For quite a long time, field workers such as geologists in synthetics Kolyma and Chukotka fundamentally disregarded any synthetic materials in their expedition equipment.
Even those among them who were not strangers to mountain tourism and mountaineering in their free time exchanged their modern anoraks for cotton clothes when going out to the field. There are several reasons for this, but the main one is that synthetic materials are not fire-resistant.
Nevertheless, clothing made from synthetic fabrics now dominates both storefronts and the shoulders of travelers all around the world.
That’s why, whether you want it or not, we will need to discuss contemporary synthetic clothing (more precisely, its combinations).
The fact is that modern clothing made from high-tech synthetic fabrics practically does not exist “on its own”. A wool sweater worn over thermal underwear effectively reduces the efficiency of the former by at least half. Similarly, a Polartec sweater worn over a cotton t-shirt loses its moisture-wicking function, as the t-shirt underneath remains wet anyway. That’s why it’s necessary to focus not so much on the flashy names of materials that are filled with labels of modern tourist and expedition clothing, but on the general principles that unite these garments.
There are two principles: retaining air in a special structure of textile fibers and removing excess moisture from the body outward. Following the first principle provides warmth, and the second provides dryness.
The first layer of clothing on our body is underwear. In this case, thermal underwear.
Thermal Underwear from www.huntingshopfavia.com
Thermal underwear is available in two variants – heat-retaining and moisture-wicking.
Heat-retaining underwear, as requested by its manufacturers, is intended for a calm sedentary life in cold weather. Let’s translate the phrase from the traveler’s brochure language: it should be comfortable to sleep in such underwear. Because sleep is the only thing the traveler does when not working intensively. Heat-retaining underwear contains a significant amount of air due to its cellular structure and the fact that fine synthetic threads are included in the fabric. We will discuss similar materials when talking about sleeping bags, but for now, that’s enough.
Moisture-wicking thermal underwear has the ability to remove excess moisture (i.e., sweat) from the surface of the skin. Usually, this type of thermal underwear is made entirely from synthetic fabric. The most well-known of these are Coolmax, QuickDry, Thermolite Base, Polypropylene, Viloft, and many others.
The principle of action of thermal underwear, like all other moisture-resistant fabrics, always remains the same: there is air between the skin and the fabric and within the fabric itself, which is heated by the body. In this way, a zone of warm air appears between the skin and the fabric. As the air is heated, it expands, creating a zone of high pressure. The ambient temperature is lower, i.e., there is a zone of low pressure. Thus, the warm air, heated by the skin, penetrates through the fabric outward, simultaneously carrying away evaporating sweat molecules. This is how we achieve the effect of moisture removal. Remember that we are talking about synthetics, which is usually a hydrophobic material, i.e., it does not structurally absorb moisture itself, unlike natural fabrics. In other words, with functional thermal underwear, we achieve improved moisture resistance, a significant reduction in wetting, which in turn leads to noticeably accelerated drying of the fabric.
Polartec and Similar Materials
Polartec is a type of fabric that imitates the properties of sheep’s woolen fabric (by the way, sheep’s wool is fleece), and Polartec and its variants (Classic, Power Dry, Power Stretch, Thermal Pro, Power Shield, Windbloc, Aqua Shell), similar to Polarfleece, are registered trademarks owned by Malden Mills. Most of us are familiar with this soft, fluffy fabric, which Time magazine attributes to the 100 greatest things of the 20th century.
Overall, Polartec is positioned as a material that is several times better in thermal insulation than woolen fabric, while also being lighter in weight and more moisture-wicking. Personally, during my travels, I have used two Polartec Thermal Pro anoraks with varying success. And, as usual, I used them with my usual skepticism, meaning I paired them with a full-fledged diving suit pullover. I must say, I didn’t notice fundamental differences between Polartec and wool in terms of thermal insulation. But! At the same time, the Polartec jacket weighs three times less than a sweater. And most importantly, how quickly it dried!
Even when it gets damp, this garment can dry under an outer layer, worn over bare skin. The same fact speaks to its qualities as a moisture-wicking tool. During the shoulder season, characterized by temperature fluctuations from -10 to +15 degrees Celsius at different times of the day, this material can be considered quite effective. And as I mentioned, Polartec is much lighter than an equivalent wool product in terms of thermal insulation.
Furthermore, this jacket dries even in the slightest breeze.
I must say, fabrics like Polartec and GORE-TEX have amazed me, an ordinary traveler from the Far East, with the many interesting technical solutions they contain. It means that materials grouped under the name Polartec (and there are actually many of them – Polartec 200, Power Stretch, Thermal Pro, Windbloc, Windbloc ACT, Wind Pro, and completely different names if you’re searching), have a microcapillary fiber structure, and the fibers facing the body are not the same as the fibers facing outward. They use specialized weaving techniques, and some of them are treated with special water-repellent compounds. There’s a wind-resistant material called Windbloc, which was mentioned earlier – it competes with the complex GORE-TEX. It’s such a world of high technology that we only dreamt of during the period of reading science fiction novels about the conquest of Mars and Alpha Centauri!
In addition to the Polartec anorak, my wardrobe also includes gloves made from this material. And all for the same reasons – lightweight and completely dry.
In any case, I recommend having a very lightweight and compact (rolled up) Polartec sweater or jacket in your camping wardrobe. It should be carried in a waterproof nylon bag in the most accessible pocket of your backpack.
You can wash Polartec products with regular soap, in warm water at a temperature not exceeding 40°C, either by hand or in a washing machine with a light load, in a gentle synthetic washing cycle. Polartec clothing will last longer when washed with special mild detergents (e.g., Nikwax Tech Wash) and then rinsed with a water-repellent solution (e.g., Nikwax Polar Proof). Polartec products should not be ironed and should not be dried at high temperatures.
The original GORE-TEX is another interesting material based on the principle of “let everything out, don’t let anything in,” meaning it’s a waterproof and breathable material produced by W.L. Gore & Associates. To be truthful, GORE-TEX, like Polartec, has many analogs and quite a few counterfeits. Classic GORE-TEX is a three-layer material consisting of an outer fabric, a thin fluoroplastic membrane film, and an inner lining fabric.
The main high-tech secret is precisely this fluoroplastic membrane, which has a tremendous number of pores per unit area. It contains 1.5 billion microscopic pores per square centimeter, while the size of the pores is 20,000 times smaller than a water droplet, which prevents water from passing through the membrane. At the same time, the size of the pores is 700 times larger than water molecules (water vapor), achieved through ventilation. The tunnel-like structure of the pores breaks down the air stream into microvortices and acts as a barrier to the wind, without obstructing the individual water vapor molecules.
The manufacturing company claims that these pores are so small that they don’t clog with dirt, but practice shows that after spending several nights in a GORE-TEX suit near a fire, it may not be clogged with dirt, but it will certainly be clogged with smoke particles.
In principle, as part of an overall system, when moisture from the body is first removed through thermal underwear, then transferred to the Polartec jacket and released through GORE-TEX, GORE-TEX products work best at moderate external temperatures – low “plus” or slight “minus.” At really low temperatures, it freezes from the inside (it’s clear why – the pores are clogged with ice), and at really high temperatures, it needs to function as a return pump – to pump moisture out of the air under the jacket. There’s a special GORE-TEX version for the jungle.
A significant drawback of GORE-TEX as a clothing material for a traveler, in my opinion, is its demanding requirement for external treatment with special compounds, as well as the fact that it can still get wet in prolonged rain. Therefore, for me, these are clothes for a short hunting trip or a weekend route. For a truly serious journey, I continue to take a canvas jacket…
Overall, depending on the extent of their widespread use, synthetic fabric clothing can be divided into two categories – one that can be categorically recommended as an alternative to the traditional approach – thermal underwear and Polartec products, and for outerwear, GORE-TEX. However… Where is the guarantee that at the time of writing these lines, some company is not testing a new high-tech material?