Repellent finishes textiles treated

The oldest repellent finish is to repel water. The purpose of this finish is self evident. Drops of water should not spread on the surface of the textile and should not wet the fabric. The drops should stay on the surface and easily drip off. Similarly, oil repellent finishes should prevent oily fluids from wetting treated textiles. In a similar manner, soil-repellent finishes should protect textiles from both dry and wet soils. In all cases, the air permeability of the finished fabric should not be significantly reduced. Waterproofing treatments will not be covered in depth. A waterproof textile should withstand the hydrostatic pressure exerted by a column of water from at least aim height before the first drops of water penetrate through the fabric. In practice this is mostly achieved with coatings which have the disadvantages of stiff handle, lack of air and vapour permeability and consequently poor wear comfort. 

Evaluation of textiles treated with repellent finishes... 

Fluorochemicals. Fluorochemicals are the most important class of repellents for textiles. They are the only repellents that provide repellency to water, waterborne stains, oil, oilbome stains, and oily particulates. The various products have a variety of repellency and durabiHty properties for certain fabrics, and the specific compositions ate proprietary. The first company to market fluorochemical repellents was 3M iu the 1950s (Scotchgard Fabric Protector), followed by DuPont (Zepel and Teflon Fabric Protectors). Several other companies such as Autalux Corporation, Ciba Specialties, Eastern Color Chemical, Glo-Tex Chemicals, IVAX Industries, Liadley Laboratories, NICCA U.S.A, Piedmont Chemical, Sedgefield Specialties, Sequa Chemicals, and Yorkshire Pat-Chem also market such finishes (17). Fluorochemical finish appHcation areas include rainwear, upholstery, drapery, and automotive fabrics, roofing materials, and carpeting. Both natural and synthetic textile fibers can be treated. 

Repellent finishes are important components of many protective textiles. Apphca-tions for repellent textiles range from medical textiles to raincoats. The low surface energies provided by repellent finishes can keep solid and liquid soils from adhering to treated fiber surfaces. Finishes based on hydrocarbon and silicone chemistries can yield water repellent textiles, while fluorochemicals are necessary to achieve the low surface energies needed for dry soil and oil repellency. "... 

A fibre containing a repellent for dust mites (one of the leading sources of human allergies) has been introduced by the French specialist Rhovyl. Where previously the method was to treat finished textile products with massive amounts of acaricide sprays or moist powders, the French company has approached the problem by introducing a mite repellent in the fibre itself, using some unique technology. 

In order to obtain functional fibres and textiles to meet the special requirements for buUdtech applications, a large variety of properties can be engineered by finishing and post-treating fibres, e.g. for dirt or oil repellence, UV-protection, flame retardance, higher tensile strength or abrasion resistance. 

In general, the skin sensorial comfort is negatively affected by hydrophobic and smooth surfaces that easily cling to sweaty skin, or which tend to make textiles stiller. The use of spun yams and hydrophihc treatments improves the skin sensorial wear comfort. These tests are especially important for military clothing treated with insect repellent or flame retardant finishes, as these finishes, while providing functional properties to textiles, may negatively affect their feel and handle. 

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