Types of Membranes: There are two main classes: Laminates and Coatings. Laminates are made of Polytetrafluoroethylene (PFTE) aka Teflon, Polyurethane (PU) films, or Polyester films. These are sheets of material that are fixed to the back of a fabric. Coatings are painted on the back of a fabric and are made of Polyurethane.
Types of DWR: There are two main classes: Fluorinated aka Perfluorinated Chemicals (PFC’s) and non-fluorinated (PFC-Free). You may have heard the terms “C8” aka “Long Chain PFC’s” or “C6” aka “Short-Chained PFC’s.” PFC’s have been used in DWR for decades and are not isolated to outerwear intended for snow or rain. They’re everywhere - carpets, furniture, and non-stick pans to name just a few items.
Recently, we’ve learned that PFC’s are persistent and hazardous to the environment. After learning this we migrated from “C8” to “C6” DWR as did most of the outdoor industry. Though still a PFC, “C6” PFC’s are thought to be less problematic to the environment than “C8.” The jury is still out on whether they are actually better in this capacity. Therefore, we’ve made a commitment to fully migrate all of our products, including our board waxes and the garment after-care products we recommend to be PFC-free by 2020.
How do we Measure Waterproofing, Water Resistance, and Breathability?
Water ‘Proofing” or “Resistance” is measured on a pressure scale of millimeters (mm) of water. Standard snow outerwear ratings range from 5,000mm (5K) to 20,000mm (20K). By way of example, a 10K rating means it takes a 10,000mm cylinder of water over a 1 sq. inch of a piece of “10K” fabric for water to penetrate that fabric. The higher the number, the more water resistant the fabric. This is represented by the first number in the sequence. Identically, the second number in the sequence represents the layer’s “breathability” or ability to allow evaporated moisture to move from the interior of the fabric to the exterior. This is simply taking advantage of the natural processes of equilibrium where things (water in this instance) generally want to move from areas of higher concentration to lower concentration.
- 20K/10K – Wet Snow, Rain.
- 10K/5K – Above Average Snowfall, Light Rain.
- 5K – Dry Snow, Very Light Rain or mist.
- 600mm/600mm – Minimum to pass rain test.
- 20K+ -- Ultimate.
- 20K/10K – Premium.
- 10K/5K – Performance.
- 3K – Premium (for rain jackets).
Is your product not performing? See our article on Washing, Cleaning and Replenishing Water Repellency