| 摘要 |
1,041,287. Worm extruders. FARBENFABRIKEN BAYER A.G. Aug. 4, 1964 [July 31, 1963], No. 31208/64. Addition to 924,108. Headings B5A and B5B. A screw or worm extruder for melting thermoplastic synthetic resin, especially polyamides or polyurethanes, comprises a screw housing 2 provided with a heated melting zone 5, a tempering zone 6 preceding the heated melting zone in the direction of flow of the material, and a melt supply zone 8 after the melting zone, the screw housing being constructed in the region of the tempering zone as a unilaterally secured torsion member secured to the exterior of which is a lever 14 serving, in the operation of the screw, to actuate the switching-on and off contact 15 for the drive of a metering device (not shown) for the material, the screw 3 ending with its threads at the outlet end of the tempering zone 6 of the housing whilst a stirrer 16 or 17 is arranged in the melting zone. In Fig. 1, the stirrer 16 is a paddle. In Fig. 3, the stirrer 17 is a fork between the prongs of which an immersion heater is fixed. In operation, if for example, the rate of feed of material rises in relation to the rate of outflow of melt, the position of the solid-liquid interface in the worm housing will shift towards the feed aperture, increasing the torque and changing the torsion of the screw housing. By arranging that the screw ends with its threads at the outlet of the tempering zone a considerable increase in the melt output can be achieved while accurately maintaining the quantity of melt removed. |
