A film-free fiber outercover that blocks body fluids, hides stains and stays soft
A diaper or pad outercover with no plastic film has to hold back urine, stool and menses at 62 millibar of pressure, hide stains, and stay soft, quiet and breathable, for under seven euro cents per square metre. The fiber density, extra fine-fiber layers and coatings that stop liquid and block light also stiffen the web and raise its cost.
Today a thin laminated polymer film carries the barrier and the masking, and the film-free webs that reach the barrier rely on stacked fine-fiber layers plus water-repelling finishes; the best measured one is estimated to cost two to three times the ceiling.
Six ideas
- Idea 01Borrowed from springtail skin and biomimetic surface engineering
Fine-filament lid over washed-out cavities repels fluid by shape
Borrowing the overhanging bumps that keep springtail skin dry in rain, we build a film-free fabric whose narrow mouths over hidden cavities hold back body fluids by shape.
Seen working in Hygiene and barrier nonwovens · Nonwoven fibre and fabric patents · Microfabrication on textilesOpen idea → - Idea 02Borrowed from papermaking internal sizing chemistry
Paper sizing wax that grows a liquid barrier after bonding
Borrowing papermaking's internal sizing, we let a water-repelling wax spread over the fibres after bonding, so a film-free web may hold back liquid with its pores left open.
Seen working in Papermaking wet-end chemistry · Paper sizing physics · Surface spectroscopy of paper sizingOpen idea → - Idea 03Borrowed from plant physiology of conifer wood
Pressure-driven foam plugs make a breathable nonwoven liquid-tight
Borrowing the bordered pit valve of conifer wood, we seat a foam plug in each pocket of a film-free web, so liquid pressure seals it while dry areas breathe.
Seen working in Conifer wood water transport · Nonwoven converting and polymer weldingOpen idea → - Idea 04Borrowed from snow physics and capillary barrier hydrology
Trapped air in fine fibres blocks liquid and hides stains
Borrowing how layered snow holds meltwater while air passes through, we split a film-free sheet into a fine barrier layer over a coarse reservoir layer, aiming to meet barrier, hiding and breathability together.
Seen working in Nonwoven fibre production · Snow and soil hydrology · Hygiene nonwovensOpen idea → - Idea 05Borrowed from dense-woven natural-fibre weatherproof textiles
A thin sheet that seals its own pores when wetted
Borrowing the swelling cotton fabric that keeps aircrew dry, we build a film-free swell-to-seal web whose fibres close its pores on wetting, meant to hold liquid back while staying breathable when dry.
Seen working in Weatherproof clothing textiles · Cellulose fibre science · Absorbent hygiene materialsOpen idea → - Idea 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.
Seen working in Hygiene nonwovens · Membrane scienceOpen idea →
