Patent GB-1350496-A (GB)
Title: Melt spinning apparatus
IPC: D01D1/04
Filed: 1971-09-14
Abstract: 1350496 Melt spinning assembly IMPERIAL CHEMICAL INDUSTRIES Ltd 10 Aug 1972 [14 Sept 1971] 42772/71 Heading B5B A melt spinning assembly comprises a pack 3 with two opposed heat transfer surfaces 4, 5 and a pack setting 1 adapted for heating to a controllable temperature and containing a socket 2 adapted for receiving the pack, the socket having two opposed heat transfer surfaces 6 and 7 adapted for relative displacement whereby area contact is effected with the heat transfer surfaces of the pack and the pack is gripped.  In operation, pack 3 is inserted in socket 2 and screw 73 is rotated, urging platen 8 leftwards. The application of pressure by the screw at a single location allows angular displacement of the platen permitting parallelization of surfaces 5 and 7. The feed of fibre-forming synthetic polymer melt is through aperture 14 in the first heat transfer surface 6 which, with pack 3 in position, communicates with an aperture 15 in pack 3, leading via feed pipe 16 to spinneret 17. Hence tightening the screw facilitates the formation of a liquid tight joint, ensured by the provision of a polytetrafluoroethylene gasket fitted in recesses cut in the pack and setting. In Fig. 2, the hollow platen of Fig. 1 is replaced by a wedge 20 and conducting member 23. In operation jacking screw 26 is used to exert pressure downwardly on the wedge 20, thus effecting the relative displacement of heat transfer surfaces 6 and 7 and contact with the heat transfer surfaces of the pack. The curvature of surfaces 24 and 25 also allows angular displacement of surface 21, facilitating parallelization. In Fig. 3, the wedge is in two parts 30, 31 each bearing one of the wedging surfaces, and having a common cylindrical surface 32. Parts 30, 31 are slidably coupled by bolt 33 which is screwed into part 31 after passing through a hole 34 in part 30. Hole 34 is vertically elongated to allow relative vertical movement of parts 30 and 31. Jacking screw 35 exerts downward pressure on part 31, which pressure is transmitted to part 30 through extension 36 bolted to part 31 and compression spring 37. When not in operation, spring 37 urges parts 30 and 31 slidably with relation to each other so as to result in a minimum wedging angle. In operation, downward pressure on 31 causes relative displacement of heat transfer surfaces 6 and 7 and the wedging angle progressively increases until it conforms to the angle between faces 5 and 7, giving good heat transfer between wedge 30, 31 and pack 3 and between wedge 30, 31 and the setting. At the same time the lateral pressure exerted by the wedge on pack 3 results in the first heat transfer surface 4 of pack 3 being forced into close contact with the first heat transfer surface 6 of setting 1, thus ensuring good heat transfer. In Fig. 4, the change in wedge angle is achieved by making the wedge from a number of members each comprising a proportion of each of the wedging faces of the wedge. Wedge 40 is composed of members 40a ... 40o each separated from its neighbour by a Belville washer 41 and each bearing heat transfer surfaces 7 and 42. Pressure transmitted to the members by jacking screw 43 causes bending of each with consequent reduction in the angle between the surfaces 7 and 42 producing an overall reduction in the effective wedging angle (angular displacement). At the same time relative linear displacement between surfaces 6 and 7 occurs and the lateral pressure exerted by the wedge on the pack 3 results in heat transfer surface 4 of pack 3 being forced into close contact with heat transfer surface 6 of setting 1, thus improving heat transfer.