The present invention relates to a method for evaluating an assembly by welding of parts made of thermoplastic materials, to a test piece and its associated uses, to an installation for implementing this method and to the associated welding system.

A liner bridge for a lined pipeline has bores extending through a tubular wall and terminals fitted in the bores, each terminal being exposed to an inward side of the wall for conducting electricity to an electrofusion element. A sealing interface between each terminal and its surrounding bore has one or more projecting formations of the terminal and at least one complementary formation of the bore engaged with the or each of the projecting formations. The interface can also include a sealing mass in the bore.

A test piece configured for the implementation of a method for evaluating an assembly by welding of parts made of thermoplastic materials, wherein the test piece includes at least two parts based on thermoplastic materials having surfaces to be welded that are at least partially placed opposite one another and respective free surfaces, wherein at least one of the parts is a perforated reference part including at least one perforation.

A heat sink for use in electromagnetic welding of molded parts includes reinforcing fibers embedded in a matrix material, where substantially all of the reinforcing fibers are oriented unidirectionally in a fiber direction, where the reinforcing fibers have a thermal conductivity at room temperature from 100-1000 W/m. K and an electrical resistivity at room temperature from 0.5-10.m, and where the matrix material comprises a high temperature resistant material, optionally a thermosetting resin, having a glass transition temperature Tg above 350 C. The heat sink is used in a method of connecting surfaces of a first molded part and a second molded part by electromagnetic welding. Cooling of the outer surface of the first molded part is provided by the heat sink in direct contact with the outer surface.

A method of manufacturing includes providing a first and second member of a fenestration unit, wherein the first and second members are formed at least partly from a polymeric material. The method further includes providing a weld interface member having a susceptor portion and a cover portion, and at least the susceptor portion includes a susceptor material that is susceptible to induction heating. The cover portion includes a cover material. The method further includes positioning the weld interface member against the first member and the second member at a joint arrangement. The method additionally includes heating, by induction heating, the susceptor material to melt the susceptor portion and the cover portion. Also, the method includes re-solidifying the susceptor portion and the cover portion to attach the first member and the second member, including covering the susceptor material at the joint arrangement with a resolidified portion of the cover material.

A system and method for fusing at least two thermoplastic composite components together may include placing faying surfaces of the thermoplastic composite components in contact with each other, placing a separation layer over and against one of the thermoplastic composite components, and placing a multi-layer composite pressure pad over and in contact with the separation layer. The method may also include placing an activated inductor against the multi-layer composite pressure pad for induction welding the two thermoplastic composite components to each other. The thermoplastic composite components may comprise conductive fibers while the multi-layer composite pressure pad may comprise a first layer and a second layer with non-conductive fibers. The first layer may at least partially melt during induction welding of the two thermoplastic composite components while the second layer may remain rigid throughout this welding.