| 摘要 |
1,182,274. Screw mixers. NYPEL Inc. 3 April, 1967 [29 July, 1966], No. 15184/67. Heading B1C. [Also in Division B5] Rods, tubes or core coatings of thermoplastic material plus an abrasive filler are made by plasticizing thermoplastic material using a first screw impeller and heater system 16, 18, forwarding the plasticized material to a second impeller and heating system 32, 36, where the filler is added from a vibrated hopper 42 to be thoroughly admixed with the plasticized material, and extruding the mix through a suitable die head 50. As shown the screw systems are at right angles to one another with screw 16 linked to screw 32 via a bearing 30, hopper 42 is provided with a vibrator 46, and the extrudate is in the form of rods 62. Screw 32 is capable of a higher output than screw 16. Both hoppers 22 and 42 may have a valve member such as (26) Fig. 2 (not shown), and the relative rates of feed therefrom may be controlled automatically. Thermoplastic materials specifically mentioned are nylon, polypropylene, polycarbonate, acetals, acrylics, polyethylene, polyurethane, PVC and combinations of nylon and polyester. Abrasive fillers mentioned are aluminium oxide, silicon carbide, diamond dust, ceramic or asbestos particles or chopped-glass fibres. |
