| abstract |
A method of manufacturing polymethylene filaments, wherein polyoxymethylene having the molecular weight from 30,000 to 100,000 and containing stabilizing additives in a quantity from 0.1 to 3.0 per cent of the weight of the polyoxymethylene is subjected to thermal treatment at a temperature from 100 DEG to 150 DEG C. and residual pressure from 1 to 100 mm mercury to attain constant weight. The thus thermally treated polyoxymethylene is melted at a temperature from 170 DEG to 230 DEG C., whereafter the melt is forced through the orifices of an extrusion nozzle. The jets of the melt, leaving the orifices of the extrusion nozzle, are cooled at a temperature from 70 DEG to 169 DEG C. After the cooling the obtained filaments are drawn at a temperature from 120 DEG to 165 DEG C. to a length exceeding from 7 to 14 times the initial length. |