Stabilization finish, fabric

The knitted fabric is subjected to a finishing operation in which a suitable backing material is appHed to penetrate the yam contact points and stabilize the stmcture. This process is usually accompanied by a heat treatment which stabilizes the fabric and conditions the pile. 

For application of these fluorochemical finishes to textile fabrics, an extremely important factor is their formulation into suitable aqueous emulsions or dispersions. The quality of the formulation has a critical influence on stability during storage and application, as well as the efficacy of treatment and durability [501,502]. In particular, the choice of surfactant(s) for emulsifying or dispersing must ensure good stability with freedom from deposition on rollers, yet must not impair the water and oil repellency of the finished fabric. No individual product fulfils all requirements hence specifically formulated products are available for certain fibre types. 

Table IX summarizes the results of a number of trials in which a durable press, fabric stabilization finish was applied to polyester cotton fabrics of various weights. The major conclusion to be drawn from this work is that while productivity (range speed) was significantly improved by switching to foam finishing, energy savings were less than predicted on the basis of a 54% reduction in amount of water applied to the fabric,...

Low add-on finishes conserve energy and pollution (less chemicals needed for a given level of performance) [71], The method also conserves energy and speeds up production. Because there is less water used, the chemicals (if applied properly) are more evenly distributed throughout the fabric. Thus they more efficiently stabilize the fabric. 

The woven fabric can be supplied either off-loom (greigh goods) or subjected to a finishing process. The two most common to the filtration industry are heat treatment and calendering. Heat treatment is applied to synthetic cloth in order to stabilize the fabrics and make them more suitable at elevated temperatures. Calendering uses high-pressure, hot rollers whereby... 

FWWMR Finish. The abbreviation for fire, water, weather, and mildew resistance, FWWMR, has been used to describe treatment with a chlorinated organic metal oxide. Plasticizers, coloring pigments, fiUers, stabilizers, or fungicides usuaUy are added. However, hand, drape, flexibUity, and color of the fabric are more affected by this type of finish than by other flame retardants. Add-ons of up to 60% are required in many cases to obtain... 

Copper-based thermal stabilizers are also effective photostabilizers for nylon. They can be added before polymerization, or the soluble salts (eg, CuSO can be appHed to fibers as part of the finish or to fabrics as post-treatments. The effectiveness of the copper salt—alkah haUde system added to prepolymer in retarding phototendering and photoyeUowing of the resulting spun yam is illustrated in Figure 5. 

In addition to conferring transparency on these polymers, the amorphous noncrystallizable nature of polysulfones assures minimal shrinkage during fabrication of the resins into finished parts. The absence of crystallinity also assures dimensional stability during the service life of the parts where high use temperatures are encountered. Good dimensional stability is important to many structural and engineering applications. 

The foamable compositions are designed so that the foam can be easily collapsed after being applied to the fabric. The degree of stability and ease of collapse of the foam are dictated by function and application mode of the finish (Table III). 

Foam stability Is less critical for resin finishing or hand modification. However, It must not collapse prior to application on the fabric otherwise the composition will act like a conventional finish and result In high wet pick-ups. 

In the foam process, a concentrated solution of the finishing chemicals compounded with suitable foaming agents and, If necessary, foam stabilizers Is mechanically foamed so as to Incorporate by volume 50 to 95% air, This foam, having an appearance quite similar to shaving cream, Is applied to the fabric. The foam-coated fabric Is then subjected to a mechanical pressure which collapses the foam. The fabric Is then dried and cured In the conventional manner. 

For the plant trials which will be subsequently discussed, a 7% solids durable press, fabric stabilization conventional finish and a 14% solids foamable counterpart were applied to polyester/cotton fabrics of various weights. 

A defect of regular rayon fabric in the absence of a cross-linking finish is its solubility in alkali with consequent loss of strength and dimensional stability. These defects have been largely overcome in the high performance rayons. Mitchell and Daul (43) reported that regular textile grade rayon staple fiber accounts for 70-80% of the output of the rayon industry. 

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