| 摘要 |
1,144,376. Spinnerets. SOC. RHODIACETA. 7 Nov., 1966 [8 Nov., 1965], No. 49804/66. Heading B5B. Yarns in which most of the elementary filaments have an X cross-section, are made by dry spinning a solution of a filament-forming material in a volatile solvent through a spinneret perforated with square holes in which the drying conditions are substantially identical on two adjacent sides of each square hole. Preferably a spinneret is used in which the said square holes are so arranged that each of them has one diagonal making an angle of less than 10 degrees with the radius of the spinneret face which passes through the centre of the hole. Thus in Fig. 1 one diagonal of each hole lies on a radius of the spinneret face passing through the centre of the hole, while in Fig. 3, the holes 2 are arranged in three rings each having four holes, so that one of the diagonals of each hole coincides with a radius of the spinneret. In Fig. 4, the holes 2 and 2<SP>1</SP> are arranged along sides of a polygon concentric with the spinneret face and the holes 2 are so oriented that one of their diagonals coincides exactly with a radius of the spinneret, and the holes 2<SP>1</SP> in such a way that one of their diagonals makes an angle of 7 degrees with a radius of the spinneret. Cellulose acetate filaments may be dry spun from a solution of a secondary cellulose acetate in acetone, and cellulose tri-acetate filaments may be dry spun from a spinning solution comprising a mixture of methylene chloride and a lower aliphatic alcohol, especially methanol or ethanol. A mixture of carbon disulphide and acetone may be used as spinning solvent for polymers based on vinyl chloride. Yarns may be obtained in which at least 90% of the constituent filaments have a cross-section in the shape of an X. Examples given relate to the spinning of cellulose diacetate and triacetate. |
