| 摘要 |
533,304. Artificial filaments &c. DU PONT DE NEMOURS & CO., E. 1. Aug. 9, 1939, No. 23028. Convention date, Aug. 9, 1938. [Class 2 (ii)] Artificial filaments, ribbons, and the like, are obtained by extruding a molten filamentforming composition and passing a cooling medium with a substantially straight-line flow across the filaments while they are being transformed from the molten to the solid state. As shown in Fig. 1, molten material is extruded through a spinneret 11 to form a bundle of filaments 12. The filaments pass a short distance through the atmosphere and then pass through chamber 13 which is provided with cooling-air inlets 15, 17. A screen 19 is provided so that the air has a straight-line flow as it passes across the path of the filaments. If desired several parallel screens may be provided in front of screen 19 and the streams of air entering at 15 and 17 may be kept separate by the provision of a horizontal partition. Another screen may be provided on the opposite side of the chamber 13. As shown in Fig. 3, the chamber 55 is divided into sections by the partitions 57, 59. Cooling-air is directed in straight-line flow on to the filaments by means of the inlets 65, 66, 71, and screens 67, 69, 75. The orifices of the spinneret may be arranged so that each filament is exposed to the direct flow of cooling air. In an example, polyhexamethylene adipamide is melted in a chamber provided with a melting grid. The molten mass is passed through a filter screen and then extruded in apparatus as shown. A magnesium carbonate insulating ring is fastened between the spinneret and the cooling chamber in order to insulate these parts from each other. The spinning speed may be 3,000 feet per minute. Synthetic linear polyamides, polyesters, polyethers, polyacetals, or mixed polyamide-polyesters, or ethylene polymers, vinyl polymers, polystyrene, polyacrylic acid derivatives, or cellulose derivatives, may be used as filament-forming substances. The compositions may contain dyes, pigments, delustrants, resins, or plasticizers. Instead of using screens of fine mesh for securing straight-line flow, fabrics, glass-wool screens, or other devices may be used. Specification 471,590 is referred to. |
