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1st functional clothes (layer 1)
As a first layer and thus worn directly next to the skin comes functional underwear, shirts or pants. These items are made of various woven artificial fibres or mixes, with the common purpose of leading dampness (perspiration) away from the skin, but not to accumulate it as is the case with cotton. Artificial fibre clothes spread the moisture released over a greater surface area, so that it can evaporate considerably more quickly. On the basis of this characteristic there is hardly any cooling of the body through evaporation. This saves energy and increases the performance of the body. All functional clothes are antibacterial and most items have flat seams, to prevent unpleasant rubbing of the skin.
2nd insulation layer (layer 2)
Artificial fibres can be used here too. Most frequently fleece is used as the intermediary layer, with good insulation characteristics. Fleece is processed in the most varied shapes and forms, and therefore meets the most varied demands.
The feature common to all is that they offer similar advantages to functional clothing:
Rapid drying, low weight, insulation even in a damp condition, cosily soft, easy to look after and robust.
There are other "special forms" such as elastic (stretch) fleece, water-resistant fleece with extra features (DWR: Durable Water Repellency) and Bipolares Fleece where the inner and outer surfaces are prepared differently (inner soft and outer thicker and harder). The best-known producer is Malden Mills with its Polartec® fleece. There are now also other first-class products such as our Polarlite®. Using the Polartec® system from Malden, fleece materials can vary significantly. There are 100 gm (also called micro-fleece), 200 gm and 300 gm fleece. This relates to the weight per square metre.
Alternative insulation layers are items of clothing filled with down or artificial fibres, which are often able to store a great deal of warm air but can often be thicker, and this can mean they can be too warm for some purposes.
3rd wind and weather protection layer (layer 3 and 4)
This layer is the outer and therefore the most weather-affected layer of clothing according to the multi-layer principle. Even within the products in this layer there are various qualities. Depending upon the sort of use, windproof and watertight materials are used:
A. As for windproof clothing, we often find Windstopper® from the company Gore or comparable products such as Power Shield® from Malden Mills. These materials are characterised by the fact that they are up to 100 per cent windproof and thus prevent rapid cooling of the body through disruption to the warm air layer (wind chill effect). Other positive features of windproof materials can be the strong water-repellent effect (water-repellent but not 100% watertight!) (= Softshell), the relatively high breathability, the pleasant and often soft feel and the flexibility of use.
B. Alongside this there is watertight clothing. An item of clothing which is intended to be watertight, must also of course be watertight at its seams. So all seams are sealed on the inside with a seal strip. Basically, when it comes to watertight materials, a distinction must be drawn between "breathable" and "non-breathable" materials (such as Raintec®).
It must be noted here that the term "breathable" is in fact incorrect. It would be better to say: "moisture-permeable"! Moisture-permeability relies on the structure of membranes or layers. Moisture-permeable membranes and layers have pores or are micro-porous. These pores are so large that moisture can escape, but not sufficiently large for water droplets to penetrate from the outside.
In order to guarantee moisture-permeability, certain prerequisites must be fulfilled. A higher temperature must prevail inside the clothing than outside, because higher pressure is necessary. It can also occur in certain circumstances that a first-class GORE-TEX® membrane does not "function" as it might (the moist warm climate in the tropics is an example).
But even under optimum conditions, “breathability” can be restricted. At present the highest levels achieved are approximately 200 to 300 grams of moisture per hour per square metre. With many activities, however, more perspiration is produced: for example when walking, cycling or skiing, sweat can be produced at the rate of two litres an hour. In order to maintain a pleasant climate even under those circumstances, functional clothing and if necessary functional intermediate layers are necessary.
Endeavours are currently being made to obtain a uniform value for the moisture-permeability of a material. The RET (Resistance to Evaporating Heat Transfer) value ignores the resistance of a material in manufactured clothing (not only the membranes) to moisture penetration. There are various opportunities to promote moisture-permeability, such as underarm zips and pocket ventilation.
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