Breathable fabrics

High-performance breathable fabrics (e.g., GORE-TEX), ski waxes, waterproofing... 

B. Material The cover can be made from any fine weave cotton/polyester, or the new breathable fabric called Gortex , which allows water vapor, "perspiration", to pass through the material fibers without retaining moisture itself.Dimensions of the cover are greater than the pad to allow for flex and expansion.The finished pad/cover unit should be about ll"xl3",or 1/2" wider on each side of pad.The seams can be made by machine or hand.The final seam may be done as a chain stitch to allow for easier removal of pad when cleaning cover. 

Sustained military operations at MOPP-4 are unlikely owing to heat and respiratory loads and the inability to perform fine-motor functions at this level. This will remain the case for some time. Efforts to develop improved, semiper-meable breathable fabrics are unlikely to yield new, widely fielded garments for a number of years. 

Moreover, the term "breathable" implies that the fabric is actively ventilated. This is not the case. Breathable fabrics passively allow water vapour to diffuse through them yet still prevent the penetration of liquid water. Production of water vapour by the skin is essential for maintenance of body temperature. The normal body core temperature is 37°C, and skin temperature is between 33 and 35°C, depending on conditions. If the core temperature goes beyond critical limits of about 24°C and 45°C then death results. The narrower limits of 34°C and 42°C can cause adverse effects such as disorientation and convulsions. If the sufferer is engaged in a hazardous pastime or occupation then this could have disastrous consequences. 

PVC plastisols and latexes are involved in the production of many useful products, including protection of scrim glass fabric used for reinforcement of cementitious boards and other products, production of breathable fabrics woven from coated fibers, fiber optics, and production of various articles (e g., fishing lines or tennis racket string) from coated fibers. Some examples are given below. 

The main property of the outer shell is to provide a protection against the outside weather conditions, mainly rain, snow and wind. In order to avoid excessive sweat accumulation, the outer layer should allow moisture transfer from the body to the environment. Such waterproof, windproof and breathable fabrics (WBF—mainly membranes and coatings) have been on the market for more than 30 years. The waterproof properties and, at the same time, the water vapour transfer are either achieved with a micro-porous or a hydrophilic structure, or a combination of both technologies (bi-component WBF). Waterproofness and breathability are contradictory requirements and, therefore, a compromise has to be found between protection and comfort properties. This compromise is usually achieved by adapting the porosity and thickness of such WBF layers. 

Mukhopadhyay, A., Vinay Kumar, M., 2008. A review on designing the waterproof breathable fabrics part I fundamental principles and designing aspects of breathable fabrics. J. Ind. Text. 37, 225-262. 

Ren, Y.J., Ruckman, J.E., 2004. Condensation in three-layer waterproof breathable fabrics for clothing. Int. J. Cloth. Sci. Technol. 16, 335-347. 

Methods of incorporation of membranes and application of coatings in the layered construction of breathable fabrics 39... 

Fig. 2.1 Construction of a typical waterproof breathable fabric (accessed from http //www. evo.com/waterproof-ratings-and-breathability-guide.aspx).

With technological advancements, however, waterproof breathable fabrics can provide the wearer with a greater level of comfort in many adverse situations. 

Waterproof breathable fabrics prevent the penetration of liquid water from the outside to the inside of clothing while permitting water vapour from the inside of clothing to pass to the outside atmosphere (Fig. 2.1). Because waterproofing and moisture permeability are two mutually contradictory functions, producing a material which has both these properties has proved to be a major challenge for manufacturers of so-called waterproof performance fabrics. In this chapter, the fundamental principles of vapour permeability of different kinds of breathable fabrics, along with different techniques for construction, are discussed. 

A few breathable fabrics falling within this category are ... 

One of the important developments in, and applications of, textiles is the manufacture of intelligent waterproof breathable fabrics based on shape memory polymers using shape memory polyurethanes. The fabric restricts the loss of body warmth by stopping... 

Another distinct development of smart breathable fabric is based on biomimetics. Biomimetics is the mimicking of biological mechanisms, with modification, to produce useful artificial items. The water vapour permeability of fabric coatings can be improved by incorporating an analogue of the leaf stomata which open when the plant needs to increase moisture vapour transpiration and close when it needs to reduce it. Currently, there are several developments in the area of waterproof breathable fabrics based on biomimetics, as discussed below. 

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