NEW FLEX RING DIES IMPROVE THE THICKNESS TOLERANCES OF PIPES AND THUS SAVE MONEY

摘要

Conventional pipe dies consist of a solid mandrel and a solid outer ring. With such dies the thickness distribution in pipes can only be influenced by centring the die. Two thick regions situated opposite each other can not be fought. This is possible when you retrofit a multi-walled Flex Ring sleeve into the outer ring of a pipe die. Similar to the well proved flex lip technique in flat film production the Flex Ring technology allows for a locally limited adjustment of the flow channel gap. Even the thickness distribution of single layers in coextruded pipes can be fine tuned. The new technology which overcomes by far existing limitations to the pipe production process will be explained and results obtained with the new generation of pipe dies will be presented.