“Breathability” Comparison of Commercial …

1 breathability Comparison of Commercial Outerwear Shell Layers 1800. 1700. Conduit 1600 from Mountain Hardwear ( Lower Resistance is More "Breathable" ). 1500. Water Vapor Diffusion Resistance (s/m). Schoeller WB-Formula Sympatex Laminate 1400 (Schoeller Textiles). The North Face 1300 "Hydroseal". 1200 (Burlington "XALT"). 1100. Gore-Tex (Standard). 1000. Membrain from 900 Marmot 800 Entrant Dermizax (Toray Industries). 700 Omni-Tech "Titanium". 600 Gore-Tex XCR Columbia Sportwear 500 Lowe Alpine 400 Triplepoint Ceramic 300 Nextec from Patagonia "Velocity". 200 Entrant GII XT Laminate (Toray Industries). Schoeller Dryskin Extreme EVENT Laminate (BHA Technologies). 100 (Schoeller Textiles). Expanded PTFE Membrane 0. 0 Mean Relative Humidity (Average of Humidity on Both Sides of Sample) ( = 100% ).

2 7500. 7000 Expanded PTFE Membrane 6500. 6000 Schoeller Dryskin Extreme EVENT Laminate (Schoeller Textiles). 5500. Water Vapor Flux (g/m -day). (BHA Technologies). 5000. 2. Entrant GII XT Laminate Gore-Tex XCR. 4500 (Toray Industries). Gore-Tex (Standard). 4000. Dermizax 3500 (Toray Industries). Nextec from Membrain from 3000 Patagonia "Velocity" Marmot 2500 Sympatex (Akzo-Nobel). Lowe Alpine 2000 Triple Point Ceramic Conduit from Mountain Hardware 1500. Omni-Tech "Titanium". 1000 Columbia Sportwear 500 Schoeller WB-Formula The North Face "Hydroseal". (Schoeller Textiles) (Same as Burlington "XALT"). 0. 0 Mean Relative Humidity (Average of Humidity on Both Sides of Sample) ( = 100% ). Water Vapor Diffusion Test - Dynamic Moisture Permeation Cell Air at two different relative humidities flows over the two sides of the test sample.

3 By measuring the water vapor concentration at the exits of the cell, it is possible to measure how much water vapor crosses the sample. Results may be shown in terms of water vapor flux (grams/square meter/day) or resistance to the diffusion of water vapor (units of s/m). The resistance units make comparing results obtained at different environmental conditions much easier. The lower the diffusion resistance, the more water vapor gets through the material. The reason for doing the testing this way is that some materials like Gore-Tex, Sympatex, etc., have much better water vapor transport properties when they are in a humid environment than when they are in a dry environment, relatively speaking. Other materials, such as most textiles or microporous membranes, have a nearly constant water vapor diffusion resistance regardless of the environmental conditions Test Conditions Water Vapor Diffusion Temperature = 30 oC.

4 Gas Flow Rate = 2000 cm3/minute. Note: relative humidity of 100% is , so is 50% , etc. Setpoint # Humidity Humidity Mean Humidity on Top on Bottom Relative Gradient of Sample of Sample Humidity 1 2 3 4 5 Further details on the test method are available in the following references: Gibson, , "Effect of Temperature on Water Vapor Transport Through Polymer Membrane Laminates," Journal of Polymer Testing 19 (6), 2000. Gibson, , Rivin, D., Kendrick, C., "Convection/Diffusion Test Method for Porous Textiles," International Journal of Clothing Science and Technology 12 (2), 2000. Gibson, , "Water Vapor Transport and Gas Flow Properties of Textiles, Polymer Membranes, and Fabric Laminates," Journal of Coated Fabrics 28, April, 1999. Gibson, , Rivin, D., Berezin, A., Nadezhdinskii, A., "Measurement of Water Vapor Diffusion Through Laminated Fabrics and Membranes Using a Diode Laser Spectroscope,".

5 Polymer-Plastics Technology and Engineering 38 (2), 1999. Gibson, P., Kendrick, C., Rivin, D., "Apparatus and method for determining transport properties of porous materials," United States Patent 6,119,506, September 19, 2000. Dynamic Moisture Permeation Cell (DMPC). Conditioning Chamber and Sample Holder Phil Gibson Materials Science Team AMSRD-NSC-SS-MS. Army Soldier Systems Center Natick, MA 01760-5020. phone: 508-233-4273. fax: 508-233-5521. email.