Glossary term
PU membrane
Also known as: Polyurethane membrane
A hydrophilic or microporous polyurethane film used as the barrier in waterproof-breathable laminates — typically lighter, stretchier and less expensive than ePTFE.
Definition
Polyurethane membranes transport moisture by a combination of microporosity and hydrophilic chemistry. They are widely used in mid-market performance apparel.
PU membranes are generally more stretch-compatible than ePTFE, making them a common choice for soft-shell and hybrid constructions.
Why it matters to DSEAMS
DSEAMS bonded seams work with PU-based laminates, preserving their performance across the garment's seam network.
Related terms
- Barrier membraneThe thin functional layer inside a laminate that blocks liquid water while allowing vapour to pass.
- ePTFEExpanded polytetrafluoroethylene — a microporous, hydrophobic membrane chemistry at the heart of many waterproof-breathable laminates.
- Laminate constructionA textile assembled from two or more layers bonded together — typically a face fabric, a membrane and a lining or backer.