METHOD OF MANUFACTURING MULTILAYER TUBE AND COUPLINGS FOR PIPELINES Russian patent published in 1995 - IPC

FIELD: manufacturing of tubes and couplings for pipelines. SUBSTANCE: method involves supplying polymeric composition into rotating die, with polymeric composition containing dispersed inorganic filler and binder in the ratio filler: resin within the range of 1:2 - 2:1; rotating form at angular speed providing development of centrifugal acceleration within the range of 15-34 g; where g is gravity, till partial separation of resin and filler occurs; introducing fibrous glass into die rotating at predetermined rotational speed in such in such a way that fibrous glass penetrates into at least inner layer, with subsequent repeating of these operations at least once. EFFECT: increased efficiency and high quality of tubes and couplings. 6 dwg