A process for making synthetic polymer monofilaments of improved transverse properties and monofilaments provided thereby

摘要

1,037,935. Treating monofilaments with steam. BRITISH NYLON SPINNERS Ltd. April 13, 1965 [April 21, 1964], No. 16426/64. Heading B5B. An oriented monofilament of a synthetic polymer, particularly a polyamide such as polyhexamethylone adipamide is exposed to an atmosphere of saturated steam for a period of time which permits diffusion of water vapour into the monofilament to the extent that, only in the region of the monofilament adjacent the peripheral surface thereof, are the polymer crystals disoriented. The process is continuous and improves the transverse properties of the monofilament, as evidenced by resistance to abrasion and flexing. The atmosphere of saturated steam may be maintained at a pressure at which its temperature is at least as high as the melting point of the synthetic polymer in such an atmosphere. The monofilament may consist of polyhexamethylene adipamide and the atmosphere of saturated steam may be maintained at a pressure of at least 105 p.s.i. (gauge) corresponding to a temperature of at least 172‹ C. and the period of time during which the monofilaments are in contact with the atmosphere is 15 to 100 milliseconds. The monofilament may have a denier less than 83 and comprise an oriented core portion and a disoriented sheath portion, the latter, for example extending inwardly from the surface of the monofilament to a depth which is 5 to 30% of the radius of the monofilament.