What is a Gore-Tex made of?
What is a Gore-Tex made of?
A stretched PTFE membrane whose pores are far too small for a raindrop and far too big for a water vapour molecule.
The single most misunderstood thing about a waterproof-breathable jacket is that when it stops working, the membrane is almost never the problem. The DWR on the outer fabric wears off, the face fabric soaks up water, and vapour from inside can no longer evaporate away — the jacket feels clammy and gets blamed for leaking. Washing with a technical cleaner and reproofing usually restores it. Bob Gore discovered the expansion process in 1969 by yanking heated PTFE rod instead of stretching it slowly, and the same ePTFE is used in vascular grafts, dental floss and industrial filtration. Gore has been moving its consumer membranes to expanded polyethylene to eliminate PFAS from the product line.
Component by component
| Part | Material | Why that material |
|---|---|---|
| membrane | expanded polytetrafluoroethylene (ePTFE), stretched to a microporous film | The pores are roughly 0.2 µm across — around 20,000 times smaller than a raindrop and hundreds of times larger than a water vapour molecule. |
| oleophobic layer | a thin polyurethane layer laminated to the membrane | Skin oils and detergents would otherwise wet the PTFE and let water through; this layer blocks them at a small cost in breathability. |
| face fabric | nylon or polyester, laminated to the membrane | The membrane is too delicate to be a garment; the face fabric takes the abrasion and the membrane does the work. |
| backer | a knit or printed liner in three-layer construction | It protects the inner face of the membrane from abrasion and body oils, which is why three-layer shells outlast two-layer ones. |
| DWR | a durable water repellent finish on the outer fabric | If the face fabric wets out, the water film blocks vapour transfer and the jacket feels like it is leaking when it is not. |
Other clothing and kit objects
- Velcro (hook and loop) Two nylon tapes — one of stiff hooks, one of soft loops — copied directly from burdock burrs.
- Leather Animal hide whose collagen has been chemically stabilised so it cannot rot — usually with chromium salts.
- Denim A cotton twill with indigo-dyed warp and undyed weft — the dye sits on the fibre surface, which is why it fades.
- Helmet A hard shell to spread the blow over a crushable polystyrene foam liner that is destroyed by one impact.
- Bulletproof vest Many layers of woven aramid or polyethylene fibre that catch and deform a bullet; rifle threats need a ceramic plate.
- Zip (zipper) Teeth of metal, moulded acetal or nylon coil on a polyester tape, forced together by a wedge inside the slider.
- Synthetic leather A polyurethane or PVC skin on a textile backing — including the plant-based ones, which still need a plastic binder.
- Running shoe A knitted synthetic upper over a foam midsole and rubber outsole — about a dozen materials, all glued together.
- Shoe sole A rubber outsole for grip, a foam midsole for cushioning, and increasingly no clean way to separate them.
- Wetsuit Closed-cell neoprene foam full of nitrogen bubbles, faced with stretch jersey — the gas insulates, not the water.
- Life jacket Closed-cell foam or a CO2-inflated bladder, in a nylon cover — rated in newtons of buoyancy, not in size.
- Button Usually cast polyester resin; the good ones are shell, nut or horn, and you can tell by touch and temperature.
Common questions
- What is a Gore-Tex made of?
- A stretched PTFE membrane whose pores are far too small for a raindrop and far too big for a water vapour molecule.
- What is the membrane of a Gore-Tex made of?
- Expanded polytetrafluoroethylene (ePTFE), stretched to a microporous film. The pores are roughly 0.2 µm across — around 20,000 times smaller than a raindrop and hundreds of times larger than a water vapour molecule.
- What is the oleophobic layer of a Gore-Tex made of?
- A thin polyurethane layer laminated to the membrane. Skin oils and detergents would otherwise wet the PTFE and let water through; this layer blocks them at a small cost in breathability.
Related pages
- Velcro (hook and loop) Two nylon tapes — one of stiff hooks, one of soft loops — copied directly from burdock burrs.
- Leather Animal hide whose collagen has been chemically stabilised so it cannot rot — usually with chromium salts.
- Denim A cotton twill with indigo-dyed warp and undyed weft — the dye sits on the fibre surface, which is why it fades.
- Helmet A hard shell to spread the blow over a crushable polystyrene foam liner that is destroyed by one impact.
- Bulletproof vest Many layers of woven aramid or polyethylene fibre that catch and deform a bullet; rifle threats need a ceramic plate.
- Zip (zipper) Teeth of metal, moulded acetal or nylon coil on a polyester tape, forced together by a wedge inside the slider.
- Synthetic leather A polyurethane or PVC skin on a textile backing — including the plant-based ones, which still need a plastic binder.
- Running shoe A knitted synthetic upper over a foam midsole and rubber outsole — about a dozen materials, all glued together.
- Pencil Stationery and paper
- Tennis ball Sport and games
- Banknote Around the house
- Golf ball Sport and games
- Paper Stationery and paper
- Glass Building materials
Sources
- Official vendor product documentation — At One Place