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Finishing of technical textiles - II

Army clothing

Usual fibre composition: 100 per cent CO, CO/PES 85/15, CO/aramide 65/35

Finishing goals: dimensional stability, water/ oil repellency, waterproof, flexible at low temperatures, fast to washing and dry cleaning, flame retardancy, heat-resistant, IR remission.

The finishing’s can be effected by any of following procedures :

• Padding
• Coating

Besides these two basic procedures there is requirement of either pre- calendaring or post calendaring to enhance the effects.

Finishing product range include:

Repellent/release

Mainly, flurochemicals applied by padding or coating onto the textiles to impart resistance to water pressure, water repellent, oil repellent (stain repellent), stain release properties .Ciba(r) OLEOPHOBOL or Ciba(r) PHOBOTEX range of products provide durable effects .

Flame-retardant

Organic phosphorus compound, applied by padding normally. Ciba(r) PYROVATEX CP New imparts durable effects especially required for work wear. Ciba(r) PYROVATIM PBS gives semi-durable effects required for the upholstery industries of the automotive & aviation industries.

Waterproof

Paraffin wax based products giving excellent water proof properties to a range of textile fibres such as cotton, polyamide, PAN and wool. Ciba(r) HYDROPHOBOL ZAN or APK gives good water repellent effects and high water pressure resistance.

Fast to rotting/mildew resistant

Emulsion free of metal salts consisting of fatty acid esters of dihydroxydichlorodiphenylmethane and a benzimide azoles derivative. Ciba(r) FUNGITEX ROP can be used for fungicidal finish of cotton, linen, polyester/cotton fabrics for tents, tarpaulins and rucksacks.

Antistatic

Modified organic phosphorous compound are extremely effective at preventing static build up. Ciba(r)ZEROSTAT(r) AT new is an extremely effective antistatic agent for treating of synthetic fibres and their blends to overcome electrostatic-related problems in fabric use.

Thermal insulation

Aluminum foil coated under high vacuum conditions: the foil is glued on in high vacuum, so that a bond between the surface of the fabric and the foil are guaranteed at nearly every point; for technical applications (mainly in use with Kevlar or preox/p-aramid) to insulate thermal radiation. Also in use as outside of suits and clothes made from Kevlar (melting ovens and blast-furnace plants)

Weather protection

Membranes coated onto protective clothing (e.g. firemen) assure, that no water can penetrate the clothing from outside to inside; at the same time the membrane has good porosity, i.e. vapor (body perspiration) can penetrate through the membrane to the outside.

Slip resistant

Aqueous based coating using acrylic/ poly urathane compounds are used for adhesion of yarns successfully to prevent slippage under stress. Ciba(r) DICRYLAN AHS gives good adhesion on nearly all substrates, especially on polyester and polyamide.

Handle modification/abrasion resistance

Applied by padding with silicone or polyurethane compounds onto the fabrics to achieve soft, supple and smooth surface. Ciba(r) ULTRATEX(r) and DICRYLAN(r) ranges offer wide variety of handles and abrasion resistance.

Dimensional stability

Treating of cellulosics with resins offer these fabrics good dimensional stability. Good shrinkage control and shape retention of protective clothing are maintained even after several washes by using Ciba(r) KNITTEX resins.

Conclusion

Technical textiles are value added products which are produced out of either high tech non- conventional polymers which enhance specific properties or else special high tech finished conventional fibres or a combination of both.

Technical textiles are likely to play an important role in infrastructure development, agriculture, medical, hygiene and specialised sports and apparel wear as major applications. Alternatively developments in functional finishes could shape the future of the textile industry on to the path of growth in quantum leaps and bounds.

(The author is manager - technical support, Ciba Specialty Chemicals (India), Textile Effects- TC. The previous issue inadvertently mentioned that the author is with Clariant. The error is regretted.)