GB742662A - Extrusion apparatus - Google Patents

Abstract

742,662. Mixing appliances. NATIONAL RUBBER MACHINERY CO. Feb. 24, 1953, No. 5195/53. Class 86. [Also in Group V] Within a stationary extrusion cylinder 3, Fig. 1, which is internally helically ribbed, rotates an externally continuously ribbed feed screw 2. The ribs on the cylinder are, over at least a major portion of the total ribbing of the cylinder, of the same hand as the ribs on the screw : as shown the whole of both sets of ribs is right-hand. The cylinder is formed, for a minor portion of its length, with ribless grooves 21. The screw urges material to the left, but the material tends to travel to the right between the ribs of the cylinder, whereby a mixing effect is obtained, and the grooves 21 constitute mixing chambers. As shown, the cylinder ribs are formed on a liner 3a bolted to the cylinder 3, but 3 and 3a may be integral. The cylinder is heated or cooled by medium in a helical groove 10 which is closed by a sleeve 9. The temperature of the hopper 6 is controlled by medium in chamber 7. At the forward end of the screw the ribs 18 are duplicated. In modifications : (1), Fig. 4 (not shown), the liner 3a is in two abutting sections, one or both having grooves 21. (2), Fig. 5, the liner is in two abutting sections 27, 36, section 27 having right hand ribs and section 36 right-hand (or left-hand) ribs 40 and left-hand (or right-hand) ribs 39. Two grooves 37, 38 are formed in section 36. (3), Fig. 6 (not shown). This is similar to the Fig. 5 modification except that both lots of ribbing 39 are shown as left-hand: but they may be right-hand. The groove 38 may be in section 27. The grooved parts may be in the form of separate pieces keyed to ribbed sections. (4), Fig. 7, the liner is in three sections, 56, 58, 57, section 58 being keyed to 56 at 60. Sections 56 and 57 are right-hand and section 58 is right-hand or, as shown, left-hand. Grooves 59 are provided as shown in section 58 but may be in one or both of the other sections.