| 摘要 |
<p>Acetone-soluble copolymers of acrylonitrile and vinylidene chloride are dry-spun into an evaporative atmosphere and the freshly extruded fibres are stretched from 75 to 300% at from 15 DEG -40 DEG C. Preferably, the fibres are stretched 100-300% at ordinary room temperature. Stretching may be effected in air or in water or other non-solvent for the fibres, which may contain a textile lubricant. The fibres may subsequently be stretched a second time from 500-2,000% of the length immediately before this second stretching, especially from 700-1,500%, at not less than 95 DEG C., e.g. in hot air, steam or hot water, preferably in saturated steam at superatmospheric pressure. Between the two stretching operations the fibres may be collected and stored on bobbins. After the hot-stretching, the fibres may be annealed by heating while they are free to contract, e.g. in water at 90 DEG -100 DEG C., or in saturated steam at atmospheric pressure. Fibres so treated have high dimensional stabilities to wet and dry heat. Specifications 643,198, 674,323, 709,995, 849,029 and 897,697 are referred to.</p> |
