The prerequisite for winter boots is that they keep your feet warm and consist of water resistant material. A high-quality sole ensures good comfort when walking in the snow. The outer sole must therefore have anti-slip and thermal insulation (to isolate the cold from the ground).
Various materials and technologies are used for the thermal insulation of shoes, including:
- Polartec - quickly after the introduction of Polartec, the material became a big hit in the market with thermo- insulating clothing and shoes. The Polartec insulation provides the same heat as comparable fabrics, but it also requires much less volume and weight. In addition, the material is breathable, allowing evaporation from perspiration, fast drying, surpassing other fleece fabrics in terms of durability.
- Thinsulate - has been on the market for over 25 years. The Thinsulate insulating layer is thin, light and warm. Precisely the strength of the insulating layer plays an important role in terms of heat in shoes. To put it simply, there is no room for something massive in the shoe. And this also applies to warmth. The feet are far from the "heat source of the body", so are all the more dependent on good heat insulation. Thinsulate ™ is almost twice as warm as foam, nonwoven, or current fabric, and is one of the lightest synthetic thermal insulation on the market.
In order to ensure waterproofness of the shoes, membranes or protective sprays are used. Protective sprays must be renewed after 2-3 months, as they lose their function over time. Also shoes with membrane should be coated with protective sprays, because the material is much more stressed in shoes than in clothing and the coating helps to prolong the life of the membrane.
Most common membranes in winter boots
- Gore-Tex membrane - a thin, microporous film with billions of microscopic pores on squares. The pores are much smaller than water drops, so the membrane is tight against liquid water, but sweat is passed as water vapor. Your feet remain dry and the foot climate is always optimal.
- SympaTex membrane - unlike Gore-Tex, the membrane does not contain any pores. The material base consists of a copolymer consisting of 70% polyester and 30% hydrophilic polyethylene. The membrane is about 5 micrometers thin and with an extensibility up to 300% it provides excellent movement. However, the permeability of perspiration is only ensured to a maximum temperature (about 15 degrees). The advantage of this membrane is the long service life. Since it contains no pores, these cannot be clogged, which can occur after long-term use in porous membranes.
- Omni-Tech Membrane - a development of the Columbia Sportswear Company, which similar to other membranes, combines water tightness and respiratory activity. These materials are bonded to the outer material and/or inner lining (laminated) to meet the requirements in the respective application area.