Flexible plastic article and method of manufacturing the same

摘要

A process for making a plastic tube having a variable diameter comprises the following steps. A plastic is obtained. The plastic is fed into an extruder die (216). The plastic is extruded as a tubular molten plastic stream (262) into a mold cavity (218) having an inside diameter greater than the diameter of the tubular molten plastic stream (262). The mold cavity (218) inside diameter varies longitudinally along the length of the mold cavity (218). The tubular molten plastic stream (262) is vacuum expanded radially against the mold cavity inner wall (290). The wall thickness of the tubular molten plastic stream (262) is varied during extrusion at locations longitudinally along the stream (262).