Patent GB-1135376-A (GB)
Title: A melt spinning device
IPC: B29C48/691
Filed: 1966-05-03
Abstract: 1,135,376. Melt spinning filter device. BARMAG BARMER MASCHINENFABRIK A.G. 3 May, 1966 [5 May, 1965], No. 19558/66. Heading B5B. A filtration device for use in melt spinning comprises a main passageway 1 of square or rectangular cross-section (Fig. 1), provided in a filter block 14 and leading from a source of melt and divided at 2 into two branch passageways also of square or rectangular cross-section, of which one 3, 4 is open and the other 3<SP>1</SP>, 4<SP>1</SP> is closed by shut-off slides 5 and 6. The slides 5 and 6 contain cavities 7 and 8 which are filled with a liquid or a plastic substance through threaded bores (not shown) and which can each be closed by a screw (not shown) which exerts such a high pressure on the medium inside the corresponding cavity 7 or 8 that the associated slide is forced on all sides against the inner walls of the passageway 3<SP>1</SP>, 4<SP>1</SP> by virtue of the elasticity of the slide material. The slide is thereby rendered a liquid tight fit in the passageway, whereby melt is entirely prevented from entering the branch passageway 3<SP>1</SP>, 4<SP>1</SP>. Filter inserts 9 and 10 with perforations 11 are provided in the branch passageways 3, 4 and 31 41 respectively. The filter insert 10 is located between the shutoff slides or slide valves 5, 6 in the passageway 3<SP>1</SP>, 4<SP>1</SP>. The passageways 3, 4 and 3<SP>1</SP>, 41 have at the outlet side of their filter inserts outlet ports 12 and 12<SP>1</SP> respectively which, as depicted in Fig. 2 can be closed by the tip 13 of a bolt 15. Port 12<SP>1</SP>, for example, communicates with pipe 16 which in turn communicates with the atmosphere. As depicted in Fig. 2, the partly withdrawn shut-off slide 5<SP>1</SP> of the branch passageway 3 projects from the block 14 to such an extent that its. box constitutes the upper wall of the passageway and the melt can flow freely through the passageways 3 the filter insert 9 and the passageway 4 into the main passageway which leads directly to the spinneret. When the filter 9 is so clogged with impurities as to require replacement by a clean filter, the pressure prevailing in the cavity 7 is first of all released by undoing the pressure applying screw (not shown), the shut-off slide 5 is withdrawn from the filter block 14 to such an extent that its lower edge is flush with the upper wall and is locked in position by a device (not shown), whereby the melt flows through the port 12<SP>1</SP>, passageway 3<SP>1</SP>, the filter insert 10, the discharge passageway 13 and the discharge pipe 16 into the atmosphere. Air present in the filter insert 10 is thereby discharged into the atmosphere. When the melt discharged from the pipe 16 is seen to be free from entrained air and any visible particles of insoluble impurities, the outlet port 12<SP>1</SP> in the filter insert 10 is closed, the pressure in the cavity 8 of the shut-off slide 6 released and the slide 6 withdrawn and locked in position as in the case of slide 5. The passageway 3, 4 is closed by shut-off slides corresponding to the slides 5 and 6 of the passageway 3<SP>1</SP>, 4<SP>1</SP> and the clogged filter insert 9 replaced by a clean insert.