| 摘要 |
In the case of a process for producing pourable spherical-segment-shaped packing material particles (18) made of plastic which have an external convex and an internal concave surface, the plastic material is mixed with additives, such as bubble forming agents, coloring pigments and similar agents. The plastic material is fed, by means of a feeding funnel (17) into an extruder (14) through an opening in a bush (13) surrounding the extrusion screw. The plastic material plasticizes over the course of the extruder (14) and, because of the difference in speed existing over the cross section of the mass, comes out of an opening (15) in the die with a bent surface. The plastic material is cut off directly at the opening (15) of the die and before any considerable expansion has taken place. Before the processing of the plastic granules in the extruder (14) a bubble-forming agent (nucleation agent) is applied to their surface in a drum (5). |
