Yu. M. Budnitskii

Compaction of Reactor Powders of Ultrahigh Molecular Weight Polyethylene

In previous publications (refs. 1 and 2) an examination was made of features of the processing of ultrahigh molecular weight polyethylene (UHMWPE) by die stamping and the properties of the articles produced. Setting up of the cost-effective production of articles from UHMWPE by the given method is being held back by the need for preliminary production of semiproducts exposed to strain. Owing to features of the given material, its processing by high-performance methods is difficult and the production of semiproducts requires the creation of special technology. The advantages of forming methods in the solid state are largely lost in this case. In view of this, the present work is devoted to the development of a process for the production of compacted semiproducts. The semiproduct for subsequent die stamping should have a shape similar to the configuration of the article and have an identical mass if the process is to be waste free. An analysis of published data showed the possibility of producing such semiproducts from UHMWPE by sintering, which is used to produce articles from difficult-to-process materials (refs. 3 and 4). Sintering is the process of the transition during heating of powder compacted to different degrees into a solid or porous substance. The process of producing articles from polymers by sintering includes the following stages: