Importance

Loading Importance Indicators...

Abstract

A platen assembly for simultaneously contact heating surface portions of two polyethylene thick-walled pipes that are to be joined together in a heat bonding process is provided with opposed platen surfaces configured to match the respective pipe surface portions to be heated. The platen assembly is adapted to be placed between the pipe surface portions and an electric heating element in the platen assembly heats the platen surfaces to a temperature sufficient to heat melt the pipe surface portions contacted thereby. The platen surfaces adapted to contact the pipe surface portions are formed with ridges and grooves over their full extent to increase the surface thermal contact between the platen surfaces and the pipe portion surfaces. The ridges and grooves on one platen surface are aligned, respectively, with the ridges and grooves on the other surface to form aligned ridges and grooves in the heat melted pipe surface portions. After the platen assembly is removed, the pipe surface portions are brought together into ridge-to-ridge contact, which leaves openings defined by the respective grooves. As the parts are pressed together the ridges widen as heat melted material flows into the grooves, thereby maintaining an escape passage for air trapped between the pipe surfaces portions being bonded together until completion of the bonding process.

Loading the Abstract Image...

First Claim