Thermoplastic induction-welding systems

摘要

A flexible ferromagnetic strip is used to induction-weld seams in polymer pipes. The strip is a blend of strontium ferrite, a surfactant, and an LDPE binder. A process to produce the profile is to mix the ingredients together followed by granulation and extrusion or calendering. The strip is used in conjunction with an induction coil sized to fit over a polymer pipe coupling containing the strip and separate segments of polymer pipe. The strip is heated by induction current induced by an electromagnetic field generated by the coil. The heated strip causes the polymer pipe segments to be thermoplastically welded together.

主权项

1. A system for thermoplastic induction welding of polymer pipes, comprising:
a flexible ferromagnetic strip configured to fit within a coupling of a polymer pipe, the flexible ferromagnetic strip comprising at least one ferromagnetic material combined with a polymer material having at least one surfactant selected to allow a higher loading of the ferromagnetic material in the polymer material while maintaining flexibility; an electromagnetic induction coil configured to surround said coupling; and a power supply electrically connectable to said electromagnetic induction coil and configured to cause said coil to generate an electromagnetic field upon energizing thereof by said power supply, whereby a flow of current is induced in said ferromagnetic strip to heat said strip, resulting in thermoplastic welding of separate polymer pipe segments located within said coupling.