A fiber-reinforced composite laminate for use in electromagnetic welding of molded parts of said laminates. The laminate has a plurality of structural layers, each formed of electrically conductive fibers embedded in a thermoplastic matrix. Eddy currents may be induced in the electrically conductive fibers by an electrical conductor that generates an electromagnetic field. The structural layers include a first, a second and, optionally, a third pair of two adjacently positioned structural layers. The first pair has an intermediate layer which allows eddy currents to flow between the two structural layers of the first pair. The second pair has an intermediate layer which prevents eddy currents from flowing between the two structural layers of the second pair. The optional third pair does not have an intermediate layer. The laminate shows efficient heating by an electromagnetic field.

A method for manufacturing a fuel cell assembly includes: arranging an end face of a gas diffusion layer on a placement jig in a state abutting an end face of a resin frame; melting a part of the frame member and causing to penetrate into the gas diffusion layer by pressurizing the projecting part by way of a heat-transfer member, and heating the projecting part via the heat-transfer member by abutting a heating member against of the heat-transfer member; and solidifying the part of the resin frame having penetrated into the gas diffusion layer, in which an abutting position of the heating member relative to the heat transfer member is set in the melting step so that a central axis of the heating member is positioned more to a side of the gas diffusion layer than the central axis of the projecting part.

The present disclosure provides a welded body having a connecting structure formed by welding a first molded body and a second molded body, wherein the first and second molded bodies contain at least one copolymer selected from the group consisting of a tetrafluoroethylene/fluoro(alkyl vinyl ether) copolymer and a tetrafluoroethylene/hexafluoropropylene copolymer, and wherein the connecting structure has a liquid contact surface to be in contact with a liquid having a solubility parameter of 14 to 35 (MPa).sup.1/2, a welded part formed in the connecting structure is not exposed to the liquid contact surface, and the number of particles of 30 nm or larger to be eluted from the liquid contact surface in the connecting structure is 1,000 particles/ml or less.

A method for joining moulded parts by electromagnetic welding. A joining inductor is moved along contact surfaces of the moulded parts, generating an electromagnetic field in an induction-sensitive component of the moulded part(s) to heat a thermally activated coupling means of the moulded part(s) to above a melting temperature of the coupling means. The strength of the electromagnetic field suitable for joining is determined by previously moving a sensing inductor along the contact plane, generating a relatively weak electromagnetic field to slightly heat the thermally activated coupling means to a sensing temperature, measuring the field strength generated by the sensing inductor in the moulded part(s), determining a discrepancy between the measured field strength of the sensing inductor and the field strength suitable for joining, and adjusting the field strength suitable for joining to close the discrepancy. A device for carrying out the method.

A method for joining moulded parts by electromagnetic welding. A joining inductor is moved along contact surfaces of the moulded parts, generating an electromagnetic field in an induction-sensitive component of the moulded part(s) to heat a thermally activated coupling means of the moulded part(s) to above a melting temperature of the coupling means. The strength of the electromagnetic field suitable for joining is determined by previously moving a sensing inductor along the contact plane, generating a relatively weak electromagnetic field to slightly heat the thermally activated coupling means to a sensing temperature, measuring the field strength generated by the sensing inductor in the moulded part(s), determining a discrepancy between the measured field strength of the sensing inductor and the field strength suitable for joining, and adjusting the field strength suitable for joining to close the discrepancy. A device for carrying out the method.

Provided a composite material forming method capable of easily using a composite material that is formed by causing a resin to react in a state where it is joined to another member; and a composite material. The composite material forming method includes a first material preparation step (magnetic field circuit forming material preparation step S11), a second material preparation step (magnetic field circuit non-forming material preparation step S12), a material assembly step S13, and a first heating step (magnetic field heating step S14). In the first material preparation step, a first material including a first resin is prepared. In the second material preparation step, a second material including a second resin is prepared. In the material assembly step S13, the first material and the second material are assembled to each other.

Apparatuses, methods, and systems are disclosed for attaching structures. One system includes: a device having a first structure attached to a second structure; a first polymer coupled to the first structure, wherein the first polymer has a first temperature profile and a first shape; and a second polymer coupled to the second structure. The second polymer has a second temperature profile and a second shape. The second shape interlocks the first shape. The first polymer and the second polymer secure the first structure to the second structure in response to the first polymer and the second polymer being in a first temperature range. The first polymer and the second polymer release the first structure from the second structure in response to the first polymer and the second polymer being in a second temperature range different from the first temperature range.

A system and method for thermoplastic composite welding comprising a cooling means and a heat source. The cooling means cools a heat-side laminate so as to create a thermal gradient in the heat-side laminate. The heat source heats the heat-side laminate after the cooling step is initiated but before the thermal gradient dissipates so that a first side of the heat-side laminate closer to the heat source does not deform as faying surfaces of the heat-side laminate and another laminate farther away from the heat source are welded together.

Apparatuses, methods, and systems are disclosed for attaching structures. One system includes: a device having a first structure attached to a second structure; a first polymer coupled to the first structure, wherein the first polymer has a first temperature profile and a first shape; and a second polymer coupled to the second structure. The second polymer has a second temperature profile and a second shape. The second shape interlocks the first shape. The first polymer and the second polymer secure the first structure to the second structure in response to the first polymer and the second polymer being in a first temperature range. The first polymer and the second polymer release the first structure from the second structure in response to the first polymer and the second polymer being in a second temperature range different from the first temperature range.

A method and a device for heat sealing multiple plies of a laminate from which gable top packaging can be produced, wherein the laminate has a carrier layer made of electrically non-conductive material and a sealing layer made of thermoplastic material on at least one surface of the laminate. To heat seal multiple plies of a laminate in a high-frequency alternating electric field, the alternating electric field is generated by a first lead of an HF voltage supply in a first sub-region of the sealing region and is generated by a second lead of the HF voltage supply, differing from the first lead, in at least a second sub-region of the sealing region, so that a different heat distribution is obtained over the sub-regions of the sealing region.