Patent ID: 7524177
Filing Date: 2009-04-28
Classification: B29C,B29L

Abstract:
1. A pipe molding system for producing plastic pipe, said system including a plurality of moving first mold block sections and second moving mold block sections, the first mold block sections closing with the second mold block sections to form a moving mold tunnel, means for feeding molten plastic to the first and second mold blocks sections to form the plastic pipe, and a cooling plug for setting the plastic pipe in the moving mold tunnel, the plastic pipe having a pipe wall with a first wall portion which travels over and is in contact with said cooling plug and a second wall portion which travels over and is spaced outwardly away from said cooling plug, the first wall portion transferring heat directly to said cooling plug; said system including a first temperature control to prevent excessive plug cooling as the first wall portion travels over the cooling plug, said system including a second temperature control which operates to replace the first temperature control in preventing the excessive plug cooling as the second wall portion of the pipe wall travels over the cooling plug.