Apparatus for coating plastic pipe

摘要

In certain composite plastic pipe manufacturing operations it is necessary to provide an adhesive coating between the core pipe and the fiber glass reinforced layer, especially if the core pipe is a thermoplastic and the fiber glass reinforced material is a thermoset resin. In the disclosed coating apparatus (2), a coating chamber (4) is provided with seal means (20) at a first wall (14) and seal means (22) and a second wall (16), preferably a second chamber (40) is provided with a similar seal means (44). The coating chamber is maintained in a filled condition with a liquid coating material via a circulating pump (48) and associated reservoirs (34, 36, etc.). Rollers (62, 64) maintain the pipe sections in correct positional relationship with the coating apparatus. During operation, the pipe sections pass through the coating chamber and the second chamber providing a uniformly thin coating of adhesive material to the outside diameter of the pipe while minimizing loss of the coating material and volatization of the solvent component of the coating material in its liquid state.