| 摘要 |
<p>1439883 Repaceable filter and die unit CF SCHEER & CIE 31 July 1974 [2 Aug 1973] 33814/74 Headings B5A and B5B [Also in Division B1] A die head, for the extrusion of a plurality of molten plastics strands is provided with a combined filter and multiple orifice die unit 50, which is slidably displaceable from the remainder of the die head, transversely of the direction of flow of the plastics material, for cleaning and replacement by a similarly displaceable unit, the displacement being effected on a pair of guide rails 38 which are resiliently loaded, by diaphragm springs 49, to urge the unit into sealing contact with the remainder of the die head at their surfaces at which the sliding is effected. The unit 50, Fig. 2, comprises a filter layer 104 upon a support member 102 having ducts 100, clamped by bolts 52 between shoulders 68, 70, of a die unit part 50a and the die 50b. The unit is slidable against upper and lateral die head parts 26c, 74, Fig. 1, upon the pair of guide rails 38 which are each pivotably located, about rods 36, for the resilient loading against the die head by the diaphragm springs 49 which are urged against the rails 38 by nuts 46 on threaded spindles 42. The die head upper part 26c and the unit part 50a are of hardened steel, and an aluminium bronze part 58 is screwed to the part 50a for the sliding engagement with the part 26c. The lateral die head parts 74, against which the part 50a slides, are also of soft material and are bolted to the die head, with one thereof being adjustable by a screw 78. For changing of the unit, further guide rails 106, 108 are provided on either side of the head so that a cleaned unit 50 can be displaced by a pneumatic cylinder from the rails 108 on to a chamfered entry to the rails 38, and into the head to displace a unit 50 from the head on to the rails 106 for cleaning. Each unit is provided with electric or liquid heating units 80, 110, and the unit 50 to be displaced into the head is heated on the rails 108 by a heater 112. The extruder 10 and die head are also provided with electric or liquid heating jackets 12, 20, 22, and the head is provided with an insulating jacket 24. The plastics strands extruded from the die 50 are drawn through a cooling device 82 from which, during changing of a unit, the strands are diverted to waste by a shoot 96, which is displaceable by a pneumatic cylinder into position beneath the die 50, along slots 94 of a rail 88. Adhesion of the strands to the shoot 96 is prevented by a film of water discharged from a chamber 95.</p> |
