| 摘要 |
Bulk/stretch yarn is produced by heating a yarn containing a blend of 5-75% thermoplastic fibres and 95-25% cellulose (preferably staple) fibres to shrink the former and cross-linking some or all of the latter whereby they retain a "memory" for the physical position in which they were buckled or folded upon themselves as a result of the shrinkage. Thermoplastic fibres may be of polyamides, polyethylene, polypropylene, polyethylene terephthalate, vinyl chloride, vinyl acetate, acrylonitrile, or acrylic or cellulose esters. Cellulose fibres may be cotton, linen, jute, sisal or hemp or of regenerated cellulose. Blending may occur at any stage of yarn production prior to spinning e.g. by the cotton system. Cross-linking agents, with which the yarn may be impregnated e.g. by passage of a yarn or bundle of yarns laid in a plaited pattern on a moving belt through a bath or by spraying thereof, to deposit 0.1-15% of agent (based on the dry weight of cellulose in the yarn) and which may be present at the time of blending include formaldehyde, dialdehydes such as glutaraldehyde and adipaldehyde, hydroxyaldehydes such as hydroxyadipaldehyde, mixed aldehydes such as acrolein, glycidyl aldehydes; reactant type resins e.g. methylol compounds such as methylated methylol urea, dimethylol ethylene urea, dimethylol triazines, trizones; polyacetals of polyhydroxy compounds e.g. as described in U.S.A. Specification 2,786,081; divinyl sulphone; dihalohydrines e.g. dichlorohydrin; di- and tri-aziridinyl phosphine oxides and sulphides as described in U.S.A. Specification 2,859,134; heat-hardenable resins e.g. urea formaldehyde, and including the methylol-amino-epihalohydrin compounds described in Specification 796,815; and compounds or resins described in U.S.A. Specifications 2,504,835, 2,696,477 and 2,711,971 and in Specification 732,573 (including condensation products of epichlorohydrin with ethylene glycols). The blended yarn may be impregnated with a catalyst, preferably before shrinking to avoid premature curing. Curing may be effected simultaneously with drying or shrinking the yarn.
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