If you are a true gear head, you are going to love this conversation. And if you aren’t a full-on gear nerd but you’d like to better understand what “waterproof” really means, and when you should and shouldn’t worry about a 10k or 20k rating on the jacket or pants you are thinking of buying, then you also ought to listen to this conversation.
Luke Koppa and I spoke this week with Michael Cattanach, who is the Product Design Director at Polartec. Polartec is a very interesting company with a hundred years of history behind it. But you might not be too familiar with them, since Polartec makes the textiles and fabrics that a lot of your favorite outerwear and apparel are made of, but they don’t make or sell the end products. In other words, Polartec makes the ingredients used to make your favorite apparel. And so today, we’re going to dive deep into the details about ingredients and textiles and fabrics, and Polartec’s history, and what Polartec is up to today.
Now as I said, we do get into the weeds quite a bit in this conversation, so we strongly encourage you to check out the show notes to this episode below, where we have listed a number of very relevant terms and definitions.
TOPICS & TIMES:
- History of Polartec (2:48)
- Michael’s background (6:52)
- History of NeoShell (8:44)
- Hydrostatic Head Pressure (14:31)
- MVTR & RET Tests (and see our Show Notes!) (18:34)
- Handfeel (28:53)
- “Electrospun” membranes (31:45)
- Polartec Power Shield Pro vs NeoShell (36:48)
- Being an “ingredient” brand (47:010
- Product control & Polartec’s Apex Awards (51:29)
- Polartec Power Fill, Alpha, & Power Air (59:20)
- Fleece, Microplastics, & Sustainability (1:03:13)
- Polartec.com – see the brands working with Polartec (1:10:32)
TERMS & DEFINITIONS
Terms Related to Testing, Ratings, Etc.:
- Air Permeability: A measure of how easily air passes through a textile or laminate. Typically, the more air-permeable a fabric is, the more breathable it is.
- CFM: Stands for “cubic feet per minute” and is a unit of measure for air permeability (i.e., how much air can pass through the fabric in a minute). CFM is often used interchangeably with air permeability.
- Hydrostatic Head: A measure of how waterproof a textile, laminate, or membrane is. The units usually represent how much water pressure a sample can withstand before leaking, and this rating is measured by placing a standardized-diameter water column on top of a fabric and filling the water column higher and higher with more and more water until water begins to penetrate the fabric. E.g., a fabric rated to a 10,000 mm (or 10K) hydrostatic head test can have a 10000mm-tall water column on top of it before it leaks, while a fabric rated 20,000 mm (or 20K) can support a 20,000 mm water column.
- MVTR: stands for “Moisture Vapor Transfer Rate” and is a general test used to show how much moisture can move through a fabric over a standardized period of time (typically 24 hours). The MVTR rating of most waterproof fabrics is typically described as g/m2/24hrs — the grams of moisture that are able to move through a square meter of fabric over 24 hours. If you see a fabric that says it has a “20K/20K” waterproof / breathability rating, the second “20K” typically refers to an MVTR value of 20,000 g/m2/24 hours. With that said, MVTR tests are extremely dependent on the testing conditions, which are not always standardized. The MVTR test is also not a perfect way to gauge how breathable a garment will feel when you’re wearing it (especially for air-permeable membranes), so we take this with a grain of salt.
- RET: “Resistance to Evaporative Heat Transfer.” While MVTR gauges how well or how much moisture vapor can move through a textile, RET is a way to gauge how much a textile resists moisture vapor transfer (i.e., how poorly moisture vapor moves through it). So while a higher MVTR value should translate to better breathability, a lower RET value should translate to better breathability. An RET value of 0 would suggest phenomenal breathability, while an RET value of 30 would suggest extremely poor breathability.
Terms Related to Waterproof Fabrics:
- Laminate: Refers to a composite sandwich of fabrics and / or membranes that are bonded together (usually via glue, pressure, and / or a spray-on layer) to act as a single textile. Laminates are most common in waterproof / breathable garments. Polartec NeoShell, Gore-Tex products, and The North Face Futurelight are all examples of laminates.
- Membrane: This is what makes a laminate waterproof. Membranes are typically non-textile (i.e., not knit or woven) materials that are designed to protect against water and wind. Membranes are often porous and / or air-permeable to increase breathability. Membranes are often made from PU, Polyester, or ePTFE.
- PU: Stands for polyurethane. PU is a common material used for waterproof breathable membranes.
- ePTFE: Stands for “expanded polytetrafluoroethylene.” This is the primary polymer component in Gore-Tex membranes. Different variations of this polymer are used in DWRs and in non-stick coatings for cookware (the common non-stick coating, Teflon, is made from polytetrafluoroethylene).
- Polyester: A synthetic polymer commonly used as the fiber in knit and woven textiles. Polyester is also sometimes used to make waterproof / breathable membranes.
- Face fabric: Refers to the outermost fabric layer in a laminate, or multi-density weave (e.g., a hard-faced fleece like the Patagonia R1 TechFace). In waterproof / breathable garments, the face fabric is used for durability against abrasion, it protects the membrane, and it is what the DWR coating (see below) is applied to.
- Fabric Weight (e.g., g/m2 or gsm): This is a measure of mass per area of fabric. Often measured in grams per square meter (g/m2 or gsm), this is a good metric for understanding how heavy a textile will be, and also often correlates with how thick the textile will be.
- Denier: A measure of the diameter of the individual fibers that make up a fabric. Generally, the higher the denier, the heavier and more durable the textile. However, the weave or knit and fiber material (e.g., polyester, nylon, cotton, etc.) also play roles in the durability, hand-feel, and other characteristics of a fabric.
- Yarn: A strand of individual fibers that are spun / twisted together to form a thicker, more resilient, cohesive string. Individual fibers are often extremely small and fragile, so mills spin those fibers into more substantial yarns that they then use to weave or knit a complete fabric.
- Warp & Weft: The two primary yarn components of a woven fabric. Warp yarns run longitudinally along the fabric, while weft yarns run perpendicular to the warp yarns. The warp and weft structure can be tweaked in the weaving process to create a huge variety of finished woven textiles.
- Backer: Refers to the thin interior material used in 3L and 2.5L laminates (see below) that sits against your skin. Sometimes called a liner or scrim, not to be confused with the hanging lining of a 2L garment. Backers protect the membrane in a laminate and are made of a vast variety of knit, woven, and nonwoven fabrics.
- DWR: Stands for “durable water repellent coating.” DWRs are typically applied to the face fabrics in 2L, 2.5L, and 3L shells (among other garments) to keep the face fabric from soaking through with water. The DWR is the component responsible for water beading up on the surface of fabrics.
Types of Laminates:
- 2-Layer (aka, 2L): A laminate using two layers, consisting of a face fabric and a membrane or coating. Despite the “2-layer” moniker, these garments are often constructed with an additional hanging (rather than laminated) liner to protect the membrane and provide better on-skin comfort.
- 2.5-Layer (aka, 2.5L): A laminate using two layers (face fabric + membrane) and a printed or laminated “½” layer for membrane protection and on-skin comfort. These laminates are often used on less-expensive and / or lightweight rainwear and often aren’t as comfortable or durable as 3L laminates.
- 3-Layer (aka, 3L): A laminate using three layers — a face fabric, a membrane or coating, and a backer. These garments tend to offer the best performance when it comes to durability, weather resistance, and breathability (though there are always exceptions), and consequently make up most of the high-end hardshell and softshell market.