Method for manufacturing bearings or other anti-friction elements formed of lubricant contained polyacetal

A method of making bearings or other anti-friction elements characterized by comprising the steps of uniformly mixing at the normal room temperature polyoxymethylene or copolymers of trioxane and ethylene oxide having the bulk factor of 2 - 8 in the starting material, with 2 to 12 wt % of a lubricant which is in a liquid state at normal room temperature or the melting point of the polymer or copolymer to form a molding composition, the lubricant being from the group consisting of a mineral oil and a synthetic lubricant oil which are in a liquid state at the normal room temperature;

• or from paraffins, a higher fatty acid or a higher fatty acid ester, which are in a solid state at the normal room temperature but in a liquid state at the melting point of the material being processed;
• and grease which is in a jelly state at the normal room temperature;
• and molding the resultant molding composition to form the element by use of a screw type injection or extrusion molding machine, the temperature of the feed section of the cylinder of the machine which has been controlled to that of 40 - 75% of the melting point of the material used, and having the cylinder temperature controlled to about 65.degree. - 120.degree. C in the feed section, about 120.degree. - 190.degree. C in the compression section, and about 170.degree. - 200.degree. C in the metering and the nozzle sections of the cylinder.