GB942512A - The production of yarns - Google Patents

Abstract

Yarn is formed by stretching regenerated protein e.g. freshly spun casein, continuous filaments by 20-60% while wet, drying while still stretched and combining e.g. uniformly or randomly mixing, the dried filaments or staple thereof with less shrinkable continuous filaments or staple fibres, spinning and, optionally, doubling. The less shrinkable fibres may be of regenerated cellulose, cellulose acetate, polyethylene terephthalate, polyamide, polyacrylonitrile, cotton, flax or wool or another regenerated protein. The potential shrinkages of the constituent fibres differ by at least 5% and the proportion of more shrinkable fibre is 20-50%. The yarn or fabric made therefrom is bulked by immersion in an aqueous fluid e.g. hot or boiling water or steam, which may occur in a normal e.g. dyeing or finishing, treatment, to cause differential shrinkage of the fibres, followed by drying under minimum tension. The stretched fibre may be only partially dried or temporarily set e.g. by a cross-linking operation the effect of which is removed by aqueous treatment, to retain its full shrinkage potential pending a delayed bulking treatment.