Patent GB-760329-A (GB)
Title: Improvements in and relating to melt spinning apparatus
IPC: B29C48/05
Filed: 1953-06-10
Abstract: <PICT:0760329/IV(a)/1> A multiple apparatus for melt-spinning synthetic linear polymers comprises a <PICT:0760329/IV(a)/2> number of spinning heads, pipe - line connections for feeding the spinning heads from a single source of molten polymers, a single jacketed chamber enclosing all the spinning heads and having means for circulating a heating fluid through the jacket, and thermal insulation for the chamber, which is provided with openings for the pipe-line connections, for the drive shafts of the spinning pumps of the spinning heads, and for the free outlet of the filaments downwardly extruded from the spinning heads.  As shown in Fig. 1 (partly a plan view and partly a horizontal section), a molten filament-forming material is supplied to four spinning heads from a common source (not shown) through the single feed pipe 10 and branch feed pipes 14.  Each spinning head comprises (as shown in vertical section in Fig. 2) a spinneret plate 11 housed in a block 12 containing a filter and a metering pump 13 supplied by the branch feed-pipe 14.  These pipes are preferably provided, in the vicinity of the pump, with devices 15 for isolating each pump from its feed pipe when the pump is to be disconnected.  The devices are preferably of the type described in Specification 760,316 and comprise a constriction in the pipe, surrounded with a small jacket through which a cold fluid flowing in from a pipe 16 and out through a pipe 161 may be circulated, causing the spinning material to solidify within the constriction and thus form a plug stopping the supply of molten material to the pump.  The feed manifold 10 and feed pipes 14, the pumps 13 and the spinneret housings 12, together with the pipes 17 leading from the pumps to the spinneret filters, constitute, when connected, a relatively rigid assembly housed in a single open-top jacketed chamber 18.  A heating fluid, which may be a condensing vapour or a liquid, e.g. a mixture of diphenyl oxide and diphenyl, is circulated through the jacket of the chamber 18, being supplied to the bottom of the jacket from a central boiler or heater through the inlet pipe 29 and being discharged from the top of the jacket through outlet pipe 19 into the manifold 32 from which it returns through pipe 33 to the boiler or heater.  A number of jacketed chambers 18 may be arranged end-to-end to form a battery of units, each unit containing a group of spinning heads. Thermal insulation panels 20, 21, 22 are arranged at the front, rear and top of the chamber 18, the panel 22 being removable.  The bottom of the chamber is provided with a fourth insulation panel having openings 28 which allow passage of the extruded filaments and are large enough to permit removal and replacement of the spinnerets.  The spinneret housing 12 is supported by a sleeve 30 attached to the jacketed chamber 18 by bolts 31.  As the top of the chamber 18 is open and the insulating panel is removable, the chamber 18 may be removed from the spinning head assembly by lowering it, after removing the panel, leaving the assembly in position.  By reversing this operation, the chamber may be replaced.  The front of the chamber 18 and the panel 20 covering it are provided with openings which register with the pumps 13 and are wide enough to permit the individual pumps to be withdrawn and changed, and are normally closed by removable insulating discs 23 through which pass the shafts 24 of the pumps.  Rods 25 (Fig. 1) connect the vertical plate members 26 which in turn are attached to the pump supports 27, the purpose of all these members being to render the pump group assembly as rigid as possible.