Synthetic tube with longitudinal channels in wall - with channel centres equidistant from inner and outer surfaces of tube wall

摘要

Tube of synthetic material, with optimum properties w.r.t. rigidity and dimensions, comprises in its wall longitudinal channels of circular cross-section arranged regularly over the whole circumference. The centres of the circles which form the cross-section of the channels are located along a circumference of which the distance from the outer surface of the tube is at most equal to the distance from the inner surface. The latter distance may be greater, with a difference of 10-20%. With a greater distance between the circumference and the inner surface, the tube has even more optimal properties of rigidity.