| 摘要 |
1,103,728. Synthetic filaments having crimp potential. SNIA VISCOSA SOCIETA' NAZIONALE INDUSTRIA APPLICAZIONI VISCOSA S.p.A. 10 June, 1965 [19 June, 1964], No. 24583/65. Heading B5B. A composite filament having a potential crimp is produced by bonding together in sideby-side relationship at least two mono-filaments at least partially formed by two synthetic polymer components differing from one another in their shrinkage characteristics when heated or in the extent to which they swell when contacted with a swelling agent, at least one of the monofilaments being itself a composite filament having a sheath-core structure, the core component of said composite filament differing in its shrinkable or swellable characteristic from the single polymeric material of the other monofilament, if the latter is a homofilament, or from the core component thereof if said other monofilament is also a composite filament of sheathcore structure, the sheath component of the first composite monofilament being the same as or similar to the single polymeric material or to the sheath component of the said other homofilament or respectively composite filament, so that the two monofilaments will be firmly and permanently bonded together at their interfaces when they are contacted to form the final composite filament owing to the compatibility of the polymers constituting the contacting portions of the individual monofilaments. The components of the final composite filaments may be bonded together by melt-spinning through at least two adjacent orifices of a spinneret two monofilaments and causing these monofilaments to contact one another along their length immediately after they leave the spinneret and while they are still molten so that they become bonded together along their length. Alternatively the components of the final composite filaments may be contacted while they are in the form of melts in a duct of a spinneret prior to extrusion simultaneously through the same spinneret orifice under non-mixing conditions. As shown in Figs. 5 and 7, a spinneret suitable for the process of the invention comprises a spinneret plate 10 provided with pairs of adjacent orifices 18, 19, which are supplied from the central chamber 13, duct 15 and annular chamber 16 with a polymer B. In addition the orifices 18 are supplied with a different polymer A from an annular chamber 14 through the nozzles 17 to form the core component of the composite sheath-core monofilament extruded through the orifices 18. In the spinneret shown in Fig. 9, the polymer B is fed through the separate passageways 21 and 22 which converge to the spinneret orifice 20. The polymer A is injected into the stream of polymer B flowing through the passageway 21 by means of the nozzle 23. The cores of the monofilaments may consist of the same or different polyesters and their sheaths of the same or different polyamides.
|
