| 摘要 |
<p>1,176,719. Extrusion dies. BARMAG BARMER MASCHINENFABRIK A.G. 29 Nov., 1967 [14 Dec., 1966; 2 May, 1967], No. 54280/67. Heading B5A. An extrusion die plate 3, Fig. 2, intended for use in extrusion granulators which comprise knives that sweep over the downstream surface of the plate and have means for washing or spraying this face with a coolant, has a plurality of extrusion orifices 4 each lined with heat insulating material, e.g. quartz, glass, ceramics or highalloy refined steels. The linings may be formed by spraying, but are preferably provided by tubes 5 which may be push-fitted, adhesively secured or cast within orifices 4. Numerous embodiments are described, that of Fig. 2 having separate upstream portions 6 of easily machined material situated within conduits 2 of die body 1, the latter being separated from die plate 3 by an insulating layer 8. Modifications of this embodiment are shown in Figs. 3 and 4 (not reproduced). Tubes 5 may not extend to the downstream surface of plate 3, the unlined bores being of larger diameter than the bores of tubes 5, Fig. 5 (not shown). In a modification, Fig. 6, tube 5 is supported within orifice 4 by a number of projections 11, a solidified sheath of the extruding material forming between the tube and the orifice during operation. The downstream surface of die plate 3 may have a wear-resistant surface layer which is either made of heat insulating material or separated from the plate by such material, tubes 5 extending to or through the layer, Figs. 7 and 8 (not shown). Each tube 5 may be composed of several sections, e.g. (26, 27, 28), Fig. 9 (not shown), and have a converging bore, Figs. 9- 14 (not shown). An enlarged tube may feed more than one orifice, Fig. 13 (not shown). Air insulation may be utilized by having a small diameter tube 40, Fig. 15, supported by an insert 41. Fig. 16 (not reproduced), shows a short replaceable narrow bored tube (44) within a relatively massive tube (43).</p> |
