| 摘要 |
The invention relates to a process for producing annular rim cores by filling a polyurethane mixture into an annular tube consisting of plastic film, which is arranged beforehand with its circular ring plane approximately perpendicular in a shaping mould, is left in it during the reaction time of the polyurethane and is removed from it once it has cured. The invention is based on the object of providing a process of the type mentioned at the beginning which ensures in a cost-saving way the production of rim cores which are virtually completely smooth on their outer surface and are therefore endowed with high strength, without air inclusions. This object is achieved according to the invention by rings of film being punched out from a double-ply film web and welded to one another at their outer and inner circumferences to form a tubular ring which, with a filling opening at the top, is laid in the shaping apparatus. The process according to the invention can be applied to all forms of rings in which ring-shaped film tubes are to be filled with polyurethane. <IMAGE>
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