GB982714A - Improvements in or relating to melt-spinning synthetic polymer filaments - Google Patents

Abstract

982,714. Melt spinning synthetic filaments. BRITISH NYLON SPINNERS Ltd. Sept. 19, 1963 [Oct. 12, 1962], No. 38709/62. Addition to 901,398. Heading B5B. The apparatus of the parent Specification (wherein an apparatus for melt-spinning a synthetic linear polymer comprising a metering pump for forwarding molten polymer to and through a filter and thence through an orifice or orifices in a spinneret plate, a filter and a spinneret plate is provided with means for continuously supplying an inert gas to the vicinity of the face of the spinneret plate) is modified in that the means comprise a number of holes equispaced around the outside of a pack containing the filter and spinneret assembly, said holes leading from the upper part of a recess in a metal block forming part of the spinning head or unit, into which recess said pack is fitted and leading into a space of annular cross-section which surrounds both the lower part of the pack and the spinneret and terminates at its lower end in an annular slot or mouth leading into a shallow zone adjacent to the face of the spinneret plate. As shown in Figs. 1 and 2, a steam supply pipe 1 is drilled through the metal-block 3 of a melt spinning unit and discharges into a recess 5 in which is fitted a pack 7 containing a filter and spinneret assembly. At the discharge end of pipe 1 is fitted a plug 11 having passing through it a metering orifice 13. The pack 7 is forced into operating position within the port 5 by screwing pack nut 15 into the metal block 3. The shoulder of the pack nut 15 bears against a complementarily shaped flange 17 of the pack easing. Just above the area of contact, a number of equi-spaced holes 19 are drilled through flange 17, through which holes the steam passes uniformly from the upper part of the recess 5 into the space 21 of annular cross-section surrounding the lower part of the pack 7. This annular space broadens out at its mouth, opening into the shallow zone adjacent the face of the spinneret plate 9, and its walls are directed inwardly near the mouth towards the centre of the spinneret plate. The shoulder of pack 7 is chamfered to allow for easy passage of steam around the upper portion of the pack. The modification of the parent Specification enables a uniform supply of steam to be obtained even if a diffusor ring is omitted and whether the steam is at atmospheric pressure or at a higher pressure when approaching the vicinity of the face of the spinneret plate. Specification 942,975 also is referred to.