| 摘要 |
1324029 Extruding electrodes GREAT LAKES CARBON CORP 23 Oct 1970 [7 Nov 1969] 50549/70 Heading B5A [Also in Division C1] Green carbon electrodes, comprising mixtures of carbon and/or graphite particles with a resin, tar, or pitch binder and for subsequent baking to 2,600‹ C. for use as electrodes for steel furnaces, anodes for brine electrolysis, and graphite for nuclear reactors, are extruded through a die outlet 7c to which the mixture is impelled by a mechanically or hydraulically actuated ram 2, through successive die sections A, B, C of respectively decreasing, increasing, and decreasing cross-sectional area. The particles are preferably acicular and their passage through the increasing area section B, intermediate the sections A, and C, produces an orientation intermediate the axial and transverse electrode directions to produce a reduced ratio of the transverse to the axial coefficient of thermal expansion as compared with particles extruded under purely axially aligning conditions. The reduction or increase of cross-sectional areas in the sections A, B and C is in a ratio of inverse ratio of from 1À25 to 15 to 1, the reduction ratio in section A is preferably 1À25 to 12 times as great as that in section C, and the final crosssection in section A, is preferably equal to or less than the final cross-section in section C. A section of constant cross-section may as shown be provided intermediate the sections B and C, and the section C may be followed by a section of constant, and then by sections of respectively increasing, constant, decreasing and then constant area. The cross-sections throughout the die may be circular, rectangular, or hexagonal. Various die dimensions, and angles for the sections B and C are specified, and various extrusion examples are given. The die may be heated by separately controlled surrounding heating coils. |
