Glossary term
ePTFE
Also known as: Expanded PTFE
Expanded polytetrafluoroethylene — a microporous, hydrophobic membrane chemistry at the heart of many waterproof-breathable laminates.
Definition
ePTFE membranes contain billions of microscopic pores per square centimetre — too small for liquid water to penetrate under normal pressure, but large enough for water vapour molecules to pass through.
ePTFE is durable and high-performing; it is also specialised to manufacture and typically requires a protective oleophobic coating.
Why it matters to DSEAMS
DSEAMS construction is compatible with ePTFE laminates and preserves the membrane's performance across every bonded seam.
Related terms
- Barrier membraneThe thin functional layer inside a laminate that blocks liquid water while allowing vapour to pass.
- PU membraneA hydrophilic or microporous polyurethane film used as the barrier in waterproof-breathable laminates — typically lighter, stretchier and less expensive than ePTFE.
- Laminate constructionA textile assembled from two or more layers bonded together — typically a face fabric, a membrane and a lining or backer.