The invention relates to a process for the production of at least two-layer thermoplastic sheets via thermal welding of at least one thinner thermoplastic sheet with density (D1) and of at least one second thinner thermoplastic sheet with density (D2), where the density (D1) of the first thinner thermoplastic sheet is smaller than the density (D2) of the second thinner thermoplastic sheet. The process introduces at least one first heating element and at least one second heating element along mutually offset planes between the two thinner thermoplastic sheets, where the surfaces of the thinner thermoplastic sheets do not touch the surfaces of the heating elements. The first heating element transfers a quantity of energy (E1) to the surface of the first thinner thermoplastic sheet, and the second heating element transfers a quantity of energy (E2) to the surface of the second thinner thermoplastic sheet, where the quantity of energy (E1) is smaller than the quantity of energy (E2).

A method of manufacturing a heat exchanger array that includes stacking a plurality of heat exchanger units in an aligned configuration with respective first ports of the plurality of heat exchanger units aligned. The method can further include generating heat in the first coupling elements at the same time and at a temperature sufficient to generate a first plurality of respective couplings between adjacent sheets of adjacent heat exchanger units about adjacent first ports and without a coupling being generated between the first and second sheets of a given heat exchanger unit.

To achieve universal welding of thermoplastic workpiece parts with simple equipment, an infrared light transmission welding method is disclosed in which simple polychromatic, incoherent infrared light is generated by a simple infrared light source and is directed through a first workpiece part to a weld point for the purposes of connection to a second workpiece part. In particular, the infrared light is directed through a transparent bracing element.

Installation fittings for use with induction weldable pipe connectors for assembling multi-layer pipe fluid distribution systems. Induction welding pipe connectors including a major central pipe connector section and a minor lateral pipe connector section pair having reduced thickness relative to the major central pipe connector section. Induction welding pipe connectors with integral solder flow barrier for assembling fluid distribution systems. Electromagnetic induction coil reverse action pliers for use with induction weldable pipe connectors for assembling fluid distribution systems.

A method of manufacturing a heat exchanger array that includes stacking a plurality of heat exchanger units in an aligned configuration with respective first ports of the heat exchanger units aligned. The heat exchanger units can include a first and second sheet coupled together to define an cavity between the first and second sheets; the first port at a first end of the heat exchanger unit defined by the first and second sheets; and a second port at a second end of the heat exchanger unit defined by the first and second sheets. The method further includes stacking the plurality of heat exchanger units in an aligned configuration with the first ports of the plurality of heat exchanger units aligned and generating a first plurality of respective couplings between adjacent sheets of adjacent heat exchanger units about adjacent first ports. The coupling can be generated by an adhesive.

A method of joining workpieces includes the steps of bringing a first workpiece and a second workpiece together, induction heating a susceptor material, and pressing the workpieces together. Each workpiece may include a thermoplastic material, and the workpieces are brought together at a joint interface so that a protrusion of the first workpiece is aligned with a receptacle of the second workpiece. The susceptor material is in contact with the thermoplastic material of the first workpiece during heating such that the thermoplastic material of the first workpiece softens. The step of pressing is performed while the thermoplastic material of the first workpiece is softened, thereby reshaping the first workpiece where the susceptor material is in contact with the thermoplastic material of the first workpiece. The protrusion is deformed to form an interlock with the receptacle at the joint interface.

Installation fittings for use with induction weldable pipe connectors for assembling multi-layer pipe fluid distribution systems. Induction welding pipe connectors including a major central pipe connector section and a minor lateral pipe connector section pair having reduced thickness relative to the major central pipe connector section. Induction welding pipe connectors with integral solder flow barrier for assembling fluid distribution systems. Electromagnetic induction coil reverse action pliers for use with induction weldable pipe connectors for assembling fluid distribution systems.

Laser transparent compositions that may be black in color. The laser transparent compositions may include a matrix material that includes a polypropylene, a dye system that includes one, and optionally two or more, polar organic compounds, a plurality of glass fibers, and a UV stabilizer. Methods of laser welding, which may include irradiating a laser absorbing composition that contacts a laser transparent composition at an interface.

Installation fittings for use with induction weldable pipe connectors for assembling multi-layer pipe fluid distribution systems. Induction welding pipe connectors including a major central pipe connector section and a minor lateral pipe connector section pair having reduced thickness relative to the major central pipe connector section. Induction welding pipe connectors with integral solder flow barrier for assembling fluid distribution systems. Electromagnetic induction coil reverse action pliers for use with induction weldable pipe connectors for assembling fluid distribution systems.

A method of joining workpieces includes the steps of bringing a first workpiece and a second workpiece together, induction heating a susceptor material, and pressing the workpieces together. Each workpiece may include a thermoplastic material, and the workpieces are brought together at a joint interface so that a protrusion of the first workpiece is aligned with a receptacle of the second workpiece. The susceptor material is in contact with the thermoplastic material of the first workpiece during heating such that the thermoplastic material of the first workpiece softens. The step of pressing is performed while the thermoplastic material of the first workpiece is softened, thereby reshaping the first workpiece where the susceptor material is in contact with the thermoplastic material of the first workpiece. The protrusion is deformed to form an interlock with the receptacle at the joint interface.