A method of resistive implant welding carbon fiber thermoplastic composites which includes providing at least two portions of a component formed with carbon fiber material, the at least two portions of the component each have a welding surface where the at least two portions of the component are welded together. One or more conductors of copper or aluminum mesh material positioned between the welding surface of the two portions. The method includes a forming tool having at least two portions capable of moving between an open position and a closed position. The forming tool has a welding region with non-conductive metal surface areas where electric current is selectively applied to facilitate the welding together of the at least two portions of the component. The forming tool has forming regions with conductive surfaces where the two components are shaped.

A method for resistance welding of two fiber-composite components to give a fiber-composite structure includes arranging conductive fibers within a jointing region of the two fiber-composite components, where each conductive fiber includes a carbon fiber with an electrically insulating coating. An electric current is passed through the conductive fibers to heat the jointing region to a welding temperature and melt the fiber-composite components in the jointing region. The jointing region is hardened in a manner that bonds the two fiber-composite components by way of the jointing region to give the fiber-composite structure.

An apparatus for thermally joining thermoplastic fiber composite components includes a pressurization arrangement for jointly covering, at least in a region of a joining zone, thermoplastic fiber composite components to be joined and applying pressure to the thermoplastic fiber composite components to press the thermoplastic fiber composite components against one another, at least in the joining zone, the pressurization arrangement being flexible, at least in some section or sections. A welding device is configured for welding the fiber composite components in the joining zone during pressurization. The pressurization arrangement and welding device are configured to weld the thermoplastic fiber composite components in a pressurized state in the joining zone. The pressurization arrangement is configured to maintain pressurization independently of the welding device until the joining zone solidifies. A cover is also disclosed for a pressurization device for thermally joining thermoplastic fiber composite components.

A method for resistance welding of two fiber-composite components to give a fiber-composite structure includes arranging conductive fibers within a jointing region of the two fiber-composite components, where each conductive fiber includes a carbon fiber with an electrically insulating coating. An electric current is passed through the conductive fibers to heat the jointing region to a welding temperature and melt the fiber-composite components in the jointing region. The jointing region is hardened in a manner that bonds the two fiber-composite components by way of the jointing region to give the fiber-composite structure.

Disclosed herein is a method for connecting first (110) and second (120) plastic pipes. The method includes: placing an end of the second plastic pipe (120) on a target portion of the first plastic pipe (110) that is intended to form a connection hole (111), the end of the second plastic pipe (120) being provided with an arch-shaped heating element (130) made of conductive plastic material, electric connection terminals (140) disposed in the heating element (130) on opposite sides of the target portion, and a cover (121) covering at least an outer surface of the arch-shaped heating element (130); supplying power to the electric connection terminals (140) to heat the arch-shaped heating element (130) so that the second plastic pipe (120) is fused to the first plastic pipe (110); and forming the connection hole (111) in the cover (121), the arch-shaped heating element (130) and the side surface of the first plastic pipe (110), so that the first plastic pipe (110) and the second plastic pipe (120) communicate with each other.

A method and an apparatus for welding a first object to a second object, wherein the first object is produced from a thermoset and comprises a thermoplastic material outer layer, wherein the second object comprises at least one thermoplastic material outer layer. In addition, a layer of carbon nanotubes is applied to the thermoplastic material outer layer of the first object, and the second object is placed onto the first object. At least some of the thermoplastic material outer layer of the second object lies atop the applied layer of carbon nanotubes. In addition, a potential is applied to the layer of carbon nanotubes, such that an electrical current flows through the carbon nanotubes, wherein the thermoplastic material outer layer of the first object and the thermoplastic material outer layer of the second object are heated and are welded to one another.

A method for laser welding of non-transmissive composite materials includes: forming an energy channel having an end opening and extending through a first part made of a first material; and welding a second part made of a second material to the first part via laser heating of the materials of the first and second parts proximate to the end opening of the energy channel such that the materials of the first and second parts fuse to form a weld nugget, attaching the first part to the second part.

A resistance spot welding method can be used to join polymeric and metallic workpieces together and includes the following steps: (a) placing an electrically conductive coating between a polymeric workpiece and a metallic workpiece, wherein the metallic workpiece has a textured surface facing the polymeric workpiece; (b) piercing the polymeric workpiece with first and second electrically conductive pins of a welding electrode assembly; (c) applying electrical energy to the first and second electrically conductive pins so that an electrical current flows through the first electrically conductive pin, the electrically conductive coating, and the second electrically conductive pin in order to at least partially melt the polymeric workpiece and the electrically conductive coating, thereby forming a weld pool; and (d) cooling the weld pool to form a solid weld nugget in order to establish a mechanical interface lock between the solid weld nugget and the textured surface.

Electric welding coupler for the welding of pipes made of thermoplastic material or other weldable plastics comprising a cylindrical body made of thermoplastic material or other weldable plastics, containing at least one welding element, wherein the welding element is arranged close to the inner diameter of the cylindrical body, wherein the welding element forms at least two welding zones, a contact for feeding the electric current and at least one cavity, wherein the cavity is arranged in the cylindrical body, wherein a reinforcing ring is arranged around the outer circumference respectively outer diameter of the cylindrical body.

The invention provides improvements to electrofusion fitting methods that allow for continuity and repeatability of welds between an electrofusion fitting and a pipe lining (or stand-alone pipe). An electrofusion fitting for joining sections of lined pipe has heating elements configured to create at least one weld between the electrofusion fitting and a pipe lining, however prior to the weld step taking place the electrofusion fitting is heated and expands accordingly to ensure contact with the pipe lining. Preheating the electrofusion fitting also provides a predetermined starting temperature for the fitting and the lining which results in improved fusion cycle reliability. Furthermore, the need for clamps or support frames to support the electrofusion fitting in situ is removed, with corresponding reductions in cycle times, complexity, and hence cost.