| 摘要 |
1,141,394. Melt spinning slubbed filaments. TOYO RAYON K.K. 9 Aug., 1966 [9 Aug., 1965; 15 Nov., 1965; 22 July, 1966], No. 35661/66. Heading B5B. Slubbed drawn filaments of a melt-spinnable organic synthetic polymer are characterized in that the ratio of the cross-sectional area of the parts (P) of the filaments between the slubs to that of the slubs (Q) is within the range 1: 2 to 1: 15, preferably within the range 1 :4 to 1:10, and the frequency of the slubs is at least one and preferably 2 per 30 mm. length of the filament, said cross-sectional configuration occurring continuously along the length of the filament. The polymer may be a synthetic homopolyamide, a copolyamide, consisting chiefly of polyamide units or a blend of a polyamide with another polymer, the polyamide component predominating. The polymer may be a polyhexamethylene adipamide or a polycaprolactam, the relative viscosities of the polymers at 25‹ C., measured in 98% by weight sulphuric acid being 2À2 to 6À0 and 2 to 9 respectively. The slubbed filaments may be made by meltspinning the polymer under such conditions that the shear stress to which the melt is subjected during its passage through the or each spinneret orifice is such as to cause the formation of melt fracture, the cooling and solidification of the molten extruded filaments being effected by means of a gaseous cooling medium under non-quenching conditions, and subsequently drawing the filaments. The polymer used may be polyhexamethylene adipamide (nylon-6, 6) having a relative viscosity, # r (measured at 25‹ C. in sulphuric acid of 98% by weight concentration) of from 2À2 to 6À0 and the melt spinning conditions may be such as to exert a shear stress within the range defined by the formula 10<SP>7.5</SP>/#r<SP>1.8</SP>##w#10<SP>6.7</SP>#r<SP>0.87</SP> in which # w ) represents the shear stress (dynes/cm.<SP>2</SP>). Alternatively the polymer used may be polycaprolactam having a relative viscosity of 2-9, and the melt spinning conditions may be such as to exert a shear stress within the range defined by the formula 10<SP>7.7</SP>/#r<SP>1.8</SP>## w #2 x 10<SP>7</SP>.
|
