KUNSTSTOFFROHR MIT IN SEINER WANDUNG AUSGEBILDETEN LAENGSKANAELEN UND VERFAHREN ZU SEINER HERSTELLUNG

摘要

This invention relates to a method of making a tube of thermoplastic material, comprising longitudinal channels of circular cross-section and having such wall stresses that, after axially cutting the tube, the edge parts along the cut edge overlap each other for less than 8% of the outer circumference of the tube.