Outdoor Clothing Fabrics Explained
4 October 2010
We get lots of questions about the different types of fabrics used on the outdoor clothing that we sell, so here's my effort to explain a few of the fabrics. It's not a very big list to begin with but I'll keep adding to it.
Everyone knows about Gore-Tex but we might as well start with the most popular terms. Gore-Tex is expanded polytetrafluoroethylene (ePTFE). On the outside the pores in the membrane are 20,000 times smaller than a drop of water, so external moisture can't get through. On the inside the pores in the Gore-tex membrane are 700 times bigger than a water vapour molecule, so water vapour from your sweaty pits can easily get though. To protect the pores from your sweat and dirt (sorry, I'm not saying you're stinky
really), there is also a thin layer of polyurethane (PU) bonded to the inside of the membrane.
Click here for a bit more information about Gore-Tex
Event fabric again uses a ePTFE membrane but this time it doesn't use a second layer of polyurethane as protection. eVENT argue that this extra layer makes the breathability process inefficient because it takes two separate processes to get the sweat out. eVENT have a patented surface protection system that maintains the breathability without the need of another polyurethane surface to protect it from clogging up. In test eVENT has proven to breath at lower temperatures than Gore-Tex, so it starts to get rid of sweat as soon as you body begins to heat up inside your jacket.
|Omni Tech and Helly Tech|
These are also waterproof laminates which are bonded to the nylon outer of the jacket. They have various degrees of waterproofing and breathability depending on how much you want to pay.
|Just a quick note about 2 and 3 Layer Jackets|
Most technical jackets have three layers:
Outer layer - usually nylon with a coating on top to allow the water to bead. This is DWR finish or durable water repellant finish. This DWR finish is the thing that needs to be Nikwax regularly so stop the nylon outer of the jacket absorbing water.
Membrane layer - Gore-Tex, Event, Omni-Tech, Helly Tech etc. The membrane is stuck onto the outer membrane or bonded with the outer fabric.
Inner layer - protects the membrane and catches the water vapour to help push it through the fabric. This can be a hanging free layer or bonded to the inside of the jacket
2 Layer jackets - These jacket usually skip the membrane and just have a PU nylon outer treated with a DWR finish and a mesh lining to help force the sweat out.
PU is a polymer with urethane links that according to Wikipedia can be used for just about anything. Because my chemistry teacher wore a wig this prevented me from paying attention and so if you want to know about PU then you will have to Google it.
More Chemistry - Nylon is part of the polyamides family, they use the amide groups in their molecular backbone and I'm happy for them. For our outdoor purposes Nylon is extremely durable with a high tear resistance and generally lighter than polyester and importantly not as whiffy. It is used extensively for the outside of jackets because it bonds well with the ePTFE membranes.
This is the original fleece manufactured by Polartec in 1985. The 100% polyester velour construction creates air pockets that trap air and retain body heat. Comes in different weights 100, 200, 300 depending on how warm you want to be.
Polartec offers 300 different fabrics and since I can't be bother going through the lot we'll keep it simple. Polartec's catchphrase is 'Warmth without weight' and all their products will keep you toasty, are highly breathable and dry quickly. Here's a few of the of the different polartec options:
|Polartec Power Dry|
This has a bi-component knit construction which means there are two fabric on either side - one moves moisture the other dries quickly. Power Dry move 30% more moisture than single component fabrics.
|Polartec Thermal Pro|
100% polyester but this time with pebbled or shearling (looks like sheepskin) surfaces to create air pocket that trap air and retains body heat. The unique surfaces also provide some fancy styling options, so you can still keep it real on the street.
|Polartec Wind pro|
Four times more wind resistance than normal fleece while maintaining 85% of breathability. Very tight yarn construction on the outer surface prevents that chilly wind getting in.
Pertex has been around since 1970 when Hamish Hamilton went to Perseverance Mills and started banging on about capillary action and how it could be applied to synthetic fabrics. Instead of throwing him back out on the street, they developed the product. A beautiful story, I think you'll agree. There are a few different varieties to get though.
Click here if you want to amaze your thick friends...
Made from Nylon Yarns and uses Hamish's concept of capillary action to move moisture away from the body while offering excellent moisture protection. Just a brief note on capillary action: this is where the moisture moves along the capillaries between the micro fibres and spreads over a large surface where it evaporates quickly.
This makes them very breathable and wind resistant. Pertex Classic has maximum abrasion resistance and tear resistance of all Pertex products but it is the heaviest of all the products.
Has a unique denier gradient structure which moves the moisture away from the skin more effectively, combining two different yarns with different properties. On the inside a yarn with larger filament and on the outside a yarn with smaller filaments. Moisture moves quickly from the larger filament to the smaller filament.
The lightest Pertex fabrics using the finest yarns with the maximum thread count. Quantum has very good tear and seam strength for the weight and a 25% - 50% weight reduction. Abrasion resistance is not quite as good as classic pertex.
Microlight uses the softest and lightest fabrics. It is made from tightly woven micro fibre yarns and the dense weave reduces heat loss. Used in insulated jackets.
Microporous polyurethane (PU) coating with a Dry technology finish. From what I can gather it is a bi-component technology 'combining two opposites without compromise' - I like that. This prevents water from escaping and allows sweat to get out. The waterproof finish is not a coating it is applied to every fibre to eliminate stiffness and have better air permeability. There is no membrane which makes these jackets very lightweight without losing a vast amount of breathability.
The patented PrimaLoft ultra-fine microfibers are specially treated in a proprietary process, creating a core with incredible insulation properties. PrimaLoft is as warm as down, compressible, breathable and offers superior water repellency so you remain dry, warm and comfortable even under the most extreme conditions.
PrimaLoft® Eco is earth-friendly insulation created for performance and comfort. Eco insulation technology combines 50% recycled material with PrimaLoft virgin fibers to create a high loft, thermally efficient insulation. PrimaLoft Eco is lightweight and water resistant with superior softness to keep you dry and comfortable. It's global warming the right way!
Other forms of synthetic insulation:
Constructed using high tenacity fibre technologies, ounce for ounce, CORDURA® fabrics are more durable than comparable unbranded fabrics
Ultra Light Weight Nylon Ripstop Fabrics (30, 70, 100 denier) are used extensively in outdoor clothing.
Type of nylon which has a cotton feel and is lightweight and breathable, it is also very tough.
More chemistry to end on a clever note: Polyester is a manufactured product made from synthesized polymers with hydrocarbon backbones but let's just say it's a fancy plastic. It tends to be very resilient, quick drying, resistant to biological damage such as mold and mildew, easy to wash, and able to hold forms well. The majority of wicking tees are polyester. Its only problem is it stinks a bit. Manufacturers usually add polyester to other natural fibres to get rid of the stench - it doesn't work though.