| 摘要 |
1,087,939. Artificial filaments having crimp potential. FARBWERKE HOECHST A.G. Feb. 22, 1965 [Feb. 21, 1964], No. 7628/65. Heading B5B. Three-dimensionally crimpable filaments are made by melt spinning a homogeneous melt of linear polymers, the process comprising producing two separate streams of the homogeneous melt, the ratio of the gravimetric rate of flow of the streams being within the range of 1: 1À5 to 1: 4, extruding them together without mixing them through the or each extrusion orifice of a spinneret, withdrawing the thus formed filament from the spinneret, cooling and thereby solidifying the filament and cold drawing the solidified filament at a draw ratio of 3 to 4. The linear polymer may be a polyester, a polyamide or a polyalkylene. The two separate streams of melt having different gravimetric rates of flow may be produced and supplied to the spinning head by means of two separate extruders each communicating with the spinning head through its own separate duct and supplying the spinning head at a gravimetric rate of flow differing from that supplied by the other extruder. The separate streams of melt may be joined in the spinneret immediately before leaving the spinneret extrusion orifice or in the inlet to the extrusion orifice. The two separate streams of melt may be fed to a spinneret having several extrusion orifices in such a manner that each stream is uniformly distributed over all the orifices and the subdivided separate streams are united again in each orifice just before the united streams leave the orifices in the form of filaments. The solidified drawn filaments may be maintained for 1 to 5 minutes at a temperature within the range of 120‹ to 180‹ C. or treated for this period with boiling water or saturated steam at atmospheric pressure whereby the filaments acquire a three-dimensional crimp of very high retentivity. Staple fibres obtained from the filaments may be crimped in the same manner.
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