The supramolecular organisation of fibres spun from the melts of crystallising polymers (polyethylene)

An investigation of the supramolecular organisation of isotactic polypropylene (IPP) fibre and of medium-pressure polyethylene film* formed with a positive jet stretch in the crystallising melt has shown that these systems contain fine spherulites flattened relative to the direction of spinning and forming /I-3/. The radius B of the spherulites decreases and the degree of flattening Z i increases with an increase in the ratio of the taking-up speed v 2 of the fibre or film to the me]t feed v I which in all cases practieally coincided with the true jet stretch JS.