Waterproof Breathable Technology
A technical comparison of durability, breathability, and performance between the dominant waterproof breathable membrane technologies used in functional fabric manufacturing.
Technology Overview
PU (Polyurethane) Membranes
PU membranes are hydrophilic films that absorb moisture vapor from the warm interior and transfer it through the membrane to the cooler exterior. They offer a cost-effective solution for moderate-performance waterproof breathable fabrics. Available in solid film and microporous variants.
Advantages: Lower cost, easier to manufacture, good flexibility, available in 2-layer and 3-layer configurations.
PTFE (Polytetrafluoroethylene) Membranes
PTFE membranes use microporous technology — millions of microscopic pores per square inch that are 20,000x smaller than a water droplet but 700x larger than a water vapor molecule. This allows moisture vapor to escape while preventing liquid water penetration.
Advantages: Highest breathability, excellent waterproofness, no chemical additives required.
ePTFE (Expanded PTFE) Membranes
ePTFE is an advanced form of PTFE that has been mechanically expanded to create an even more porous structure with higher MVTR. It is the premium choice for high-performance outdoor and tactical applications.
Advantages: Maximum breathability, superior waterproofness, excellent durability.
Side-by-Side Comparison
| Property | PU | PTFE | ePTFE |
|---|---|---|---|
| Hydrostatic Head | 5000-15000mm | 10000-20000mm | 15000-30000+mm |
| MVTR (g/m²/24hr) | 5000-10000 | 10000-20000 | 15000-30000+ |
| Cold Flexibility | -20°C | -40°C | -40°C |
| Durability | Good | Very good | Excellent |
| Cost (per m²) | $5-10 | $10-20 | $15-30 |
| Eco-Friendliness | Moderate | PFC concerns | PFC concerns |
| Best For | Value outerwear | Performance gear | Premium/professional |
Which Should You Choose?
Choose PU When:
- Budget is the primary concern
- Moderate breathability is acceptable
- Applications include everyday outerwear, light rain protection
Choose PTFE When:
- High breathability is required for active use
- Reliable waterproofness for outdoor adventures
- You need a proven technology with established performance
Choose ePTFE When:
- Maximum breathability for high-output activities
- Professional or tactical applications requiring extreme reliability
- Cold-weather performance below -20°C
Seekingtex Recommendation
For most outdoor and activewear applications, PTFE membranes offer the best balance of performance and value. Seekingtex uses PU membranes for entry-level products, PTFE membranes for mid-range performance gear, and advanced laminated constructions for premium and professional product lines.