Thermal underwear is underwear (T-shirts, shirts, pants, underpants, socks) made of synthetic fabrics, sometimes with the addition of natural ones. Thermal underwear should have the following parameters:
- The removal of moisture (sweat) from the surface of the skin.
- Thermoregulation (heat preservation, but also prevention of overheating).
- Convenience in all modes of activity (should remain soft and dry).
- Preservation of body hygiene for a long time, eliminating the appearance of a smell of sweat.
For the manufacture of thermal underwear, manufacturers use synthetic materials, in particular polyester, which has a "cellular" structure, but in general underwear is multilayer. In this case, the upper one works on evaporation, and the inner layer removes moisture from the body. Thus, the body is not moisturized and not cooled. "Cells" also hold air, which provides additional thermal insulation. It is important to note that thermal underwear neutralizes the irritating effect of sweat on the skin. This happens for two reasons: firstly, the contact time of sweat with the skin is reduced, and secondly, manufacturers treat high-quality thermal underwear with special antibacterial compounds that do not lose their properties even with a certain number of washings.
Thermal underwear is single-layer, double-layer, fleece, stretch, etc. You need to choose the size so that the linen fits tightly around the body, otherwise moisture will simply not be removed from the surface of the skin.
Again, for high-quality products, flat seams and double cuffs contribute to a more dense, comfortable fit of the laundry and prevent rubbing.
Cotton - faster than other materials, it removes moisture from the skin, even without tightly touching it, it accumulates moisture and holds it very firmly. But the retained moisture cools the body, and therefore cotton is usually used in combination with synthetics, which allows moisture to be removed faster and the skin remains dry. Linen made of 100% cotton is recommended for everyday wear, light walks without any stress. It retains heat much better than synthetics. In hot weather, trapped moisture cools the body.
Wool - wool fibers have a protein composition, which allows them to chemically bind water. Wool can bind an amount of moisture equal to 1/3 of its own weight, while remaining warm and dry to the touch. As a rule, wool of “merino” sheep breeds, which is soft and light, is used for linen. The heat-preserving and warming properties of wool are indispensable for prolonged exposure to cold.
Silk - gives linen more wear resistance, strength and smoothness. Silk underwear is pleasant to the skin.
Synthetic thermal underwear meets all the necessary requirements for it - removes moisture from the skin, regulates heat transfer, preserves body hygiene, it is comfortable with all modes of activity.
Synthetics removes, but does not accumulate moisture, linen is more wear-resistant, less prone to deformation. Does not stimulate the growth of sweat-causing bacteria. In addition, manufacturers use special impregnations to increase the antibacterial and antimicrobial properties of linen.
The main materials:
Polypropylene (PP) - better than other materials, it removes moisture from the skin without getting wet, therefore it is often used in fabrics of linen used for high activity. But it dries the skin and such underwear is not recommended to be worn for a long time, much less sleep in it. Not very durable, has a fragile structure. It melts at relatively low temperatures, so you can’t dry near heating appliances, even sit close to the fire.
Polyester (PES) - The fiber structure is similar to regular cotton. Linen made of polyester lasts a long time, removes moisture well, and remains soft. Can be dried on a battery and even ironed. The most famous brands of this material for thermal underwear are coolmax (DuPont), power stretch (Malden Mills).
Polyamide (RA) - linen is light and smooth to the touch. Almost all seamless underwear is made of polyamide. Well-known developments are Tactel, Supplex (DuPont).
Elastane - used as additives - to increase the wear resistance and elasticity, the thinnest elastane fibers are added to the composition of thermal underwear. The higher the% elastane, the better the laundry stretches without deforming. The most famous elastane is Lycra (DuPont).
All heaters retain heat thanks to the air that lingers between its fibers. The more air held, the better the insulation. The more fibers in a small volume of insulation, the more air layers are formed. The insulation can be either a separate product (fleece jacket for example) or a part of insulated clothing in the form of a down or synthetic filler.
- Conservation of heat.
- Condensate drainage from thermal underwear to the outer layer.
- Stay dry and do not absorb moisture.
- Light weight.
- Durability and ease of care.
- Preservation of all properties after repeated washing.
Fleece - the name comes from the English word "fleece" - wool, pile, fleece. Fleece is a knitted fabric with a polyester pile.
Fleece - very soft to the touch and fleecy material. It happens one-sided and two-sided. Wear-resistant, lightweight, quick-drying. Perfectly “breathes” and retains heat. Heat is maintained thanks to the air held between the villi. The usual composition is 100% polyester, but there may be cotton or wool additives. The most famous brand of fleece is Polartec (Malden Mills).
Polartec is the name of a series of materials, but in any case it is the best fleece. The polyester pile is more densely located on the knitted fabric, and the fibers themselves have a hollow structure. The ability to retain heat is not inferior to wool, but softer and does not get wet from the body's fumes. The clothes from it are beautiful, comfortable, do not wrinkle, are easily washed and dry quickly.
Briefly about Polartec fabrics:
Polartec 100 - short-fleece fleece, 100% polyester, used in the manufacture of thermal underwear and lightweight insulation.
Polartec 200 - medium-fleece fleece, 100% polyester, soft, light. It has excellent thermal insulation properties. In terms of thermal properties per 1 gram of material, it is twice as much as sheep’s wool and more than three times as cotton. Thicker and denser than Polartec 100, excellent insulation.
Polartec 300 is even thicker and denser than Polartec 200, 100% polyester, mainly used for outerwear.
Polartec Power Stretch is a thin and flexible material with very high “breathable” properties, used for thermal underwear. Upon contact with the skin, removes excess moisture and leaves the skin dry. Moisture-removing properties are 25% higher than other materials used for thermal underwear. The fiber consists of two layers - a durable smooth outer nylon layer and a soft inner layer with a pile of 100% polyester.
Polartec Termal Pro is a lightweight, warm, moisture repellent material. It has an abrasion-resistant outer surface, protects against wind and light rain, a soft fleecy inner layer provides maximum thermal insulation. In this case, moisture vapor from the body is freely removed to the outside. Very durable and dries quickly. Unlike many fleecy fabrics, it retains its properties and does not roll after repeated washing. Outer and inner fleecy layers of polyester and polyester fibers.
Polartec Windbloc is a breathable, warm, windproof material. Provides 100% protection at wind speeds up to 50 km / h. The wind blocks the membrane, which is located between two layers of fleece. The use of this material more than halves the number of insulating layers. Clothing can be used as a top wind and snow protection, as a heater.
Polartec Windbloc ACT - has all the advantages of Windbloc fabric, and in addition has additional protection against mechanical damage. Composition - the outer fleecy layer, then the membrane and the mesh inner lining fused with the membrane. This fabric is thinner and softer than regular Windbloc. Thanks to AST technology (Air Control Technology), the ability of the material to remove moisture into the environment is 3 times higher than that of other types of windproof fleece. Clothing can be used as a top wind and snow protection, as a heater.
The main parameter by which fluff is evaluated is its elasticity, determined by the Fill Power or F.P. and fluff / feather content.
Fill power. - This is an indicator of how well fluff is compressed in volume.
FP = V (free) / V (compressed), [Cuin]
where V (liberty) - one ounce of fluff (28.35 g) in a free state, in a glass flask 1 liter.
V (compressed) - in the same place, but already compressed.
Ways to place fluff in products
A single-layer down bag - has cold through seams, sometimes a protective layer of fabric is used or without it. It is used for the production of urban and ski products. The disadvantage is cold through seams. Advantages - durability, low weight, easy to repair and care.
A two-layer down bag - may also have a protective layer of fabric. It is used for tailoring expeditionary and warm climbing clothes made of fluff. The disadvantage is more complex production, which affects the price. Advantages - has no through seams - the warmest version of down products.
A single-layer bag with partitions - for the production of simpler hiking and climbing clothes. Advantage is the easiest of the options for warm products. The disadvantage is that it is practically impossible to repair.
Synthetic heaters do not have the disadvantages of natural ones: they dry faster, practically do not absorb moisture, easily compress and restore their shape. At the same time, their heat-shielding properties closely approach downy ones. Today there are a large number of synthetic heaters developed by well-known companies: Polarguard, Thermolite, Thinsulate, Quallofil, etc. Mostly they are based on the interweaving of hollow fibers of polymeric materials. But in terms of heat-saving ability / weight, brand-name synthetic heaters differ from non-name very much, as well as in price. The service life of nameless heaters is much shorter than famous ones.
Of course, it is not the insulation that warms, but the air between the insulation fibers. The greater the thickness of the air gap, the more efficient is the heat storage.
Internal cavities affect weight, and not its thermal conductivity, since the volume of air inside the fiber is very small compared to the total volume of the air gap.
Heat insulation from DuPont
Hollofil-II is a thick fiber having four longitudinal holes.
Thermolite plus - a mixture of very thin fibers and medium fibers with one longitudinal hole
Thermolite extra is an ordered spiral-shaped medium fibers that are hollow inside.
Thermolite extreme is a mixture of microfibres of three different types, each of which gives the material certain properties - strength, elasticity, and the ability to retain heat. Internal cavities affect weight (i.e., for example, a sleeping bag weighs less), and partitions work like stiffening ribs and give elasticity to the fibers. The first synthetic fibers had thick walls. Today they strive to make the walls thinner, but at the same time the fiber should not become brittle. For this, the fiber is treated with silicone.
The 3M company produces a good insulation under the Thinsulate brand. He appeared with us not so long ago, but has long been known abroad (20 years). The structure of the fibers of this insulation approaches the structure of natural fluff (due to the presence of thin (2-5 microns) polyester and polyolefin fibers), and therefore it has excellent thermal insulation properties. It is produced in several versions, which differ in different specific gravity and purpose. It retains its thermal insulation properties when wet and dries very quickly.
The finest polyester fiber, trihedral in cross section and hollow inside. It compresses well after compression and has the best thermal insulation properties in the line of synthetic heaters. The most wear resistant. It recovers perfectly after compression. Keeps the heat-insulating properties when wet.
Polarguard 3D - Thick Hollow Fiber
The company Albany International produces insulation under the brand PrimaLoft
Microfiber synthetic insulation. Holds a large amount of air in a small volume. It is light weight.
Of all the brands, only PrimaLoft has the ability to not retain moisture due to the silicone processing of the fibers. As the table shows, the greater the number of fibers, the more insulation collects moisture:
PrimaLoft PL1 - 75%
PrimaLoft Sport - 400%
Polarguard 3D - 500%
Thinsulate LiteLoft - 995%
MicroLoft (DuPont) -1730%
The material is "thermoregulating." This material is patented by the American company Outlast Technologies, which was the first to start the development of thermostatic technology. The main feature of Outlast is to maintain a constant body temperature, regardless of the degree of motor activity and external temperature. The material includes a huge number of microcapsules filled with a substance (paraffin), which can quickly switch from a solid state to a liquid state and vice versa, and thus accumulate or give off heat. With increasing temperature, Outlast absorbs excessive heat, preventing the body from overheating, while lowering the temperature, heat is transferred back, preventing overcooling. Thus, Outlast maintains a constant temperature balance inside the garment.
1. Excessive heat of your body is absorbed by Outlast tissue capsules, preventing overheating
2. Heat is evenly distributed over the Outlast layer, eliminating the occurrence of local overheating or hypothermia zones
3. The stored heat is released when the body temperature decreases, maintaining optimal thermal balance.
3. PROTECTIVE LAYER
- removal of moisture from linen and insulation in the external environment
- protection against water and snow.
- Protection against cold air, wind resistance
- Special cut does not constrain freedom of movement
- high strength
- light weight
- Long service life
- Preservation of all properties after repeated washing
At the same time, “breathing” and protection against precipitation, as well as wind resistance, are provided by membrane tissues. Depending on the type of fabric, it can be durable or very light. To increase the service life of membrane clothing, make inserts of high strength materials in places subject to the greatest wear.
Membrane tissues, which are part of the outer layer (located under the upper main tissue), remove fumes to the outside, do not pass water and wind.
Moisture resistance - measured in mm. water column, which means the height of the pressure of the water column on the fabric at which it still does not pass water, i.e. does not get wet.
Less than 1000 mm - just wind protection.
1000-2000 mm - drizzle, fog with a slight wind.
2000-4000 mm - light or drizzle with wind.
4000-7000 mm - prolonged drizzle, short, up to 1 hour rainfall with a strong gusty wind.
More than 7000 mm - heavy rains, prolonged downpours with strong gusts of wind.
More than 10,000 mm - a storm with strong wind and rain.
Vapor permeability (“respiration”) - is measured in g / m2 per day, which means the weight of the total volume of steam passing through 1 m2 of tissue per day.
Less than 2000 - virtually no “breathing”
2000-4000 - easy walks
4000-8000 - active games, sports
more than 8000 - extreme physical activity.
What is the breath rate Ret
The respiration rate is the “respiration” coefficient that measures the ability of a material as a barrier to evaporation of sweat from the surface of the body. The lower it is, the better the material allows the body to “breathe”. Evaporation resistance occurs approximately like this - in a material, one side of which is in contact with dry air, and the other with moist (for example, from the body) air exchange process occurs. In order for the vapors to come out, it is necessary that the humidity and temperature of the air around the body are higher than the environment. The larger this difference, the higher the air exchange. Index Ret <60 - comfort under high loads (running, difficult lifting). At medium loads, the indicator 60-130 is comfortable. From 130 to 200 is better not to move - you sweat. More than 300 - the fabric does not “breathe”.
Membrane Tissue Classification
Three-layer - top fabric + membrane + lining glued into one structure using a special technology - lamination. It looks like a fabric with a fine mesh from the inside. The inside of the knitted mesh protects the membrane from clogging and mechanical damage. Well, and accordingly do not need a lining. As a result, we get a very light, maximally functional fabric with a small volume.
Two-layer - top fabric with a membrane applied. Used with a lining that protects against clogging and mechanical damage.
Two-and-a-half layer - a two-layer membrane with the additional application of a foamed protective layer (in the form of pimples). The jacket turns out to be as light as possible - no lining is needed and the protection weight is much less than that of three-layer materials.
Monolayer - a freely located membrane between the outer layer and the lining. Used in accessories and shoes.
Pore - membranes work according to the following principle - water droplets entering from the outside cannot pass through the pores of the membrane, since these pores are too small. The vapor molecules formed from the inside of the membrane tissue freely pass through the pores to the outside (since the vapor molecule is thousands of times smaller than the water molecule).
The advantages of such membranes are that they "quickly" begin to breathe, i.e. remove vapors.
Disadvantages - they quickly lose their properties, as the pores become clogged and breathing properties decrease. If improperly washed, the jacket may leak
Non-porous - do not have pores and work according to the following principle - fumes reach the inner part of the membrane, settle on it and, with the help of active diffusion, quickly transfer to the outer layer (they are transferred via a conveyor from the inner layer to the outer one).
Advantages - very durable, do not require careful care, work properly in a wide temperature range.
Disadvantages - since “breathing” begins to be “slower” than the pore membranes, it may initially seem that the product is getting wet - these are the vapors that accumulate on the inner layer.
Combined - the top fabric is covered on the inside with a pore membrane, on top of it there is a thin coating with a non-porous polyurethane membrane film.
It has all the advantages of both types of membranes, avoiding their disadvantages.
The disadvantage is the price !!!
Microporous Membrane Tissues
Microporous membrane tissues, as the name implies, have a microporous structure. Pores are many times larger than a water molecule and many times smaller than the smallest drop of water. How optimally the pore size is matched, the characteristics of the microporous membrane tissue are so high. It is very difficult for manufacturing companies to do this. High characteristics of the membrane depend on the quality and chemical composition of the polymer, special technological developments and sufficient experience with the manufacturer in this area.
Gore-Tex® fabrics (Gortex) are some of the most wear-resistant, water-repellent, windproof, breathable fabrics. The fabric consists of two components. The first is the PTFE (polytetrafluoroethylene) membrane, which does not pass water; it contains 9 billion pores per square inch (2.54 cm2). Each pore is 20,000 less than a drop of water, but 700 times more than a vapor molecule. As a result, water in a liquid state does not penetrate through the tissue, but the vapor released by the body freely passes out. Gore-Tex® provides essential breathing, moisture resistance and durability at the same time. Respiratory rates 12,000 g / m2 per day, moisture resistance 30,000 mm, wear resistance - 200 hours of continuous washing.
Until recently, W.L. Gore & Associates was the only company that had a registered right to use PTFE membrane fabric material.
PTFE is a polymer manufactured by DuPont. PTFE's DuPont itself offers Teflon.
Gore-Tex® Paclite® is the thinnest membrane in the Gore family. Respiratory rates Ret <40, water resistance> 30,000 mm. The membrane is used unlined. A special carbon coating is applied on top of it.
Gore-Tex®XCR is the latest modification of the Gore-Tex membrane. More wear-resistant, has a complex multilayer structure. Breathes 25% better than regular GTX.
Gore-Tex®XCR Stretch - the stretchable membrane combined with a stretch top for the best fit, does not constrain movements. It may be an example of soft clothing.
Gore-Tex®Wind Stopper® is a windproof fabric - fabric with a welded membrane
Gore-Tex®. Provides complete wind protection with a strong breathing effect. In cold windy weather, Wind Stopper® products provide heat retention 1.5 to 2 times better than regular fleece fabrics. Wind Stopper® makes it possible to use fewer layers of clothing to retain heat, and, as a result, greater freedom of movement. Wind Stopper® is extremely durable - after 100 washings, its qualities are not lost.
Wind Stopper® breathability is less than 30 cm3 / min / m2 (windproof materials such as microfiber, Nylon Taffeta, Supplex have indicators from 90 to 750 cm3 / min / m2). Wind Stopper® is lighter than Windblock, but Windblock is warmer than Wind Stopper®.
Gore-Tex®XCR Snow - between the inner lining and the upper material with a laminated membrane, there is a layer of insulation.
eVENT (event) is an “active” membrane. The German company Vaude and the American manufacturer of BHA membranes have teamed up and implemented the eVENT membrane. eVENT is a water-repellent microporous membrane PTFE material that provides good breathability. The membrane also works without a difference between the outside temperature and the temperature inside the garment.
TransActive absorbs and removes moisture through eVENT.
Indicators of "respiration" over 20,000 g / m2 per day, water resistance of about 70,000 mm.
The membrane was developed by BHA and complemented by the TransActive Rapid Moisture Removal System, a technology developed by VauDe.
VNA and VauDe give a lifetime guarantee на eVENT.
If Gore-Tex is an independent microporous membrane, then all other microporous membranes are polyurethane coatings on the inner side of external tissues and do not exist separately from them. They are also called microporous laminate.
There are a lot of such membranes on the market. As a rule, their names end in the syllable –tex. For example Salewa - Powertex (powertex). They differ in respiration, moisture resistance, weight, etc.
Non-microporous (non-porous, continuous hydrophilic) membrane tissues
Non-microporous membrane tissues have a special chemical polymer structure. They breathe well, do not get wet and protect from the wind.
These membranes have a number of remarkable qualities: clothes with them can be washed with almost any detergent in the normal mode of the washing machine, dry cleaning is acceptable, they have the ability to stretch strongly in all directions without residual effects, and can be laminated (applied) to any type of fabric.
The work of non-microporous membrane tissues is based on a combination of the properties of a water vapor dipole and the free bonds of the membrane polymer (the inner column of the membrane is hydrophilic, the external is hydrophobic).
Dermizax. The most famous non-microporous membrane fabric is Dermizax (dermizax) manufactured by the Japanese concern Toray.
Ø respiration of 18,000 g / m2 in 24 hours;
Ø water resistance> 20 000 mm;
Ø elasticity up to 200% elongation;
SympaTex (sympathex) is one of the first non-microporous membranes that has proven itself in the sports market.
Ø SympaTex professional - breath of 15 000 g / m2 in 24 hours, thickness 0.4 mm;
Ø Water resistant over 27,000 mm water column