A device for positioning in the body of an animal, the device comprising a first portion and a second portion that may be positioned in contact with one other, the first portion and the second portion each comprising a biocompatible conductive thermoplastic material, such that when the device is positioned in the body of an animal and electric current flows from the first portion to the second portion, heat is generated by electrical resistance at the point of contact between the first portion and the second portion so as to melt regions of the first portion and the second portion, and when the electric current is thereafter terminated, the melted regions of the first portion and the second portion re-solidify so that a weld is formed between the first portion and the second portion.

A method for producing a rotor blade of a wind turbine includes the following steps: a) providing at least two different components of the rotor blade, b) placing a resistive element between the components, c) placing a thermoplastic or weldable thermoset resin between the components, d) energizing the resistive element so that the resistive element applies heat to the thermoplastic or weldable thermoset resin to melt or to soften it, and e) joining the components together by means of the molten or softened thermoplastic or weldable thermoset resin.

A device for joining a first component to be welded to a second component to be welded, the joining device having at least one electrically conductive, resistive heating film which comprises a central connection portion and two lateral electrical connection portions. The joining device comprises at least one first electrical insulation member which is positioned in contact with the first face of the heating film, and at least one second electrical insulation member which is positioned in contact with the second face of the heating film, the two electrical insulation members being configured to allow the transfer of heat and to prevent the flow of electric current between the heating film and each component to be welded.

A method for assembling a rotor blade of a wind turbine: a) providing at least two different rotor blade modules that segment the rotor blade along a longitudinal direction thereof, wherein each rotor blade module has a sloped interface section that include a weldable thermoplastic resin and/or a weldable thermoset resin (M, b) providing a resistive element, c) arranging the rotor blade modules and the resistive element in such a way that sloped interface sections face each other and the resistive element is sandwiched between the sloped interface sections, d) energizing the resistive element to apply heat to a weldable thermoplastic resin and/or the weldable thermoset resin to melt or to soften it, and e) joining the sloped interface sections together at a joint by means of the molten or softened weldable thermoplastic resin and/or the weldable thermoset resin to form the rotor blade.

A method for bonding two fiber composite components with each other to form a fiber composite structure includes integrating conductive fibers underneath a bonding surface of at least one of the two fiber composite components, each conductive fiber comprising a carbon fiber coated with an electrically insulating coating, the conductive fibers running along the bonding surface and protruding at least at their ends from the respective fiber composite component; arranging the two fiber composite components against each other at their respective bonding surfaces; passing an electric current through the conductive fibers by electrically contacting the conductive fibers at their protruding ends so that the respective fiber composite component is heated at the bonding surface to a curing temperature; and joining the two fiber composite components with each other at their bonding surfaces via secondary bonding, co-bonding and/or co-curing at the curing temperature, thereby forming the fiber composite structure.

A wind turbine blade is provided including a first and a second blade component connected with each other in an overlap region by thermal welding, the first blade component including a blade shell, a resistive element arranged between the first and second blade components in the overlap region as a remnant of the thermal welding, and an electrically conductive element extending through the blade shell and being electrically connected to the resistive element for supplying power to the resistive element during the thermal welding. The first and second blade components can be joined by thermal welding. Further, the resistive element used as heating element for thermal welding can be heated by electrical current even when the resistive element is difficult to assess from the interior cavity of the blade.

An apparatus for forming a weld between a first portion of a biocompatible conductive thermoplastic material and a second portion of a biocompatible conductive thermoplastic material comprises a first electrode, a second electrode, and a structure for holding said first and second electrodes in opposition to one other with a space therebetween for receiving said first portion and said second portion in contact with one another. The structure is electrically non-conductive and an electrical circuit comprising a power source and a switch arranged such that closure of said switch applies a voltage potential across said first electrode and said second electrode so as to generate heat via electrical resistance, the heat being sufficient to melt regions of said first and second portions.

Composite joints and methods of forming composite joints are presented. A composite joint comprising: a first composite component formed of one of a thermoset material or a first thermoplastic material; a second composite component formed of a thermoset material or a third thermoplastic material; a thermoplastic joining film formed of a second thermoplastic material between the first composite component and the second composite component, the second thermoplastic material different from the thermoset material, first thermoplastic material, and third thermoplastic material; and a carbon conductive layer in the thermoplastic joining film.