| 摘要 |
733,585. Mixing-appliances. PASQUETTI, C. July 30, 1953 [Oct. 2, 1952], No. 21200/53. Class 86. [Also in Group V] A screw press for plastic material such as thermoplastic resins and compositions comprises mixing-chambers 3a, 3b, 3c, 3d communicating with each other via openings 6a, 6b, 6c, and housing pairs of side-by-side intermeshing screws 4a, 4b, 4c, 4d driven by mechanisms, shown diagrammatically at 9a, 9b, 9c, 9d at different speeds in each chamber, either by independent motors with variable transmission or by one motor and gear transmission. The material is fed in via hopper 5 and in opposite directions through alternate chambers to the extrusion die 7. The screws may be either constant in diameter and gradually reduced in pitch, with consequent variation in the number of threads, or each pair of screws may be of constant screw pitch and number of threads smaller than those of the preceding pair of screws. Each screw may alternatively be subdivided into several sections decreasing in diameter. A hole 11 is formed in bushing 10 supporting screws 4 to discharge material reaching the clearance between parts 8 and 10. |
