquid interfacial tension divided by the effective pore size, and the predicted dependence on pore size 'is in accordance with the experimental results'.
The part: Breakthrough pressure set by tension and neck widthLiquid gating elastomeric porous system with dynamically controllable gas/liquid transport ↗ (opens in a new tab)

Where is it inspired from?

Two panels. Panel 1: a clear sealed flow cell on a bench with a membrane disc across its middle, water above pressed down by a pump, and a magnifier showing the disc's pores filled with liquid. Panel 2: two identical pore cross-sections side by side under the same downward water pressure; the bare pore on the left lets blue water drip through, the pore on the right is filled with gold liquid and a thin red curved surface at its top holds the water back. — Fig. 2A liquid-gated membrane clamped in a sealed cell, and its working principle: identical open pores under identical water pressure leak when bare and hold when filled with a liquid pinned at each pore mouth.

A liquid-gated membrane is a porous filter whose pores are filled with a liquid that opens and closes them under pressure 1 2. It has two parts: a porous solid that sets pore size and gives support, and a filling liquid that wets that solid more strongly than the fluid to be passed and does not mix with it 2 3. Capillary forces hold the liquid's surface at each pore mouth, so a solid full of open holes stays sealed 1.

Below a threshold pressure the pore stays shut. Above it, the liquid parts into a lining on the pore wall, the passing fluid touches only liquid, and the pore reseals when the pressure drops 1. The threshold equals four times the interfacial tension divided by the pore width, so chemistry and pore size tune it separately 1 3. Oil held in 5 µm pores gave a threshold of 0.33 bar 4. Known limits: one study found only about 57% of pores open 5, and weak solid–liquid affinity loses liquid during use 6.

How does it transfer?

A layer of porous material can hold back a fluid with a liquid kept in its pores, which the fluid cannot mix with. The pressure that layer holds is four times the tension between the two liquids divided by the width of the narrowest pore opening, so the solid only has to supply the pore shape and a surface the retained liquid wets.

Porous membrane of PTFE, PVDF or nylon→Soft, lightly bonded fibre web of 12 µm fibres
Gating liquid filling every pore→Gating gel: thickened silicone oil with white pigment
Liquid surface pinned at each pore mouth→Pinned oil–water surface at each pore neck
Laplace threshold set by tension over pore size→Breakthrough pressure of about 62 mbar at 16 µm pore necks
Pore reseals at rest after opening→Self-resealing of pore necks after a gush
Pore size and chemistry cannot tune gas and liquid together→Separate gel-free vent zone for air and vapour

What does not carry over

In one liquid-gated membrane, oil held in a 5 µm filter withstood 0.33 bar; the design keeps the fibre web's pore necks at 16 µm, so it stays soft and open, and accepts a breakthrough pressure near 62 mbar.
The source studies mostly use fluorinated oils such as Krytox, though silicone oil appears too; the design thickens a fluorine-free silicone oil into a gel with fumed silica and loads it with white pigment, which also masks the stain.
In the membranes, one pore size and one surface chemistry serve both gas and liquid, and the literature itself records that the two cannot be tuned together; the design splits the two jobs by area, keeping the gated fibre web for fluid and a few percent of the face as an oil-repelling vent zone for air and vapour.

How does it work?

The design is an outer cover made from a soft, lightly bonded fibre web whose narrowest pore openings are filled with a pigmented silicone gel. The gel blocks body fluids up to a set pressure and closes again after a surge, while a small gel-free patch lets air through.

Build a coarse fibre web for softness
The base is a fibre web of 12 µm plastic fibres, fused by hot air only where fibres cross, with no flattening between rollers. This through-air bonding is how the hygiene field already makes its softest webs 7. By design, the widest connected pore neck is 16 µm, checked by capillary-flow porometry. Without gel, this web holds only 15–25 mbar.
Draw the gating gel into pore necks
A fluorine-free silicone oil, thickened with fumed silica and carrying white titanium dioxide, goes on at 7–12 g/m². The oil-attracting fibre surface draws this gating gel by capillary suction into the finest pore necks, leaving a thin gel film on the fibres 1. This holds only if the gel wets the fibres more readily than the fluid does 8. Titanium dioxide bends light far more strongly than the oil, so the gel scatters light 9, which is meant to hide stains; no masking result has been measured.
Hold fluid at a pinned surface
Fluid that reaches a gated pore neck meets a pinned oil–water surface. It gets through only above the breakthrough pressure, which rises with the oil–water interfacial tension and falls as the neck widens. Experiments have confirmed this relation 3. At an assumed 25 mN/m, the projected value is 62.5 mbar against the 62 mbar requirement, with no margin, and the tension against real menses has not been measured. Once the pressure drops, gel flows back from the fibre film and closes the neck again (self-resealing) 1.
Vent air through a separate patch
Air and vapour use a separate vent zone, 2–5 % of the face, since any pore holding 62 mbar of fluid also blocks air. Its pores are finer than 6 µm, as in a granted construction 10. Its finish is meant to keep gel out, but a fluorine-free finish cannot repel this silicone oil, so exclusion depends on the fine pores and the gel dose. At 3 % area, projected airflow is 4.07 cfm (cubic feet of air per square foot per minute), below the 5 cfm floor, so the zone must grow.

Four numbered cross-section panels of the proposed outer cover, core side at the top and outside at the bottom. Panel 1: loosely spaced round fibres joined at a few bond points, with wide gaps. Panel 2: the same fibres with gold gel filling the gaps and thinly coating each fibre, white pigment specks in the gel, and a separate gel-free patch of fine sage fibres at one side. Panel 3: blue fluid from the core above is held at thin red curved surfaces in each gap, while air curls pass through the gel-free patch. Panel 4: on the left, a gap opened with gel lining its walls and fluid passing; on the right, the gap closed again by gel flowing back. — Fig. 3The proposed outer cover in four steps: an open, soft fibre web; gel drawn into its pore necks; fluid held at pinned oil–water surfaces while air uses a separate vent zone; opening above breakthrough pressure and self-resealing at rest.

Why do we think it will work?

The parts of this idea that already work somewhere, and how each carries over here.

Part of the idea	Where it already works	Here
	Hygiene nonwovens · Topsheets, backsheets and acquisition layers Through-air-bonded carded (combed-fibre) nonwovens are hygiene's established softness substrate; their softness over spunbond (webs that need a bonding pattern) is credited to having no bonding pattern; lines are sold at 16–80 g/m² (grams per square metre). 7 11 What is the evidence it will work? Soft through-air-bonded fibre web Where it works Hygiene nonwovens · Topsheets, backsheets and acquisition layers What it does there Through-air-bonded carded (combed-fibre) nonwovens are hygiene's established softness substrate; their softness over spunbond (webs that need a bonding pattern) is credited to having no bonding pattern; lines are sold at 16–80 g/m² (grams per square metre). Here Carries over if: A web of this construction can be formed with pore necks near 16 µm in the gated zone and still stay under 50 g in the cup-crush test (the force needed to crush a cup-shaped sample, a standard measure of fabric stiffness) once loaded with gel. The evidence Air Through Bonding Report - Nonwovens Industry ↗Web page · nonwovens-industry.com “The fact that spunbond requires bonding patterns while ATB does not, is one of the reasons for such a superior performance in softness of ATB versus spunbond ... ATB carded nonwovens are mainly used as a topsheet and backsheet for high-tier products” Andritz - Air-through-bonding overview ↗Web page · andritz.com “It must bind the still fragile and sensitive carded web smoothly into a stable nonwoven product - without reducing its high-lofted character and superior softness.”	Carries over ifA web of this construction can be formed with pore necks near 16 µm in the gated zone and still stay under 50 g in the cup-crush test (the force needed to crush a cup-shaped sample, a standard measure of fabric stiffness) once loaded with gel.
	Membrane science · Liquid-gated PTFE, PVDF, polypropylene and nylon membranes A capillary-stabilized liquid works 'as a reversible, reconfigurable gate that fills and seals pores in the closed state', with a distinct critical pressure for each gating liquid, on membranes with 5–20 µm pores. 1 12 What is the evidence it will work? Liquid held in pores as a pressure gate Where it works Membrane science · Liquid-gated PTFE, PVDF, polypropylene and nylon membranes What it does there A capillary-stabilized liquid works 'as a reversible, reconfigurable gate that fills and seals pores in the closed state', with a distinct critical pressure for each gating liquid, on membranes with 5–20 µm pores. Here Carries over if: The pigmented, silica-thickened gating gel seals the pore necks of a soft fibre web against urine, menses and stool as a gating liquid does in a rigid membrane. The evidence Client Challenge ↗Paper · nature.com “a capillary-stabilized liquid as a reversible, reconfigurable gate that fills and seals pores in the closed state” Fluid-based gating mechanism with tunable multiphase selectivity and antifouling behavior ↗Patent · US 10,330,218 B2 · 2016 · Google Patents “A gating mechanism that uses a capillary stabilized liquid as a reversible, reconfigurable gate that fills and seals pores in the closed state... the gating threshold can be rationally tuned over a wide pressure range.”	Carries over ifThe pigmented, silica-thickened gating gel seals the pore necks of a soft fibre web against urine, menses and stool as a gating liquid does in a rigid membrane.
	Membrane science · Elastomeric liquid-gated porous membranes The critical pressure for a liquid scales with the liquid–liquid interfacial tension divided by the effective pore size, and the predicted dependence on pore size 'is in accordance with the experimental results'. 3 What is the evidence it will work? Breakthrough pressure set by tension and neck width Where it works Membrane science · Elastomeric liquid-gated porous membranes What it does there The critical pressure for a liquid scales with the liquid–liquid interfacial tension divided by the effective pore size, and the predicted dependence on pore size 'is in accordance with the experimental results'. Here Carries over if: The relation, derived for circular pores, also holds for the irregular pore necks of a carded fibre web. The evidence Liquid gating elastomeric porous system with dynamically controllable gas/liquid transport ↗Paper · Sheng et al. · 2018 · doi.org “For a liquid, the critical pressure will be related to the liquid-liquid interfacial tension γ_ll and also the effective pore size d, that is, 4γ_ll/d”	Carries over ifThe relation, derived for circular pores, also holds for the irregular pore necks of a carded fibre web.Tested in What we’d test →
	Membrane science · Liquid-gated membranes The pores 'rapidly and repeatedly open and close in response to pressure', and the liquid lining keeps the transported fluid out of contact with the solid. 12 1 What is the evidence it will work? Self-resealing of the gate after opening Where it works Membrane science · Liquid-gated membranes What it does there The pores 'rapidly and repeatedly open and close in response to pressure', and the liquid lining keeps the transported fluid out of contact with the solid. Here Carries over if: The seal re-forms after a pressure surge in a low-density web whose pore necks move under body compression and shear. The evidence Fluid-based gating mechanism with tunable multiphase selectivity and antifouling behavior ↗Patent · US 10,330,218 B2 · 2016 · Google Patents “A gating mechanism that uses a capillary stabilized liquid as a reversible, reconfigurable gate that fills and seals pores in the closed state... the gating threshold can be rationally tuned over a wide pressure range.” Client Challenge ↗Paper · nature.com “a capillary-stabilized liquid as a reversible, reconfigurable gate that fills and seals pores in the closed state” Fluid-based gating mechanism with tunable multiphase selectivity and antifouling behavior ↗Patent · US 10,330,218 B2 · 2016 · Google Patents “A gating mechanism that uses a capillary stabilized liquid as a reversible, reconfigurable gate that fills and seals pores in the closed state... the gating threshold can be rationally tuned over a wide pressure range.”	Carries over ifThe seal re-forms after a pressure surge in a low-density web whose pore necks move under body compression and shear.Tested in What we’d test →
	Polymer physical chemistry · Cross-linked silicone films Cross-linked silicone is simultaneously water-repellent and highly permeable to water vapour, transmitting it at rates up to 60% of the rate through air. 13 What is the evidence it will work? Silicone as a water-repellent vapour path Where it works Polymer physical chemistry · Cross-linked silicone films What it does there Cross-linked silicone is simultaneously water-repellent and highly permeable to water vapour, transmitting it at rates up to 60% of the rate through air. Here Carries over if: The behaviour measured on unfilled, silica-free silicone films carries over to the thin pigmented, thickened gating gel in the web. The evidence Rediscovering Silicones: The Anomalous Water Permeability of "Hydrophobic" PDMS Suggests Nanostructure and Applications in Water Purification and Anti-Icing. ↗Paper · Bian et al. · 2020 · doi.org “Cross-linked polydimethylsiloxane (PDMS) is simultaneously water-repellent and highly permeable to water vapor ... vapor transmission rates as high as 60% of the transmission rates through air are measured”	Carries over ifThe behaviour measured on unfilled, silica-free silicone films carries over to the thin pigmented, thickened gating gel in the web.
	Interfacial science · Contour-method tensiometry of oil and water The clean interfacial tension between a 1000 cSt silicone oil and water was measured at 37 ± 1.2 mN/m. 14 What is the evidence it will work? Silicone oil–water interfacial tension above design floor Where it works Interfacial science · Contour-method tensiometry of oil and water What it does there The clean interfacial tension between a 1000 cSt silicone oil and water was measured at 37 ± 1.2 mN/m. Here Carries over if: Substances from urine, menses and stool that adsorb at the gel surface lower the tension no further than the 25 mN/m design floor. The evidence Interfacial tension between oil and water measured with a modified contour method ↗Paper · Peters & Arabali · 2013 · doi.org “The calculated interfacial tension of 37 ± 1.2 mN/m, for silicone oil (PDMS, 1000 cS)”	Carries over ifSubstances from urine, menses and stool that adsorb at the gel surface lower the tension no further than the 25 mN/m design floor.Tested in What we’d test →
	Paints and coatings · Hiding power of white paints Light scattering, and so contrast-ratio opacity, is set by the refractive-index difference at the pigment's interfaces with binder and air, and opacity rises with pigment loading. 9 What is the evidence it will work? High-index pigment in a binder for opacity Where it works Paints and coatings · Hiding power of white paints What it does there Light scattering, and so contrast-ratio opacity, is set by the refractive-index difference at the pigment's interfaces with binder and air, and opacity rises with pigment loading. Here Carries over if: A gel film under 1 µm thick, with pigment particles spaced wider apart than the film is thick, still scatters enough light to mask stains. The evidence Hiding power of paints ↗Web page · specialchem.com “The more the difference in refractive index for materials at the interface, the more the light scattering. For example, the air has a refractive index of 1.0, most resins about 1.5-1.6... Opacity = Rb/Rw x 100.”	Carries over ifA gel film under 1 µm thick, with pigment particles spaced wider apart than the film is thick, still scatters enough light to mask stains.
	Textile and nonwoven finishing · Foam application of finishing chemistry Foam applicators give 'exact, uniform application of chemicals at wet pickup levels as low as 5%' (wet pickup: liquid added as a percentage of the fabric's own mass), controlled by linking the treatment liquid's flow rate to line speed. 15 16 What is the evidence it will work? Controlled low-pickup liquid dosing of moving webs Where it works Textile and nonwoven finishing · Foam application of finishing chemistry What it does there Foam applicators give 'exact, uniform application of chemicals at wet pickup levels as low as 5%' (wet pickup: liquid added as a percentage of the fabric's own mass), controlled by linking the treatment liquid's flow rate to line speed. Here Carries over if: The dosing routes the gel into the gated pore necks by capillarity while leaving the pores of the vent zone free of gel. The evidence Applications – Gaston Systems ↗Web page · gastonsystems.com “Exact, uniform application of chemicals at wet pickup levels as low as 5% and speeds beyond 900 meters /min… different chemistry can be applied simultaneously with multiple applicators.” Foam Applications on Textiles — Cotton Incorporated TRI-4009 ↗Web page · cottoninc.com “For cotton-rich fabrics, the wet pickup in foam finishing is typically between 15% and 35%… closed distribution… allows control of wet pickup by linking liquor flow rate to range speed.”	Carries over ifThe dosing routes the gel into the gated pore necks by capillarity while leaving the pores of the vent zone free of gel.

What's different?

Liquid gating, patented broadly for porous membranes, moves into a hygiene outercover: a gating gel pinned in a coarse fibre web's pore necks holds the barrier, beside a gel-free vent zone.

	How it’s done today	This idea
Barrier source	Fine, densely packed fibres plus a low-surface-energy finish	Pinned oil–water surface of a gating gel at each pore neck
Fibre web	Stacked meltblown fine-fibre plies between spunbond skins, tightly bonded	Coarse 12 µm bicomponent fibres at 8–12 % bond area
Stain masking	Basis weight, pigment in fibres, or a separate masking layer	White pigment carried in the same gel that blocks fluid
Air and vapour	The same fibre network carries barrier and breathability	A separate gel-free vent zone, a few percent of the face
Tuning per fluid	Shrink pores, add plies, or change the fibre finish	Retune one interfacial tension between gel and incoming fluid
Key limitation	Barrier, stiffness, opacity and cost move on shared solid quantities	Calculated material cost €0.083–0.208/m² exceeds €0.07/m²; vent airflow 4.07 below 5 cfm

Closest existing work · 4

Kimberly-Clark US-5447788 liquid-activated nonwoven barrier17That web seals when its fibres swell on contact; it has no pinned oil–water surface, so no per-fluid threshold set by interfacial tension over pore-neck width.Google Patents ↗
Harvard US-20180023728 fluid-based gating patent application12Claims liquid gating across pore structures generally; what this design adds is the outercover build: coarse bicomponent fibre web, separate vent zone, pigment in the gel.Google Patents ↗
AVINTIV/Berry WO-2025/059061 film-free breathable backsheet18Same product and problem, but barrier comes from fine-fibre ply count and a non-fluorinated coating, the solid quantities this design moves away from.Google Patents ↗
Oil-gated biphasic nanofibre wound dressing, 202619Also gates with a retained oil, but in concave nanofibre structures for exudate transport, with no vent zone, opacity element or softness constraint.doi.org ↗

What would we test?

The riskiest open question

The gating gel keeps an oil–water interfacial tension of at least 25 mN/m against urine, menses and stool after 30 minutes of contact.

Why it matters: At a 16 µm pore neck, 25 mN/m gives only 62.5 mbar against the 62 mbar requirement, and proteins, bile salts and phospholipids are documented to lower the tension within minutes.
First test: Breakthrough pressure in 2 mbar steps on gated and finish-only webs against five fluids, plus gel tension read from a hanging drop's shape at 1, 10, 30 minutes. 25 26
Go if: Gated web holds at least 62 mbar on all five fluids; tension stays at or above 25 mN/m.
No-go if: Gated breakthrough below 40 mbar on any body fluid, or tension at or below 12 mN/m after 30 minutes.
Effort: $8K–12K · 3 to 5 weeks

The other open questions · riskiest first

The gating gel, not the fibre web itself, sets the breakthrough pressure, which follows interfacial tension divided by pore-neck width.
Why it matters
If the web without gel already holds 40 to 60 mbar, an ordinary hydrophobic coarse web has done the job and the gel adds nothing.
First test
Webs with 8, 16 and 32 µm pore necks, each tested with and without gel, using three silicones of about 40, 25 and 10 mN/m tension. 30 25
Go if
At 16 µm and 25 mN/m, at least 62 mbar and three times the ungated web; pressure tracks tension over neck width.
No-go if
Ungated web already holds 45 mbar or more, or pressure stays flat across the tension series.
Effort
$12K–20K · 4 to 8 weeks
The gel-free vent zone resists a 51.5 mN/m fluid better than the gated area does, so the vent never sets the barrier.
Why it matters
A fluorine-free finish of 19–24 mJ/m² is wetted by a ~50 mN/m fluid, so the vent pores could be the weakest path and set the whole web's breakthrough.
First test
Breakthrough pressure on vent-only, gated-only and assembled coupons with 2 and 8 µm vent pores, against a 51.5 mN/m menses simulant. 30 35
Go if
Assembled web holds at least 70 mbar, within 10 % of gated-only, unchanged between vent pore sizes.
No-go if
Assembled web below 62 mbar, or its value falls with vent pore size like the vent-only value.
Effort
$7K–11K · 3 to 5 weeks
A vent zone of at most 5 % area passes over 5 cfm (cubic feet per square foot per minute) without lowering breakthrough pressure.
Why it matters
A fully gated web passes essentially no air, and at a 3 % vent area the design's own patch permeability gives only 4.07 cfm.
First test
Gated webs with gel-free vent windows at 0 to 25 % area: air permeability, vapour transmission, and breakthrough pressure read cell by cell across the face. 38 39
Go if
At least 5 cfm and 2000 g/m²/day at 5 % vent area; first breakthrough stays in the gated area.
No-go if
Air permeability never reaches 5 cfm below 10 % vent area, or local breakthrough drops 30 % at 5 %.
Effort
$10K–16K · 4 to 6 weeks
The gel stays in the web and holds 62 mbar through converting, warm wear and storage, and the gate reseals after a pressure surge.
Why it matters
Lubricant loss is the recognised failure of every liquid-infused system, and one drained pore neck becomes a pinhole that sets the barrier.
First test
Fluorescent and weighed gel mapping plus breakthrough re-tests after a shear pass, 100 wet compression cycles at 37 °C and 4 weeks at 40 °C. 37 40
Go if
At least 62 mbar on saline and 50 on menses simulant; 70 % gel retained; no migration detected.
No-go if
Below 50 mbar after the sequence, over 40 % of gel lost, or gel found in adjacent layers.
Effort
$10K–16K · 6 to 10 weeks

Also to check before scale-up

Written scope ruling on whether a retained liquid sealing the pore necks counts as a continuous film.
Stain masking at the pigment actually delivered: 4–6 wt % of the gel gives 0.28–0.48 g/m², not 0.6–1.4.
Cup crush (force to crush a cupped sample, a softness test) stays under 50 g with gel in place.
Delivered cost: the cheapest inputs give €0.0845/m² against the €0.07/m² ceiling; which cost clause governs.
Skin-contact safety: cytotoxicity and sensitisation screening of the gel and its extractables.
A fixed per-fluid test protocol: simulant recipes, restraint, fine pressure steps and an exact 62 mbar hold.
Two-stage dosing keeps at least 95 % of the gel in gated zones and under 5 % of vent pores filled.
Trial rolls reach pore necks of 16 µm or less with tensile strength above 19.61 N.
Finished-web vapour transmission above 2000 g/m²/day; the noise attribute has no standard method to score it.

Who could help make this happen?

First contacts

Xu Hou44Xiamen UniversityTo check that the gating gel, not the fibre web, sets the breakthrough pressure, his group already designs the pressure at which fluid crosses a liquid-gated membrane from the liquid's interfacial tension and the pore size.Helps settle: The gating gel, not the fibre web itself, sets the breakthrough pressure, which follows interfacial tension divided by pore-neck width.Full entry in Researchers & labs
Stefano Guido46University of Naples Federico IITo check that the gel's interfacial tension survives real body fluids, work he co-authored has already characterized how real menstrual fluid flows.Helps settle: The gating gel keeps an oil–water interfacial tension of at least 25 mN/m against urine, menses and stool after 30 minutes of contact.Full entry in Researchers & labs
Fibertex Nonwovens AS36Potential partnerTo check that the gel-free vent zone never sets the barrier, it has already developed a fluorine-free silica finish that makes a nonwoven repel oil, the kind of finish the vent zone needs.Helps settle: The gel-free vent zone resists a 51.5 mN/m fluid better than the gated area does, so the vent never sets the barrier.Full entry in Companies
Rob G.H. Lammertink45University of TwenteTo check that the gel stays in the web and reseals after a pressure surge, his group already measures how much infused liquid stays in a liquid-infused membrane after water forces its way through.Helps settle: The gel stays in the web and holds 62 mbar through converting, warm wear and storage, and the gate reseals after a pressure surge.Full entry in Researchers & labs

References

109 sources51 cited in this idea, 58 background reading

Where it comes from7

Where it comes from

The work in the source field that the idea borrows its principle from.

1Paper: Client Challenge
a capillary-stabilized liquid as a reversible, reconfigurable gate that fills and seals pores in the closed state
Why it’s hereThe founding liquid-gated membrane: a pore-held liquid acts as a reversible, pressure-opened gate.
Cited in
Where it comes from How it works Why we believe it
Open source (opens in a new tab)
2Paper: Design of Porous Membranes by Liquid Gating Technology, Wang et al.2021
S. Wang, Y. Zhang, Y. Han and 3 more
utilizes the capillary-stabilized functional liquid as a pressure-driven, reversible, and reconfigurable gate to fill and seal the pores on demand... the two essential parts of the composite membranes: the solid porous matrix and the gating liquid.
Why it’s hereReviews liquid-gated membranes as two parts, porous solid plus gating liquid, opened by pressure.
Cited in
Where it comes from
Open source (opens in a new tab)
3Paper: Liquid gating elastomeric porous system with dynamically controllable gas/liquid transport, Sheng et al.2018
Z. Sheng, H. Wang, Y. Tang and 5 moreScience Advances
For a liquid, the critical pressure will be related to the liquid-liquid interfacial tension γ_ll and also the effective pore size d, that is, 4γ_ll/d
Why it’s hereGives the breakthrough pressure as four times interfacial tension over pore size, checked against experiment.
Cited in
Where it comes from How it works Why we believe it
Open source (opens in a new tab)PDF
4Web page: Separation and Puri昀椀cation Technology Fouling Resistant Liquid-Infused membranes for oil separations, par.nsf.gov
upon applying a threshold pressure of 0.33 bar, Hou et al. demonstrated that oil could be stabilized within filters with a pore size 5.0 µm... the pressure needed for liquid to permeate... was influenced by the pore size, geometry, composition of the base membrane, and the surface tension of the lubricating liquid.
Why it’s hereRecounts oil stabilised in 5.0 µm pores at a 0.33 bar threshold pressure; threshold set by pore and liquid properties.
Cited in
Where it comes from
Open source (opens in a new tab)
5Paper: Research Update: Liquid gated membrane filtration performance with inorganic particle suspensions, Alvarenga et al.2018
J. Alvarenga, Y. Ainge, C. Williams and 4 moreAPL Materials
nearly 57% of LGM pores were open for transport... up to 60% passive flux recovery of LGMs in the presence of whey protein fouling.
Why it’s hereReports about 57% of gated pores open in flow and up to 60% flux recovery under fouling.
Cited in
Where it comes from
Open source (opens in a new tab)PDF
6Paper: Temperature-Regulation Liquid Gating Membrane with Controllable Gas/Liquid Separation, Chen et al.2023
B. Chen, H. Wang, J. Xu and 3 moreGreen Energy & Environment
The weak interaction would lead to the loss of gating liquids when transferring fluids and inevitably affect the stability of the liquid gating system.
Why it’s hereWarns weak liquid–solid interaction causes gating liquid loss during flow.
Cited in
Where it comes from
Open source (opens in a new tab)PDF
8Paper: Bioinspired Design and Applications of Liquid Gating Gas Valve Membranes, Li et al.2025
Y. Li, Y. Liu, R. Xu and 2 moreBiomimetics
liquid gating membranes have been developed utilizing capillary-stabilized liquids to achieve precise fluid regulation... challenges related to precise controllability, long-term stability, and scalable production persist.
Why it’s hereReviews gas-valve liquid gating; notes stability and scalable production remain open challenges.
Cited in
How it works
Open source (opens in a new tab)PDF

Evidence it works10

Evidence it works

Each shows a part of the idea already working somewhere.

9Web page: Hiding power of paints, specialchem.com
The more the difference in refractive index for materials at the interface, the more the light scattering. For example, the air has a refractive index of 1.0, most resins about 1.5-1.6... Opacity = Rb/Rw x 100.
Why it’s hereExplains hiding power from refractive-index contrast and defines contrast-ratio opacity.
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11Web page: Andritz - Air-through-bonding overview, andritz.com
It must bind the still fragile and sensitive carded web smoothly into a stable nonwoven product - without reducing its high-lofted character and superior softness.
Why it’s hereThrough-air bonding fixes carded webs while keeping loft and softness.
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13Paper: Rediscovering Silicones: The Anomalous Water Permeability of "Hydrophobic" PDMS Suggests Nanostructure and Applications in Water Purification and Anti-Icing., Bian et al.2020
P. Bian, Y. Wang and T. J. McCarthyMacromolecular rapid communications
Cross-linked polydimethylsiloxane (PDMS) is simultaneously water-repellent and highly permeable to water vapor ... vapor transmission rates as high as 60% of the transmission rates through air are measured
Why it’s hereMeasured crosslinked silicone transmitting water vapour at up to 60% of the rate through air.
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14Paper: Interfacial tension between oil and water measured with a modified contour method, Peters & Arabali2013
F. Peters and D. Arabali
The calculated interfacial tension of 37 ± 1.2 mN/m, for silicone oil (PDMS, 1000 cS)
Why it’s hereMeasured silicone oil–water interfacial tension of 37 mN/m, above the design's 25 mN/m floor.
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27Paper: PROTEIN FILMS AT OIL-WATER INTERFACES: INTERFACIAL TENSION MEASUREMENTS BY THE STATIC DROP METHOD, Jaynes & Flood1985
E. N. Jaynes and M. A. Flood
Both proteins substantially lowered interfacial tension within the first minute …
Why it’s hereShows proteins lower oil–water interfacial tension within a minute, a risk to the per-fluid barrier.
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28Paper: The bile salt/phospholipid ratio determines the extent of in vitro intestinal lipolysis of triglycerides: Interfacial and emulsion studies., Kłosowska et al.2024
K. Kłosowska, T. d. Castillo-Santaella, J. Maldonado-Valderrama and 1 moreFood Research International
BSs and PLs synergistically enhanced interfacial activity, substantially reducing oil–water interfacial tension.
Why it’s hereShows bile salts and phospholipids together sharply reduce oil–water interfacial tension, relevant to faecal fluids.
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29Paper: Tetrapodal textured Janus textiles for accessible menstrual health, Sanders et al.2023
S. L. Sanders, L. D. Douglas, T. E. Sill and 5 moreiScience
Wetback was ~8× higher with menses simulant (217 ± 87 mg) than saline (27 ± 7 mg), attributed to the lower surface tension 'decreas[ing] the capillary resistance'.
Why it’s hereMeasured about 8× higher wetback with menses simulant than saline, attributed to lower surface tension.
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36Patent application: Fluorine-free hydrophobic and oleophobic nonwoven, US 2025/0263886 A12023
Fibertex Nonwovens ASInventors: P. BOBET and J. KJELDSEN
PDMS finishes typically [have] a surface energy about 22–24 mN/m ... The surface free energy of the coated fiber surfaces ... is preferably lower than 24 mN/m.
Why it’s hereFluorine-free oil-repelling nonwoven finish below 24 mN/m surface energy, a candidate vent zone treatment.
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41Paper: Lubricant Depletion‐Resistant Slippery Liquid‐Infused Porous Surfaces via Capillary Rise Lubrication of Nanowire Array, Tran et al.2021
H. Tran, Y. Kim, C. Ternon and 3 moreAdvanced Materials Interfaces
The main source of lubricant depletion is the growth of a wetting ridge around a droplet of foreign liquid that removes the infused lubricant from the porous surface.
Why it’s hereIdentifies wetting-ridge growth around foreign droplets as the main route of lubricant loss.
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42Paper: Wetting ridges on slippery liquid-infused porous surfaces, Tran et al.2023
H. Tran, D. Lee and D. RiassettoReports on progress in physics. Physical Society
The lubricant layer, however, is depleted over time, causing degradation of liquid repellency.
Why it’s hereShows the lubricant layer on infused surfaces depletes over time, degrading repellency.
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Today's approaches and closest prior art6

Today's approaches and closest prior art

How the field handles the problem now, and the nearest existing work.

7Web page: Air Through Bonding Report - Nonwovens Industry, nonwovens-industry.com
The fact that spunbond requires bonding patterns while ATB does not, is one of the reasons for such a superior performance in softness of ATB versus spunbond ... ATB carded nonwovens are mainly used as a topsheet and backsheet for high-tier products
Why it’s hereThrough-air-bonded carded webs are the hygiene field's soft topsheet and backsheet substrate.
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10Patent: Composite nanofiber materials and methods for making same, US 7,390,760 B12004
Kimberly Clark Worldwide IncInventors: F. Chen, L. Huang and J. D. Lindsay
The PEO nanofiber coating added about five (5) % additional weight ... coating thickness ... about 50 to about 100 microns.
Why it’s herePatent: fine electrospun fibres on coarse fibres giving pores under 6 µm.
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12Patent: Fluid-based gating mechanism with tunable multiphase selectivity and antifouling behavior, US 10,330,218 B22016
Harvard UniversityInventors: J. Aizenberg, X. HOU, M. Khan and 1 more
A gating mechanism that uses a capillary stabilized liquid as a reversible, reconfigurable gate that fills and seals pores in the closed state... the gating threshold can be rationally tuned over a wide pressure range.
Why it’s hereHarvard gating application describing the reconfigurable seal at each pore under pressure.
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17Patent: Porous, nonwoven liquid-activated barrier, US 5,447,7881994
Kimberly Clark CorpInventors: H. Rhim, E. G. Varona and L. Woon
at least about 50 percent by weight of the fibers ... are prepared from a liquid-swellable polymer which is not significantly soluble in the liquid ... In the presence of liquid, the fibers swell to an extent sufficient to substantially block the passage of liquid through the fibrous nonwoven web ... FIG. 1 is a plot of the pore size distribution ... before and after exposing the barrier to liquid
Why it’s herePrior film-free barrier: nonwoven fibres that swell in liquid to block flow.
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18Patent: Liquid barrier and air-permeable backsheet, WO 20250590612024
Berry Global IncInventors: N. FANG, T. Zhang and Y. Jin
Backsheets having a combination of desirable liquid barrier properties and air permeability are provided. The backsheets include outermost spunbond layers and two or more fine-fiber containing nonwoven layers.
Why it’s hereFilm-free backsheet combining spunbond and fine-fibre layers for barrier with air permeability.
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19Paper: Bioinspired “liquid-solid” biphasic dressing with exudate-gating transport, defense-attack antibacterial activity, and anti-adhesion property for exuding infected wound therapy, Chen et al.2026
Z. Chen, C. Wang, Y. Li and 5 moreBioactive Materials
This dressing integrates a... medical antibacterial oil (guest phase) within a concave nanofiber membrane that mimics the structure of octopus suckers (host phase). This unique architecture enables an exudate-triggered self-adaptive gating mechanism, where the oil-filled concaves act as pressure-deformable gates. High hydrostatic pressure from excess exudate opens the gates for unidirectional transport, while low pressure maintains a closed state.
Why it’s hereWound dressing with oil-filled nanofibre gates that open under exudate pressure, close at low pressure.
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Methods for the tests15

Methods for the tests

The rigs, protocols and measures the first tests borrow.

15Web page: Applications – Gaston Systems, gastonsystems.com
Exact, uniform application of chemicals at wet pickup levels as low as 5% and speeds beyond 900 meters /min… different chemistry can be applied simultaneously with multiple applicators.
Why it’s hereFoam application at wet pickup as low as 5%, for the low-pickup gel pass.
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16Web page: Foam Applications on Textiles — Cotton Incorporated TRI-4009, cottoninc.com
For cotton-rich fabrics, the wet pickup in foam finishing is typically between 15% and 35%… closed distribution… allows control of wet pickup by linking liquor flow rate to range speed.
Why it’s hereFoam finishing with wet pickup controlled by flow rate and line speed.
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25Paper: A study on the measurement conditions for determining liquid entry pressure values of hydrophobic membranes, Pyo et al.2024
M. Pyo, D. Kim, H. Kim and 2 moreChemical Engineering Research and Design
Relatively fast rates of pressure increase can lead to excessive LEP values and their variation. 5-min interval is recommended for the efficiency and reproducibility of LEP measurement.
Why it’s hereShows fast pressure ramps inflate breakthrough readings; recommends 5-minute steps, adopted in the pinned protocol.
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26Paper: Measurement of surface and interfacial tension using pendant drop tensiometry., Berry et al.2015
J. D. Berry, M. Neeson, R. Dagastine and 2 moreJournal of Colloid and Interface Science
Arguably the simplest, most robust, and most versatile of these methods is pendant drop tensiometry.
Why it’s herePendant drop tensiometry, used to measure gel–fluid interfacial tension for each test fluid.
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30Web page: Liquid Entry Pressure (LEP or LEPW), doi.org2015
A theoretical expression, based on Young-Laplace equation, enables the estimation of LEP... where (γ) is the liquid surface tension, (θ) the contact angle between liquid and membrane, and (r) is the pore radius.
Why it’s hereGives the Young-Laplace estimate of breakthrough pressure from surface tension, contact angle and pore radius.
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31Paper: Bioinspired Photo-Responsive Liquid Gating Membrane, Zhang et al.2022
R. Zhang, J. Lei, J. Xu and 4 moreBiomimetics
The critical pressure for gas through the liquid gating membrane … was measured with the self-designed transmembrane pressure measurement device by wet/wet current output differential pressure transmitters.
Why it’s hereSupplies a differential-pressure rig for measuring critical pressure across a liquid-gated membrane.
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32Web page: Standard Test Method for Pore Size Characteristics of Geotextiles by Capillary Flow Test, astm.org
Pore sizes ranging from 1 to 1000 μm.
Why it’s hereCapillary flow test for pore size of fibrous sheets across 1 to 1000 µm.
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33Web page: Standard Test Methods for Pore Size Characteristics of Membrane Filters by Bubble Point and Mean Flow Pore Test, store.astm.org
Test Method A presents a test method for measuring the maximum limiting pore diameter ... The effective pore size calculated from this test method is based on the premise of capillary pores having circular cross sections.
Why it’s hereBubble point method for the largest pore neck, assuming circular capillary pores.
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34Web page: Capillary Flow Porometry (CFP) - Complete Technical Guide, porosimetry.com
d = 4γ cos θ / ΔP... a completely wetted membrane prevents gas flow until sufficient pressure overcomes the capillary forces holding liquid in the pores... CFP determines bubble point (largest pore), mean flow pore size, and complete pore size distribution.
Why it’s hereExplains capillary flow porometry: largest pore, mean flow pore and full pore-size distribution.
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35Paper: Membranes for the Gas/Liquid Phase Separation at Elevated Temperatures: Characterization of the Liquid Entry Pressure, Claramunt et al.2021
S. Claramunt, F. Völker, U. Gerhards and 2 more
The Visual Method and the Pressure Step Method were applied for the experimental investigation. The results show the Pressure Step Method to be an early detection method.
Why it’s hereCompares visual and pressure-step detection of liquid breakthrough; the pressure-step method detects earlier.
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37Paper: Mapping Depletion of Lubricant Films on Antibiofouling Wrinkled Slippery Surfaces., Peppou-Chapman & Neto2018
S. Peppou-Chapman and C. NetoACS Applied Materials and Interfaces
Mapping Depletion of Lubricant Films on Antibiofouling Slippery Liquid-Infused Porous Surfaces
Why it’s hereMaps where lubricant films deplete on liquid-infused surfaces; used to check gel retention after ageing.
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38Web page: Standard Test Method for Air Permeability of Textile Fabrics, astm.org
Standard Test Method for Air Permeability of Textile Fabrics, ASTM Committee D13.
Why it’s hereStandard air permeability test for textile fabrics, used to measure flow through the vent zone.
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39Web page: Standard Test Methods for Gravimetric Determination of Water Vapor Transmission Rate of Materials, astm.org
Agreement is not to be expected between results obtained by different methods … the test conditions employed are at the discretion of the user, but in all cases, are reported with the results.
Why it’s hereGravimetric water vapour transmission standard; conditions must be reported since methods disagree.
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40Paper: Effects of multiple wetting incidents, shear and sliding friction on lubricant stability in SLIPS, Niemelä et al.2023
H. Niemelä, M. Tuominen, H. Koivuluoto and 1 moreCold Regions Science and Technology
We tested the wetting durability and stability of SLIPS with multicycle Wilhelmy plate … we examined the effects of centrifugal and friction-based shear stress to investigate the lubricant depletion from the structure.
Why it’s hereMulticycle wetting and shear tests for lubricant loss, borrowed for gel durability testing.
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43Paper: Fluorescence microscopy visualization of the roughness-induced transition between lubrication regimes, Petrova et al.2019
D. Petrova, B. Weber, C. Allain and 4 moreScience Advances
we introduce a fluorescence microscopy method to dynamically image the lubrication layer in three dimensions.
Why it’s hereFluorescence microscopy imaging the lubricant layer in 3D, for locating the gel in the fibre web.
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People and organizations13

People and organizations

The researchers, labs, companies and suppliers who could help make the idea happen.

44Web page: Liquid gating membrane, academic.oup.com
The trade-offs between surface chemistry and size requirements make it difficult to differentially tune the behaviors of gases and liquids simultaneously
Why it’s hereNotes solid pore chemistry and size make it hard to tune gas and liquid passage separately.
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45Web page: Liquid-liquid displacement in slippery liquid-infused membranes (SLIMs) - University of Twente Research Information, research.utwente.nl
Skip to main navigation Skip to search Skip to main content [University of Twente Research Information Home University of Twente Research Information Logo](https://research.utwente.nl/en/) Search content at University of Twente Research Information # Liquid-liquid displacement in slippery liquid-infused membranes (SLIMs) * Hanieh Bazyar * , Pengyu Lv * , [Jeffery A. Wood](https://research.utwente.nl/en/persons/jeff-wood/) * , Slawomir Porada * , [Detlef Lohse](https://research.utwente.nl/en/persons/detlef-lohse/) * , [Rob G.H. Lammertink](https://research.utwente.nl/en/persons/rob-lammertink/) \* (Corresponding Author) \* Corresponding author for this work * [Soft matter, Fluidics and Interfaces](https://research.utwente.nl/en/organisations/soft-matter-fluidics-and-interfaces/) * [Physics of Fluids](https://research.utwente.nl/en/organisations/physics-of-fluids/) Research output : Contribution to journal › Article › Academic › peer-review [41 Link opens in a new tab](https://www.scopus.com/pages/publications/85043362719=citedBy) Citations (Scopus) 309 Downloads (Pure) [](https://plu.mx/plum/a/?doi=10.1039/c7sm02337e) * [Overview](https://research.utwente.nl/en/publications/liquid-liquid-displacement-in-slippery-liquid-infused-membranes-s/) * [Fingerprint](https://research.utwente.nl/en/publications/liquid-liquid-displacement-in-slippery-liquid-infused-membranes-s/fingerprints/) * [Datasets (1)](https://research.utwente.nl/en/publications/liquid-liquid-displacement-in-slippery-liquid-infused-membranes-s/datasets/) ## Abstract Liquid-infused membranes inspired by slippery liquid-infused porous surfaces (SLIPS) have been recently introduced to membrane technology. The gating mechanism of these membranes is expected to give rise to anti-fouling properties and multi-phase transport capabilities. However, the long-term retention of the infusion liquid has not yet been explored. ... ## Other files and links * [Link to publication in Scopus](https://www.scopus.com/pages/publications/85043362719) ## Fingerprint Dive into the research topics of 'Liquid-liquid displacement in slippery liquid-infused membranes (SLIMs)'. Together they form a unique fingerprint. * Immiscible Displacement Engineering 100% * Phase Saturation Engineering 100% [View full fingerprint](https://research.utwente.nl/en/publications/liquid-liquid-displacement-in-slippery-liquid-infused-membranes-s/fingerprints/) ## Datasets * ### [Data underlying the publication: Liquid–liquid…
Why it’s hereHis group studied how long liquid-infused membranes keep their infused liquid. They found that water opens pores at their capillary pressure, and that the infused liquid stays behind as pools, bridges and thin films on the pore walls.
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46Web page: Stefano GUIDO | Professor (Full) | PhD | University of Naples Federico II, Naples | UNINA | Department of Chemical, Materials and Industrial Production Engineering | Research profile, researchgate.net
Cariati](https://www.researchgate.net/profile/Federica-Cariati) * [...] * [Stefano Guido Stefano Guido](https://www.researchgate.net/profile/Stefano-Guido-3) Human semen is a complex biological fluid whose rheological properties are relevant to male fertility and assisted reproductive technologies. Standard clinical assessment is largely qualitative and operator dependent, motivating the search for objective biophysical markers of semen quality. Although normospermic semen is commonly assumed to behave... [View](https://www.researchgate.net/publication/404031824_Viscoelastic_alterations_of_human_semen_associated_with_diagnosed_male_infertility) [](https://www.researchgate.net/figure/Simulation-of-blood-flow-in-a-straight-channel-with-a-sinusoidal-bottom-wall-resembling_fig1_403605878) [](https://www.researchgate.net/figure/Spatial-distribution-of-platelet-capture-along-the-sinusoidal-surface-Heatmaps-show-the_fig2_403605878) ... [View](https://www.researchgate.net/publication/401103784_Author_Correction_Defective_CFTR_induces_aggresome_formation_and_lung_inflammation_in_cystic_fibrosis_through_ROS-mediated_autophagy_inhibition) [The Dilemma of Cancer Biomechanics Assessment: Living Soft Matter from a Rheological Perspective](https://www.researchgate.net/publication/400432904_The_Dilemma_of_Cancer_Biomechanics_Assessment_Living_Soft_Matter_from_a_Rheological_Perspective) Article Full-text available * Feb 2026 Materials Today Bio * [Rosalia Ferraro Rosalia Ferraro](https://www.researchgate.net/profile/Rosalia-Ferraro) * [Stefano Guido Stefano Guido](https://www.researchgate.net/profile/Stefano-Guido-3) * [Sergio Caserta Sergio Caserta](https://www.researchgate.net/profile/Sergio-Caserta) ... [Rheological Characterization of Menstrual Fluid. XVIII Italian Society of Rheology Conference.](https://www.researchgate.net/publication/389207704_Rheological_Characterization_of_Menstrual_Fluid_XVIII_Italian_Society_of_Rheology_Conference) Presentation * Sep 2024 * [Jan Claußen Jan Claußen](https://www.researchgate.net/profile/Jan-Claussen-3) * [Christian Neu Christian Neu](https://www.researchgate.net/scientific-contributions/Christian-Neu-2306120629) * [Aexandra Wolf Aexandra Wolf](https://www.researchgate.net/scientific-contributions/Aexandra-Wolf-2306160557) * [...] * [Stefano Guido Stefano Guido](https://www.researchgate.net/profile/Stefano-Guido-3) real menses characterization; femcare prodcuts [View](https://www.researchgate.net/publication/38…
Why it’s hereHe co-authored a rheological characterization of real menstrual fluid.
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47Web page: SLIPS: Slippery Liquid-Infused Porous Surfaces - Wyss Institute, wyss.harvard.edu
SLIPS: Slippery Liquid-Infused Porous Surfaces SLIPS technology, inspired by the Nepenthes pitcher plant, provides unique capabilities that are unmatched by any other liquid-repellent surface technologies. Credit: Wyss Institute at Harvard University. The need for an inexpensive, super-repellent surface cuts across a vast swath of societal sectors—from refrigeration and architecture, to medical devices and consumer products. Most state-of-the-art liquid repellent surfaces designed in the last decade are modeled after lotus leaves, which are extremely hydrophobic due to their rough, waxy surface and the physics of their natural design. However, none of the lotus-inspired materials designed so far has met the mark: they may repel water but they fail to repel oils, fail under physical stress, cannot self-heal – and are expensive to boot. ‘SLIPS’ technology, inspired by the slippery pitcher plant that repels almost every type of liquid and solid, is a unique approach to coating industrial and medical surfaces that is based on nano/microstructured porous material infused with a lubricating fluid. By locking in water and other fluids, SLIPS technology creates slick, exceptionally repellent and robust self-cleaning surfaces on metals, plastics, optics, textiles and ceramics. These slippery surfaces repel almost any fouling challenge a surface may face—whether from bacteria, ice, water, oil, dust, barnacles, or other contaminants. > The versatility of SLIPS, their robustness and unique ability to self-heal makes it possible to design these surfaces for use almost anywhere, even under extreme temperature and pressure conditions. > > Joanna Aizenberg SLIPS: Slippery Liquid-Infused Porous Surfaces SLIPS combines a lubricated film on a porous solid material to create low-cost surfaces that exhibit ultra-liquid repellency, self-healing, optical transparency, pressure stability, and self-cleaning. Credit: Wyss Institute at Harvard University. SLIPS is being commercialized by [Adaptive Surface Technologies](https://adaptivesurface.tech/) (formerly SLIPS Technologies, Inc.), [a company spun out of the Wyss Institute](https://wyss.harvard.edu/news/wyss-institute-launches-slips-company/) , which will provide material coating solutions to multiple industrial, consumer and biomedical markets by creating customized, highly repellent slippery surfaces for a broad range of applications. * Linked in * BlueSky * Facebook ## Publications & Press * [Awards _November 8, 2018_ …
Why it’s hereIt was spun out of the Wyss Institute to bring slippery liquid-infused porous surfaces to market as coatings on plastics, textiles and other materials.
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48Patent: Articles containing nanofibers for use as barriers, US 9,464,369 B22005
Procter and Gamble CoInventors: O. E. A. Isele, R. Chhabra, H. Xu and 2 more
Mean pore diameter of less than about 15 microns… product of the hydrohead and the air permeability divided by the basis weight… greater than about 500 mbar*meter per minute per gsm.
Why it’s hereP&G film-free spunbond/nanofibre barrier scored by hydrohead times air permeability per basis weight.
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49Patent: Breathable absorbent article, US 12,558,273 B22020
Allegiance CorpInventors: W. H. Isaac
hydrostatic pressure of the backsheet may be greater than or equal to 60 centimeters based on AATCC Test Method 127-2008 ... the air permeability of the underpad may range from 5 to 35 cubic feet per minute.
Why it’s hereFilm-free breathable backsheet patent with hydrostatic and air permeability ranges.
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50Web page: Get into care business with air-through bonding — ANDRITZ ATB brochure, andritz.com
The ANDRITZ air-through bonding lines deliver all nonwovens fabric characteristics for hygiene end uses, such as top-sheets and acquisition distribution layers, and back sheets ... from 16 to 80 gsm made from bi-component fibers
Why it’s hereSupplier lines make through-air-bonded bicomponent webs at 16 to 80 gsm for hygiene.
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51Web page: About - Gaston Systems, gastonsystems.com
Gaston Systems Gaston Systems Search: * [About](https://gastonsystems.com/about_gaston/) * [Applications](https://gastonsystems.com/applications/) * [News](https://gastonsystems.com/blog/) * [Contact](https://gastonsystems.com/contact/) # About **ABOUT** Gaston Systems designs and builds advanced coating systems for the textile and nonwoven industries. Using propriety foam generation and application systems, Gaston Systems has an international reputation for offering high quality and innovative technologies to satisfy long-term sustainability requirements. Founded in 1979, Gaston System has more than 500 installations worldwide and an international reputation for high quality and innovative technologies. In 2022 Gaston Systems joined the Navis TubeTex group of brands. ### Chemical Foam Systems **PILOT LINE** In our facilities, we have multiple, configurable pilot lines operated by experienced technologists. Contact us for suitability and application trials. **AFTER SALES & SERVICE AFTER SALES & SERVICE** Gaston Systems provides after sales Service and Spare Parts from our factory warehouse stocked with large inventory of likely spares parts. Additionally our technologists and technicians are available for process and equipment support. Later model units are equipped with network devices for remote troubleshooting and modifications. ## Call our Authorized Agents Providing full parts and service support to our customers. Offering solutions for your chemical application process, upgrades and technical assistance through our customer Support team. Call now to learn more [](https://navisglobal.com/) [](https://tandematic.com/) [](https://consultexsystems.com/) [](http://navisglobal.com/project/stenter/) [Gaston Systems](https://gastonsystems.com/) © Gaston Systems. All rights reserved. \ Go to Top Translate »
Why it’s hereFoam application at low wet pickup, with pilot lines for trials
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52Web page: NWSP 80.6 Water Resistance (Hydrostatic Pressure) » SGS-IPS Testing, ipstesting.com
The rate of increase of the water pressure must be 10 ± 0.5 cm or 60 ± 3 cm H2O/min. Using these two different rates may give different end results. It is important to list in the test results which rate was used.
Why it’s hereHydrostatic head standard allowing two ramp rates that differ; support mesh must be reported.
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53Web page: KRÜSS - Advancing your Surface Science, kruss-scientific.com
KRÜSS - Advancing your Surface Science Machinery Manufacturing As specialists in interfacial chemistry and the world's leading supplier of measuring instruments for surface and interfacial tension, we not only provide high quality product solutions - our offer is a combination of technology and scientific consulting. These include seminars, technical service, and our Applications & Science Center for professional measurement services. Many well-known companies have already been inspired by our know-how, precision and passion consulted by our offices in Hamburg, the USA, China, Great Britain, France and with the help of our exclusive distributor network. Acting quickly and flexibly, we are always at our customer’s doorstep in the research and development laboratories as well as quality control centers of countless industries all over the world.
Why it’s hereInterfacial tension instruments and measurement services
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54Web page: DataPhysics Instruments GmbH, dataphysics-instruments.com
DataPhysics Instruments GmbH is a Appliances, Electrical, and Electronics Manufacturing company. DataPhysics Instruments is a company that provides products for analyzing surfaces and interfaces. They offer contact angle measuring systems, tensiometers, spinning drop tensiometers, and dispersion stability analysis systems. DataPhysics Instruments GmbH employs 27 people (+8.0% YoY, +2 people), founded in 1997. Headquartered in Germany, with presence in United States. Its workforce is distributed across 5 countries (including Germany, France, Spain, United Kingdom, and United States). ... DataPhysics Instruments GmbH is a German company from the Stuttgart region. It has been developing, manufacturing, and distributing laboratory measuring devices for the characterisation of interfaces and surfaces for over 25 years. With 45 employees, and a worldwide distribution network, the company is one of the leading manufacturers of analytical, high-precision systems in this field. In short, the laboratory measuring devices from DataPhysics Instruments are used whenever a liquid meets another liquid or a solid. More precisely, the devices can be used to determine important physical and chemical parameters such as surface tension and surface energy, force of adhesion, static and dynamic contact angles, roughness, zeta potential, and destabilisation mechanisms. ... - contact angle meters of the OCA series - optical measuring systems for determining many parameters of interfaces and surfaces, such as surface tension and energy, interfacial tension, as well as static and dynamic contact angles. - tensiometers of the DCAT series - force-based instruments for investigating a number of interface and surface parameters, such as surface tension and energy, interfacial tension, dynamic contact angle, as well as critical micelle formation concentration and force of adhesion. - SVT 25 spinning drop tensiometer - for characterising extremely low interfacial tensions between two liquids and interfacial rheology. ... analytical instruments, analytics, chemistry, contact angle, contact angle measuring systems, dispersion analysis, dispersion stability analysis systems, dispersions, emulsions, industrial, interfacial science, laboratory, manufacturing, non-destrutive analysis, research, rheology, science_and_education/chemistry, spinning drop tensiometer, surface energy, surface science, surface tension, surfaces, tensiometer, test and measurement, zeta potential # DataPhysics Instruments GmbH DataPhysics Instruments GmbH is a Appliances, Electrical, and Electronics Manufacturing company. DataPhysics Instruments is a company that provides products for analyzing surfaces and interfaces. They offer contact angle measuring systems, tensiometers, spinning drop tensiometers, and dispersion stability analysis systems. DataPhysics Instruments GmbH employs 27 people (+8.0% YoY, +2 people), founded in 1997. Headquartered in Germany, with presence in United States. Its workforce is d…
Why it’s hereOptical drop-shape systems that measure interfacial tension
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55Web page: Porometer, porometer.com
on developing and ... izing instruments to measure pore size distribution, gas and liquid permeability. Our porometers are very much appreciated by both R&D and quality control labs to characterize the pore size and the pore size distribution for media used in filtration and separation processes, such as polymeric and ceramic membranes – including flat sheet and hollow fibre membranes – , non-wovens, paper, porous rocks, etc. The gas-liquid porometers measure through pores in the range of 500 μm to 15 nm, while the liquid-liquid porometers can measure through pores down to 2 nm. Our porometers are built in Germany with some unique designed components to guarantee the most accurate measurement of pressure and flow. Typical applications include dialysis, desalination, battery separators, carbon nanofibers, personal care. Next to porometers, we also develop & manufacture instruments used for membrane synthesis and characterization, such as an automatic membrane/film casting machine (MEMCAST™), or liquid permeability tester. Porometer also offers contract testing. ... capillary flow porometers, electronics, filter & membrane testing equipment, filter characterisation, gas liquid porometry, industrial, liquid liquid porometry, liquid permeability, manufacturing, manufacturing-industrial, measurement instruments, membrane characterisation, membrane synthesis, nonwovens characterisation, pore size, porous materials, products, sample analysis servcie, test and measurement ... 7 · 6 reactions] 𝙃𝙤𝙬 𝙢𝙪𝙘𝙝 𝙙𝙤𝙚𝙨 𝙮𝙤𝙪𝙧 𝙬𝙚𝙩𝙩𝙞𝙣𝙜 𝙡𝙞𝙦𝙪𝙞𝙙 𝙞𝙣𝙛𝙡𝙪𝙚𝙣𝙘𝙚 𝙮𝙤𝙪𝙧 𝙘𝙖𝙥𝙞𝙡𝙡𝙖𝙧𝙮 𝙛𝙡𝙤𝙬 𝙥𝙤𝙧𝙤𝙢𝙚𝙩𝙧𝙮 𝙧𝙚𝙨𝙪𝙡𝙩𝙨? More than you might think. The wetting liquid is a fundamental part of every capillary flow porometry measurement.... # Porometer Porometer is a Appliances, Electrical, and Electronics Manufacturing company. Porometer is a leading manufacturer of instruments for measuring pore size and liquid permeability of porous materials. They offer a wide range of products and services for various applications and industries. Porometer employs 8 people. Headquartered in Berlin, Berlin, Germany, with presence in Belgium, United States, China, and Poland. Its workforce is distributed across Belgium, Poland, China, and Finland. ## About Porometer focuses on developing and commercializing instruments to measure pore size distribution, gas and liquid permeability. Our porometers are very much appreciated by both R&D and quality control labs to characterize the pore size and the pore size distribution for media used in filtration and separation processes, such as polymeric and ceramic membranes – including flat sheet and hollow fibre membranes – , non-wovens, paper, porous rocks, etc. The gas-liquid porometers measure through pores in the range of 500 μm to 15 nm, while the liquid-liquid porometers can measure through pores down to 2 nm. Our porometers are built in Germany with some unique designed components to guarantee the most accurate measurement of pressure and flow. Typical applicati…
Why it’s hereCapillary flow porometers and contract pore-size testing of nonwovens
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56Web page: Textest AG, textest.ch
Textest AG is a Measuring and Control Instrument Manufacturing company. TEXTEST AG is a market leader in testing equipment for air permeability and water tightness. They have been a supplier of testing equipment for the textile, nonwoven, filter, paper, and plastics industries for over six decades. Textest AG employs 7 people, founded in 1964. Headquartered in Schwerzenbach, Zurich, Switzerland. ... TEXTEST AG exists since 1969 and is a Swiss manufacturer of testing instruments for technical textiles. The main focus lies on a comprehensive family of Air Permeability Testers, a Hydrostatic Head Tester, a Water Vapor Transmission Rate Tester, and an on-line instrument for determination of air permeability and thickness at the moving web. The FX 3300 Air Permeability Tester LabAir IV determines the air permeability, the pressure drop and other related parameters under laboratory conditions. It complies with many national and international standard test methods and can be adapted for numerous special applications. The FX 3340 MinAir is a compact and mobile version of the laboratory instrument. The FX 3345 FlexAir is particularly suitable for measuring the air permeability or the pressure drop of contaminated (filter) materials. The FX 3360 PortAir is a portable instrument for profile measurements of air permeability, pressure drop, and thickness in the production or finishing line. The FX 3370 SpotAir can be used to determine the Air Permeability and the Pressure Drop in the moving production line. The same measuring module can be used hand-held, or it can be mounted to the frame of the production or finishing machine for a continuous profile measurement. The FX 3500 CombiScan continuously measures the air permeability or pressure drop, and, optionally, the thickness, and displays length, cross or zigzag profiles. The FX 3000 Hydrostatic Head Tester HydroTester IV is used for automatic determination of the water resistance of any flat material. The FX 3180 Water Vapor Transmission Rate Tester CupMaster automatically determines the WVTR of up to 15 samples simultaneously based on the gravimetric method. The FX 3250 PICK COUNTER automatically determines the thread density of woven and knitted materials up to 300/cm or 762/inch. ... · 2 ... device, the FX 33 ... 0 SpotAir # Textest AG Textest AG is a Measuring and Control Instrument Manufacturing company. TEXTEST AG is a market leader in testing equipment for air permeability and water tightness. They have been a supplier of testing equipment for the textile, nonwoven, filter, paper, and plastics industries for over six decades. Textest AG employs 7 people, founded in 1964. Headquartered in Schwerzenbach, Zurich, Switzerland. ## About TEXTEST AG exists since 1969 and is a Swiss manufacturer of testing instruments for technical textiles. The main focus lies on a comprehensive family of Air Permeability Testers, a Hydrostatic Head Tester, a Water Vapor Transmission Rate Tester, and an o…
Why it’s hereAir permeability, hydrostatic head and vapour transmission testers
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Read while building the idea; not cited in the text.

20Web page: Apertured film/nonwoven composite for personal care absorbent articles and the like - Kimberly-Clark Corporation, freepatentsonline.com
To bond the bicomponent spunbonded web a through-air bonder is used. Such through-air bonders are well known in the art and therefore need not be described. In the through-air bonder, a flow of heated air is applied through the web to heat the web to a temperature above the melting point of the lower melting point component of the bicomponent fibers but below the melting point of the higher melting point component. Upon heating, the lower melting polymer portion of the web fibers are melted and the melted portions of the fibers adhere to adjacent fibers at the cross-over points while the high melting polymer portions of the fibers tend to maintain the physical and dimensional integrity of the web. Bonded carded webs are made from staple fibers which are usually purchased in bales. The bales are placed in a picker which separates the fibers. Next, the fibers are sent through a combing or carding unit which further breaks apart and aligns the staple fibers in the machine direction so as to form a machine direction-oriented fibrous nonwoven web. Once the web has been formed, it is then bonded by one or more of several bonding methods. One bonding method is powder bonding wherein a powdered adhesive is distributed through the web and then activated, usually by heating the web and adhesive with hot air. Another bonding method is pattern bonding wherein heated calendar rolls or ultrasonic bonding equipment is used to bond the fibers together, usually in a localized bond pattern though the web can be bonded across its entire surface if so desired. The best method though, when using bicomponent staple fibers is to use a through-air bonder such as is described above with respect to the bicomponent spunbond web formation process. An important factor in forming the separation layer 26 is that it maintains its lofty nature. ... It had a peripheral seal construction with an apertured film body side liner and no transfer layer. Three commercially available films were selected for use with the present invention. They included the previously described Sultex film from Gruppo Fintex and Partners Italia of Pistoia, Italy, the AET film from Applied Extrusion Technologies of Middleton, Del. and the Mitsui film from Mitsui and Company, Ltd. of Tokyo, Japan. In conjunction with the above mentioned films, a series of fibrous nonwoven web separation layers were prepared and tested. One set of separation layers were made from bicomponent spunbond nonwoven webs while a second set of separation layers were made from through-air bonded carded webs using polyethylene sheath/polypropylene core bicomponent staple fibers. In addition, several standard fibrous nonwoven webs were also prepared including a spunbond and a meltblown web to demonstrate the difference between the materials of the present invention and conventional two layer cover materials. The bicomponent spunbond nonwoven web (Bico SB) was made with 3 denier polyethylene/polypropylene spunbond fibers. The web had a basis weight of 1.2 osy (41 gsm), a bulk of 0.052 inches (1.2 mm) and an average pore size of 140 microns. The through-air bonded carded web (TABCW) had a basis weight of 0.8 osy (27 gsm) and was made from a 50/50 weight percent blend, based upon the total weight of the web, of 51 mm long 1.8 and 3.0 denier polyethylene sheath/polyester core bicomponent staple fibers. The comparative spunbond nonwoven web was made from 5.0 denier polypropylene fibers. It was point bonded using a point bond pattern having a total bond area of 15%. The spunbond web had a basis weight of 0.95 osy (32.3 gsm), a bulk of 0.011 inches
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21Patent: U.S. Patent for Surge management fibrous nonwoven web for personal care absorbent articles and the like Patent (Patent # 5,490,846 issued February 13, 1996) - Justia Patents Search, US 5,490,846
[Justia](https://www.justia.com) Patents Thermoplastic U.S. Patent for Surge management fibrous nonwoven web for personal care absorbent articles and the like Patent (Patent # 5,490,846) # Surge management fibrous nonwoven web for personal care absorbent articles and the like Feb 9, 1995 \- Kimberly-Clark Corporation Disclosed herein is a fibrous nonwoven web which is particularly well-suited for use as a surge layer in personal care absorbent articles including, but not limited to, diapers, training pants, incontinence garments, sanitary napkins, bandages and the like. The fibrous nonwoven web is made from a plurality of fibers heat bonded to one another to form a nonwoven web having a basis weight of at least 20 grams per square meter, a void volume of between about 40 and about 60 centimeters per gram of web while under a pressure of 689 dynes per square centimeter, a permeability of about 5,000 to about 8,000 darcy, a porosity of about 97.2 percent to about ... The drawn and crimped fibers are deposited onto a continuous forming surface in a random manner, generally assisted by a vacuum device placed underneath the forming surface. The purpose of the vacuum is to eliminate the undesirable scattering of the fibers and to guide the fibers onto the forming surface to form a uniform unbonded web of bicomponent fibers. If desired, the resultant web can be lightly compressed by a compression roller before the web is subjected to a bonding process. To bond the bicomponent spunbonded web a through-air bonder is used. Such through-air bonders are well known in the art and therefore need not be described herein in detail. In the through-air bonder, a flow of heated air is applied through the web to heat the web to a temperature above the melting point of the lower melting point component of the bicomponent fibers but below the melting point of the higher melting point component. Upon heating, the lower melting polymer portion of the web fibers are melted and the melted portions of the fibers adhere to adjacent fibers at the cross-over points while the high melting polymer portions of the fibers tend to maintain the physical and dimensional integrity of the web. Bonded carded webs are made from staple fibers which are usually purchased in bales. The bales are placed in a picker which separates the fibers. Next, the fibers are sent through a combing or carding unit which further breaks apart and aligns the staple fibers in the machine direction so as to form a machine direction-oriented fibrous nonwoven web. Once the web has been formed, it is then bonded by one or more of several bonding methods. One bonding method is powder bonding wherein a powdered adhesive is distributed through the web and then activated, usually by heating the web and adhesive with hot air. Another bonding method is pattern bonding wherein heated calendar rolls or ultrasonic bonding equipment are used to bond the fibers together, usually in a localized bond pattern though the web can be bonded across its entire surface if so desired. The best method though, when using bicomponent staple fibers is to use a through-air bonder such as is described above with respect to the bicomponent spunbond web formation process. In order to obtain the specified range of physical properties of the resultant fibrous nonwoven web according to the present invention, the bonding process used to bond the fibers of the fibrous nonwoven web together should be a process such as through-air bonding which can control the level of compression or collapse of the structure during the formation process. In through-air bonding, heated air is forced through the web to melt and bond together the fibers at their crossover points. Typically the unbonded web is supported on a forming wire or drum. ... The resultant fibrous nonwoven web will be a uniformly mixed homogenous single layer blend of whatever type fiber or fibers are chosen. To facilitate the through-air bonding process, it has been found advantageous to use bicomponent fibers which have both a higher melting point and lower melting point component such as in a side-by-side, sheath/core or islands-in-the-sea configurations. The lower melting point component or polymer of the bicomponent fibers provides an efficient means for bonding the fibers together while the higher melting point component aids in maintaining the structural rigidity and the openness of the material both in the dry and wet states. Suitable bicomponent fibers include, for example, whether in staple fiber or more continuous spunbond form, polyethylene/polypropylene and polyethylene/polyester fibers. ... The target basis weight for Examples 1 and 2 was approximately 50 grams per square meter (gsm). The actual basis weights are given in Table 1. All samples were prepared using conventional carding equipment and were subsequently through-air bonded at temperatures and times sufficient to cause the lower melting point component of the bicomponent fibers to at least partially melt and bond to one another at their crossover points. In Example 1, a 50.5 gsm fibrous nonwoven web was created using a homogeneous blend of 60 percent by weight 4.4 denier by 38mm millimeter soft 71 polypropylene fibers from
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22Patent: U.S. Patent for Fibrous nonwoven web surge layer for personal care absorbent articles and the like Patent (Patent # 5,486,166 issued January 23, 1996) - Justia Patents Search, US 5,486,166
[Justia](https://www.justia.com/) [Patents](https://patents.justia.com/) [Thermoplastic](https://patents.justia.com/patents-by-us-classification/604/366) U.S. Patent for Fibrous nonwoven web surge layer for personal care absorbent articles and the like Patent (Patent # 5,486,166) # Fibrous nonwoven web surge layer for personal care absorbent articles and the like Feb 9, 1995 \- [Kimberly-Clark Corporation](https://patents.justia.com/assignee/kimberly-clark-corporation) Disclosed herein is a lofty fibrous nonwoven web which is particularly well-suited for use as a surge layer in personal care absorbent articles including, but not limited to, diapers, training pants, incontinence garments, sanitary napkins, bandages and the like. ... In the through-air bonder, a flow of heated air is applied through the web to heat the web to a temperature above the melting point of the lower melting point component of the bicomponent fibers but below the melting point of the higher melting point component. Upon heating, the lower melting polymer portion of the web fibers are melted and the melted portions of the fibers adhere to adjacent fibers at the cross-over points while the high melting polymer portions of the fibers tend to maintain the physical and dimensional integrity of the web. Bonded carded webs are made from staple fibers which are usually purchased in bales. The bales are placed in a picker which separates the fibers. Next, the fibers are sent through a combing or carding unit which further breaks apart and aligns the staple fibers in the machine direction so as to form a machine direction-oriented fibrous nonwoven web. Once the web has been formed, it is then bonded by one or more of several bonding methods. One bonding method is powder bonding wherein a powdered adhesive is distributed through the web and then activated, usually by heating the web and adhesive with hot air. Another bonding method is pattern bonding wherein heated calendar rolls or ultrasonic bonding equipment are used to bond the fibers together, usually in a localized bond pattern though the web can be bonded across its entire surface if so desired. The best method though, when using bicomponent staple fibers is to use a through-air bonder such as is described above with respect to the bicomponent spunbond web formation process. In order to maintain the lofty and open nature of the resultant fibrous nonwoven web according to the present invention, the bonding process used to bond the fibers of the fibrous nonwoven web together should be a process such as through-air bonding which does not unduly compress or collapse the structure during the formation process. ... In addition they may be made from a single fiber polymer or from multiple polymers such as are commonly found in biconstitutent and bi- or multicomponent fibers. When using bicomponent fibers, fiber cross-sections may include, for example, sheath/core, side-by-side and islands-in-the-sea cross-sections. The resultant fibrous nonwoven web will generally be a homogenous single layer blend of whatever type fiber or fibers are chosen. It is also possible, however, to form multilayer structures provided they meet the parameters set forth with respect to the present invention. To facilitate the through-air bonding process, it has been found advantageous to use bicomponent fibers which have both a higher melting point and lower melting point component such as in a side-by-side, sheath/core or islands-in-the-sea configurations. ... 3.0-denier by 38 millimeter polypropylene sheath/polypropylene core bicomponent fiber. The web was bonded using hot air at a temperature of 135.degree. C. for approximately 4 seconds. The test results for this material are set forth in Table 1. In Example 6, a homogeneous single-layer fibrous nonwoven web having a basis weight of 51.9 gsm was created using 20 percent by weight of the Hoechst Celanese type 295 6.0-denier polyester fibers; 20 percent by weight of the Hoechst Celanese type 183 1.5 denier polyester fibers and 60 percent by weight of the BASF 3.0-denier polyethylene sheath/polyester core bicomponent fibers. The homogeneous blend of fibers was bonded together using hot air at a temperature of 135.degree. C. for approximately 4 seconds. The test results for this material are set forth in Table 1. ``` TABLE 1 __________________________________________________________________________
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23Web page: Patents Assigned to Kimberly-Clark Corporation - Justia Patents Search, patents.justia.com
The sheath intercepts body fluid in the vagina and directs it to the external pad. A conducting layer conducts fluid so intercepted by the sheath to an absorbing surface on the interior of the external pad, the interior absorbing surface being displaced from the user's body by a primary mass of an absorbent layer. **Type:** Grant **Filed:** October 20, 1993 **Date of Patent:** February 14, 1995 **Assignee:** Kimberly-Clark Corporation **Inventors:** John P. Vukos, Billie D. Matelski * ###### [Process for making a high pulp content nonwoven composite fabric](https://patents.justia.com/patent/5389202) **Patent number:** 5389202 **Abstract:** A high pulp content nonwoven composite fabric is disclosed. The composite fabric contains more than about 70 percent, by weight, pulp fibers which are hydraulically entangled into a continuous filament substrate. This high pulp content composite nonwoven fabric may be used as a heavy duty wiper or as a fluid distribution material, cover material, and/or absorbent material in an absorbent personal care product. Also disclosed is a method of making the high pulp content nonwoven composite fabric. **Type:** Grant **Filed:** June 9, 1993 **Date of Patent:** February 14, 1995 **Assignee:** Kimberly-Clark Corporation **Inventors:** Cherie H. Everhart, Daniel O. Fischer, Fred R. Radwanski, Henry Skoog * ###### [High surface area iron-magnesium smoke suppressive compositions](https://patents.justia.com/patent/5386838) **Patent number:** 5386838 **Abstract:** A high surface area oxidative catalyst smoke suppressive composition, smoke suppressive articles, and method of making such compositions and articles are disclosed. ... **Abstract:** The application is directed toward a process for forming an electret filter medium. **Type:** Grant **Filed:** September 23, 1992 **Date of Patent:** December 6, 1994 **Assignee:** Kimberly-Clark Corporation **Inventors:** Lee K. Jameson, Bernard Cohen * ###### [Repellent-treated, barrier-coated nonwoven web](https://patents.justia.com/patent/5370132) **Patent number:** 5370132 **Abstract:** Disclosed herein is a repellent-treated, barrier coated nonwoven web. Nonwoven webs with small fiber and pore sizes can often be surface coated with a barrier coating such as latex to form a nonwoven which will act as a barrier to liquids. Surface coating of nonwovens having larger pores and fibers is more difficult as the coating often sinks into the thickness of the nonwoven web. The material of the present invention is a larger fiber/pore nonwoven web which will permit surface coating to form a material which has a good hand and cloth-like feel while also acting as a barrier to liquids. Such a material has a wide variety of applications including, but not limited to, personal care products, surgical drapes and gowns and other applications requiring barrier properties. **Type:** Grant **Filed:** November 20, 1990 **Date of Patent:** December 6, 1994 **Assignee:** Kimberly-Clark Corporation **Inventors:** Robert E. Weber, Steven W. Fitting, Patricia A. Jegier * ###### [Garment of durable nonwoven fabric](https://patents.justia.com/patent/5366786) **Patent number:** 5366786 **Abstract:** There is disclosed a thermally bonded spunbond web of thermoplastic filaments and a nonwoven fabric laminate comprising an internal layer of meltblown thermoplastic microfibers sandwiched between two layers of spunbond thermoplastic filaments. ... **Abstract:** A structure for selectively absorbing an oily contaminant from an aqueous environment comprising a plurality of sheets of nonwoven oleophilic fibers arranged in superposition to form a generally rectangular parallelpiped shape, the configuration may be maintained in shape and has a major surface formed by sheet edges so that when contacting an oily containment, the contaminant is selectively absorbed into the structure through wicking action. These structures may be combined to form booms or the like and stacked in a particular configuration for easy storage, transportation and deployment. **Type:** Grant **Filed:** April 6, 1993 **Date of Patent:** November 15, 1994 **Assignee:** Kimberly-Clark Corporation **Inventor:** James D. Cotton * ###### [Absorbent structure having improved fluid surge management and product incorporating same](https://patents.justia.com/patent/5364382) **Patent number:** 5364382 ... Due to the materials and nature of construction, the stockinette of the present invention provides a form-fitting design which is easy to don and remove. **Type:** Grant **Filed:** June 30, 1993 **Date of Patent:** November 8, 1994 **Assignee:** Kimberly-Clark Corporation **Inventors:** Stacey G. McCarver, David C. Strack, Marsha L. Porter, Peter Mathis [prev](https://patents.justia.com/assignee/kimberly-clark-corporation?page=18) … [15](https://patents.justia.com/assignee/kimberly-clark-corporation?page=15) [16](https://patents.justia.com/assignee/kimberly-clark-corporation?page=16) [17](https://patents.justia.com/assignee/kimberly-clark-corporation?page=17) [18](https://patents.justia.com/assignee/kimberly-clark-corporation?page=18) 19
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24Web page: Latex coated breathable barrier - Kimberly-Clark Corporation, freepatentsonline.com
Latex coated breathable barrier - Kimberly-Clark Corporation In preferred embodiments, the porous sheet is a meltblown nonwoven web. The disclosed breathable barrier is especially useful as outer covers and baffles in such disposable absorbent articles as diapers, sanitary napkins, and incontinent pads
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57Web page: Nonwovens Standard Procedures (nonwovens test methods), edana.org
contrast-ratio opacity of the dry white sheet; no standard measures stain masking or see-through of a soiled absorbent product.
Why it’s hereStandard dry-sheet opacity tests; no standard measures stain masking of a soiled product.
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58Paper: Porous polymeric microparticles foamed with supercritical CO2 as scattering white pigments, Borgmann et al.2023
L. Borgmann, S. Johnsen, C. S. d. Oliveira and 5 moreBioinspiration & Biomimetics
Air-filled nano-scale cavities scatter broadband light, presented explicitly as 'a possible replacement for TiO₂ pigments'.
Why it’s hereAir-filled cavities in foamed microspheres scatter light, an alternative route to white pigment.
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59Paper: Preparation and Applications of Electrospun Optically Transparent Fibrous Membrane, Xiao et al.2021
Y. Xiao, H. Luo, R. Tang and 1 morePolymers
Transmittance falls as areal density rises; the web dense enough to be opaque is the web that is stiff and low-permeability.
Why it’s hereShows nanofibre web opacity rises with areal density, tying opacity to stiffness and low permeability.
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60Web page: NWSP 402.0 Cup Crush » SGS-IPS Testing, ipstesting.com
The material must have sufficient structural integrity to be formed into the cup shape and then be able to maintain that shape until it is tested. ... A 225-mm square specimen ... A 44.5 mm diameter hemispherical-shaped plunger
Why it’s hereDefines the cup crush softness test: specimen, plunger and peak-load measure.
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61Paper: Fiber Selection for Reinforced Additive Manufacturing, Beckman et al.2021
I. P. Beckman, C. M. Lozano, E. Freeman and 1 morePolymers
Fiber flexural rigidity ∝ d⁴; bonding adds a torsion term to web bending rigidity; frictional sound correlates with friction, roughness, shear and bending rigidity.
Why it’s hereFibre bending stiffness scales with diameter to the fourth power; bonding adds web stiffness.
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62Paper: Liquid-liquid displacement in slippery liquid-infused membranes (SLIMs)., Bazyar et al.2018
H. Bazyar, P. Lv, J. A. Wood and 3 moreSoft Matter
pores will be opened corresponding to the capillary pressure, leading to preferential flow pathways... The remaining infusion liquid is retained as pools, bridges and thin films around pillar structures... consistent with an invasion percolation with trapping (IPT) model.
Why it’s hereShows displaced infusion liquid stays as films and bridges, opening preferential paths by capillary pressure.
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63Paper: A review on nature-inspired gating membranes: From concept to design and applications., Bazyar et al.2022
H. Bazyar, O. Moultos and R. LammertinkJournal of Chemical Physics
slippery liquid-infused membranes (SLIMs)... also known as liquid gating membranes due to the gating functionality of the capillary-stabilized liquid in the membrane pores... the pores open and close in response to the ambient stimuli, e.g., pressure, temperature, and ions.
Why it’s hereReviews liquid-gated membranes whose pores open and close under pressure, temperature or ions.
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64Paper: Metallic Liquid Gating Membranes., Tesler et al.2020
A. B. Tesler, Z. Sheng, W. Lv and 5 moreACS Nano
The mechanical integrity of most polymeric membranes can be compromised by deformation under harsh operating conditions (elevated temperatures, corrosive environments, foulants, etc.), ultimately leading to their failure... metal-based membrane systems significantly extend the operating range of LGMs.
Why it’s hereMetal-based liquid-gated membranes, noting polymer supports can deform and fail under harsh conditions.
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65Paper: Liquid gated membrane with self-cleaning properties for controllable removal and multi-component separation of organic/bacterial contaminants, Li et al.2024
R. Li, L. Zhao, L. Wang and 5 moreJournal of Membrane Science
When the pressure exceeds a critical breakthrough pressure, the liquid lined pores are formed... The effective pore size of LGM increases with increasing pressure. When the pressure is removed, the liquid refilling that leads to pore-closing is promoted by lower lubricant viscosity and larger effective pore size.
Why it’s hereShows pores reseal after pressure removal, faster with lower viscosity and larger pores: self-resealing.
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66Paper: Designing Transmembrane Critical Pressure in Bioinspired Liquid Gating Membranes, Jiang et al.2026
Y. Jiang, X. Li, C. Ye and 4 moreMaterials Chemistry Frontiers
Bioinspired liquid gating, inspired by pulmonary alveoli, employs a functional gating liquid that is capillary-stabilized within the pores of a porous membrane, forming a pressure-driven liquid gate to achieve reversible...
Why it’s hereDescribes how to design the critical pressure of liquid-gated membranes.
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67Paper: Exploiting the interfacial instability of liquid-infused Janus membranes for versatile liquid gating., Deng et al.2025
W. Deng, R. Guo, G. Wang and 3 moreJournal of Colloid and Interface Science
liquid fouling usually results in the alteration of surface wettability and thereby leads to the failure of gating properties either in air or in liquids.
Why it’s hereShows liquid fouling changes wettability and can make liquid gating fail.
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68Paper: Client Challenge
Liquid-filled pores in membranes have been designed to reversibly open and close, allowing only particular fluids through at given pressures. This enables tunable and gated separations.
Why it’s hereCommentary introducing liquid-filled pores that open for particular fluids at set pressures.
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69Paper: Theoretical assessment and experimental analysis of liquid entry pressure in membrane distillation process, Park et al.2017
C. Park, D. Shin, C. Lee and 2 moreDesalination and Water Treatment
contact angle and liquid entry pressure of all composite membranes... exceeded 160 degrees and 0.3 MPa... composite membranes with larger support pore size... had higher membrane distillation flux
Why it’s hereTheory and measurement of liquid breakthrough pressure in membrane distillation composites.
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70Web page: Fluid-based gating mechanism with tunable multiphase selectivity and antifouling behavior - President and Fellows of Harvard College, freepatentsonline.com
A gating mechanism that uses a capillary stabilized liquid as a reversible, reconfigurable gate that fills and seals pores in the closed state, and creates a non-fouling, liquid-lined pore in the open state
Why it’s hereHarvard patent claiming the capillary-held liquid gate that seals pores closed and lines them open.
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71Paper: Durability of Slippery Liquid-Infused Surfaces: Challenges and Advances, Tripathi et al.2023
D. Tripathi, P. Ray, A. Singh and 2 moreCoatings
The greatest limitation is the loss of lubricant due to evaporation, displacement, cloaking, or any other mechanism ... the retention of the lubricant is essential
Why it’s hereReviews lubricant loss as the main limitation of liquid-infused surfaces; retention is essential.
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72Paper: Toward sustainable and durable liquid-infused surfaces: a review of lubricant-depletion mitigation strategies., Liang et al.2025
S. Liang, X. Zhao, W. Zhang and 3 moreChemical Communications
the infused lubricant in SLIPS is prone to depletion over time due to factors such as evaporation, dissolution, shear-induced displacement, and cloaking effects
Why it’s hereReviews depletion mitigation: pore structure, infusion method and lubricant anchoring, as the design uses.
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73Paper: Alcohol-gating femtosecond laser-induced micro/nano-structured membranes with reversible switching wettability and breathability., Pei et al.2024
J. Pei, K. Yin, X. Song and 5 moreMaterials Horizons
A reversible liquid gating membrane with the ability to regulate gas/liquid transport is critical for many fields... the porous membrane... exhibits excellent superhydrophobicity and breathability (water-vapor evaporation rates ~118.3 mg (cm2 h)-1), enabling gas to penetrate but not water... Significantly, the porous membrane has broad potential applications in medical dressings.
Why it’s hereBreathable switchable liquid-gating membrane for dressings, letting gas but not water through.
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74Paper: Liquid-infused interfacial floatable porous membrane as movable gate for ultrafast immiscible oil/water separation, Yang et al.2024
J. Yang, X. Yang, T. Yu and 1 moreScientific Reports
Liquid-infused porous membranes have been developed, in which the lubricant liquid within the membrane acts as a reconfigurable barrier... They suffer from several issues. For example, perfluorinated fluids are currently required for the liquid, and the pressure must be precisely adjusted to control the gating threshold.
Why it’s hereNotes liquid-infused membranes have needed perfluorinated fluids and precisely tuned gating pressure.
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75Patent: Slippery liquid-infused porous surfaces having improved stability, US 9,630,2242013
Harvard UniversityInventors: J. Aizenberg and N. Vogel
Methods and articles disclosed herein relate to liquid repellant surfaces having selective wetting and transport properties. An article having a repellant surface includes a substrate comprising surface features with re-entrant curvature and an immobilized layer of lubricating liquid wetting over the surface features.
Why it’s hereHarvard patents on stable liquid-infused surfaces with immobilised lubricant on textured substrates.
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76Web page: Air Through Bond Nonwoven, generalnonwovens.com
Why it’s hereCommercial through-air-bonded nonwoven offered for soft topsheets and backsheets.
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77Paper: Pore Size and Air Permeability of Four Nonwoven Fabrics, Epps & Leonas2000
H. Epps and K. Leonas
Minimum, maximum and mean flow pore sizes were determined using liquid porosimetry... For the spunlaced fabrics, air permeability was most highly correlated with mean flow pore size, while there was a significant correlation between air permeability and maximum pore size for the SMS fabrics.
Why it’s hereLinks measured pore sizes of nonwovens to their air permeability.
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78Web page: Spunbond Polypropylene Nonwovens Market in the European Union, indexbox.io
Standard grades (basis weight 15-50 gsm, non-treated) trade in the range of EUR 2.50-4.00 per kg for full truckload orders.
Why it’s hereMarket price range for standard spunbond nonwovens, a cost reference for the fibre web.
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79Paper: Direct observation of nanoparticle-surfactant assembly and jamming at the water-oil interface, Chai et al.2020
Y. Chai, J. Hasnain, K. Bahl and 5 moreScience Advances
For the water-silicone oil interface of interest in this study, gamma ~ 40 mN m-1.
Why it’s hereReports water–silicone oil interfacial tension near 40 mN/m.
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80Paper: Estimation of liquid entry pressure in hydrophobic membranes using CFD tools, Yazgan-Birgi et al.2018
P. Yazgan-Birgi, M. I. H. Ali and H. A. ArafatJournal of Membrane Science
The Franken model, which is a widely used approach for LEP estimation... LEP is in Pa, B is the pore geometry factor, theta the intrinsic contact angle, gamma the liquid surface tension, and r the radius of the largest membrane pore.
Why it’s hereBreakthrough pressure model with pore geometry factor, estimated using CFD tools.
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81Paper: Capillary Hysteresis in Neutrally Wettable Fibrous Media: A Pore Network Study of a Fuel Cell Electrode, Tranter et al.2017
T. Tranter, J. Gostick, A. Burns and 1 moreTransport in Porous Media
The classic Washburn relation was shown to produce erroneous results, and its use is not recommended when modelling fibrous media. The toroidal model predicts that the meniscus will advance past the throat apex before reaching the critical or breakthrough pressure, increasing curvature due to the locally diverging geometry.
Why it’s hereInterface passes the pore neck before breakthrough; the standard Washburn capillary-flow equation gives wrong results for fibrous media.
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82Paper: Stability-optimized design of lubricant-impregnated surface with microcavity topography inspired by orange peel, Hu et al.2025
H. Hu, Y. Lu, L. Guo and 2 moreColloids and Surfaces A: Physicochemical and Engineering Aspects
the depletion of infused lubricants through evaporation, displacement, and shear can significantly degrade their interfacial slipperiness.
Why it’s hereLubricant loss by evaporation, displacement and shear degrades infused surfaces; design for stability.
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83Paper: Shear-driven failure of liquid-infused surfaces., Wexler et al.2015
J. Wexler, I. Jacobi and H. StonePhysical Review Letters
liquid-infused surfaces exhibit a new failure mode: the infused liquid film may drain due to an external shear flow, causing the surface to lose its advantageous properties.
Why it’s hereShows external shear flow can drain the infused film, a failure mode for the gel.
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84Patent application: Barrier Fabrics with Desirable Air Permeability, US 2024/0316898 A12024
Berry Global IncInventors: L. Wang, N. Bishop, T. ZHANG and 2 more
Each of the nonwoven layers being treated with a non-fluorinated barrier coating (NFBC) ... 45 gsm SMMMMS + NFBC at 81.2 mbar average hydrohead and 20.99 cfm, pore size 6–8 µm; outermost spunbond fibres with an average diameter from about 10 to about 25 microns, 18–22.
Why it’s hereFilm-free 45 gsm web with fluorine-free coating at 81.2 mbar hydrohead and 20.99 cfm.
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85Paper: Structure and Air Permeability of Melt Blown Nanofiber Webs, Han et al.2016
W. Han, X. Wang and G. Bhat
Meltblown fibers... evaluated the fabric structure, such as mean pore diameter and air permeability... the pore diameter and distribution were measured by an SFP-1100-AEX capillary flow porometer.
Why it’s hereShows pore size and distribution in meltblown webs track fibre diameter, sizing the vent zone.
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86Web page: Refractive index of TiO2 (Titanium dioxide) - Devore-o, refractiveindex.info
Why it’s hereRefractive index data for rutile titanium dioxide, the gel's white pigment.
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87Paper: Investigation of the anatase-to-rutile transition for TiO2 sol-gel coatings with refractive index up to 2.7, O'Byrne et al.2023
M. O'Byrne, B. Kerzabi, M. Abbarchi and 5 moreThin Solid Films
Why it’s hereTitanium dioxide coatings reaching refractive index up to 2.7.
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88Patent: Absorbent article with a channel-forming area and a masking layer, US 12,004,934 B22021
Procter and Gamble CoInventors: E. G. BIANCHI, M. K. Hippe, A. Chatterjee and 4 more
A separate masking layer between the absorbent core and a liquid-impermeable backsheet, opacity ≥~25%, air permeability >150 m³/m²/min, caliper 0.1–2.0 mm, 25–100 gsm.
Why it’s hereP&G masking layer: a separate ply between core and backsheet hides stains.
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89Patent: Use of stain masking backsheets in absorbent articles, US 6,362,390 B11998
Procter and Gamble CoInventors: G. Carlucci and M. Tamburro
Backsheet constructions comprising a three dimensional formed film… provide masking… when viewed through the garment facing surface.
Why it’s hereP&G stain masking via a three-dimensional formed film backsheet.
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90Patent: Dark-tinted nonwoven webs, US 12,042,3642020
Procter and Gamble CoInventors: N. S. Wimalasena
Dark-tinted nonwoven webs of the present disclosure may have a Hydrohead Value of between about 15 mbar and about 50 mbar.
Why it’s hereDark-tinted nonwovens with hydrohead of about 15 to 50 mbar.
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91Web page: NWSP 80.6 Water Resistance (Hydrostatic Pressure) Test, eurolab.net
Rate of increase of water pressure should be 10 ± 0.5 or 60 ± 3 cm H2O/min; using these two ratios can yield different results... A nylon mesh or mesh screen is sometimes used to support the sample... If this technique is used, it should be reported with the test results.
Why it’s hereHydrostatic test details: two ramp rates and reporting any support mesh.
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92Web page: Standard Test Method for Air Permeability of Textile Fabrics, astm.org
Air permeability ... can be used to provide an indication of the breathability of weather-resistant and rainproof fabrics.
Why it’s hereAir permeability standard as an indicator of fabric breathability.
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93Web page: ISO 9073-16:2007 - Textiles — Test methods for nonwovens — Part 16: Determination of resistance to penetration by water (hydrostatic pressure), iso.org
ISO 9073-16:2007 describes the hydrostatic pressure test that measures the resistance of nonwoven fabrics to the penetration of water under varied hydrostatic head pressures.
Why it’s hereHydrostatic pressure test for nonwovens, scoped to water only.
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94Paper: Surface Tension Properties of Human Urine: Relationship with Bile Salt Concentration, Mills et al.1988
C. Mills, E. Ellas, G. H. Martin and 2 moreJournal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie
The effect of ageing of the surface, of storage, of temperature, pH, dilution and albumin on urine surface tension are described.
Why it’s hereDescribes how ageing, temperature, pH and albumin change urine surface tension.
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95Web page: Air Permeability Conversion Factors, idfl.com
(ft3 /ft2 /min) x 5.08 = (L/m2 /sec)@125Pa
Why it’s hereConversion factors between imperial and metric air permeability units at stated pressure.
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96Patent application: Methods and apparatuses for forming corrugated thermoplastic sheets and cellular structures, US 2024/0316888 A12023
Spirit AeroSystems IncInventors: J. Garber, M. A. Wadsworth and B. J. Blonigen
Assigned to SPIRIT AEROSYSTEMS, INC.
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97Web page: NWSP 360.3.R0 (20), imisw.inda.org
Determination of Trace Chemicals Extracted from Absorbent Hygiene Products (AHPs) using Simulated Urine/Menses Part 3: Analysis of Trace Chemicals in Aqueous Extracts.
Why it’s hereSimulated urine/menses standard for extracting trace chemicals, not a pressure fluid.
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98Paper: Toward Long‐Lasting Slippery Surfaces for Condensation and Icephobicity: From Lubricant‐Infused to Liquid‐Like Surfaces, Kim et al.2025
J. S. Kim, S. Roh, K. Shim and 3 moreAdvanced Materials Interfaces
Design rules for LIS: employing closed-cell and hierarchical reservoirs to immobilize lubricants under shear.
Why it’s hereDesign rules using closed-cell and hierarchical reservoirs to hold lubricants under shear.
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99Patent application: Mechanical and internal softening for nonwoven web, US 5,770,531 A1996
Kimberly Clark Worldwide IncInventors: G. T. Sudduth and A. Yahiaoui
An absolute cup crush load value of about 70 grams or less is considered desirably soft for the purposes of this invention.
Why it’s hereA nonwoven softening patent treats cup crush of about 70 g or less as soft.
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100Web page: Per- and polyfluoroalkyl substances (PFAS) - ECHA, echa.europa.eu
ECHA supports PFAS restriction with targeted derogations, 26 March 2026; updated restriction proposal published 20 August 2025; risk assessment committee opinion adopted 3 March 2026; textiles among the sectors evaluated.
Why it’s hereEU PFAS restriction timeline with textiles among assessed sectors, motivating fluorine-free chemistry.
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101Web page: ECHAs update on the REACH restriction on PFAS, efsa.europa.eu
RAC adopted opinion 2 March; SEAC agreed draft opinion 10 March; SEAC final opinion by end 2026. Covers full scope of the proposal.
Why it’s hereUpdate on EU PFAS restriction committee opinions, final opinion due end 2026.
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102Paper: Fluorine-free hydrophobic powder coatings: a sustainable approach using functionalized biogenic SiO2 for anticorrosion and antifouling applications, Nazarlou et al.2025
Z. Nazarlou, H. Najjari, A. Olad and 1 moreSurfaces and Interfaces
The incorporation of silane-functionalized biogenic SiO₂ nanoparticles produced hydrophobic surfaces, with the highest CA of 144° achieved at a 20 wt. % HTMS-SiO₂ loading.
Why it’s hereFluorine-free silane-treated silica coatings reaching 144° water contact angle.
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103Patent application: Dispersion, production method therefor, and cosmetic, WO 2016121761 A12016
Sakai Chemical Industry Co LtdInventors: 佐野晃文 and 小野啓治
A dispersion having inorganic oxide particles dispersed in an oil-based medium and containing a C18 or higher ester oil and a polyhydroxystearic acid ... a dispersion is obtained using polyhydroxystearic acid as a dispersant.
Why it’s hereDisperses inorganic oxide particles in oil with polyhydroxystearic acid, a route for pigment in gel.
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104Patent: Slippery liquid-infused porous surfaces and biological applications thereof, US 9,932,484 B22012
Harvard UniversityInventors: J. Aizenberg, B. Hatton, D. Ingber and 2 more
SLIPS are synthetic surfaces that consist of nano/microstructured substrates infused with a lubricating fluid that is locked in place by a substrate to form a stable, defect-free, inert 'slippery' interface capable of repelling complex fluids, gases, and molecules or particulates contained within liquids of varying surface tensions.
Why it’s herePatent family on liquid-infused porous surfaces repelling fluids of varied surface tension.
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105Web page: INDA, Association of the Nonwoven Fabrics Industry - Cary, NC - Test Method Approach, inda.org
It is important to emphasize that there is no standard 'synthetic urine,' because th...
Why it’s hereNonwovens industry note that no standard synthetic urine exists.
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106Web page: TABLE OF CONTENTS Harmonized Nonwovens Standard Procedures Editions 2015 and forward, edana.org
REPELLENCY: NWSP 080.5 Saline Repellency; NWSP 080.6 Evaluation of Water Resistance (Hydrostatic Pressure); NWSP 080.7 Penetration by Oil; NWSP 080.8 Alcohol Repellency.
Why it’s hereLists harmonised nonwoven repellency procedures including hydrostatic pressure and oil penetration.
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107Paper: Rheological and interfacial characterization of menstrual fluid, Pero et al.2026
E. Pero, C. Neu, A. Wolf and 3 moreThe Physics of Fluids
Menstrual fluid viscosity is approximately fourfold higher than blood and forty-fold higher than water … Surface tension is significantly lower than that of water and comparable to that of venous blood … Current industrial simulants are typically simplified water- or blood-like fluids that may not adequately reproduce the complex behavior of real menses.
Why it’s hereMenstrual fluid is far more viscous than water, with lower and broader surface tension.
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108Patent application: Menstrual fluid simulant, US 2024/0151706 A12023
Procter and Gamble CoInventors: J. Claussen, B. Mohebbi, C. Neu and 5 more
a viscosity that is shear-dependent and ranges from about 10 mPas to about 140 mPas, at 21° C. and a shear rate of 10 s−1, a surface tension that ranges from about 35 mN/m to about 70 mN/m
Why it’s hereP&G menstrual simulant with defined viscosity and 35 to 70 mN/m surface tension.
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109Web page: NWSP 360.2.R0 (20), imisw.inda.org
Determination of Trace Chemicals Extracted from Absorbent Hygiene Products (AHPs) using Simulated Urine/Menses Part 2: Extraction of Trace Chemicals for Homogenized AHPs into a Simulated Urine/Menses Solution.
Why it’s hereUrine/menses simulant standard for chemical extraction, showing no pressure-fluid standard exists.
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A pore-held silicone gel gives a soft web its barrier