The invention provides a sonotrode (100) for welding a material, the sonotrode (100) comprising a welding section (110) configured for contacting the material, wherein the welding section (110) defines a rounded shape (111) in a cross-section parallel to a longitudinal axis (A) of the sonotrode (100), wherein the rounded shape (111) approximates a circular sector (20), wherein the circular sector (20) has a central angle α.sub.c selected from the range of 25°-300°, and wherein the circular sector (20) has a central radius r.sub.c selected from the range of 5-30 mm, and wherein the sonotrode (100) has a width W perpendicular to the longitudinal axis (A) [and to the cross-section], wherein W is selected from the range of 10-100 mm.

A method of welding/joining corrugated pipe segments, an apparatus configured to weld/join corrugated pipe segments, and a method of circulating water are disclosed. The method of welding/joining corrugated pipe segments includes holding or securing an end of each of the corrugated pipe segments with a jig, and welding the ends of the corrugated pipe segments together. The jig includes at least two rings, each configured to receive one of the ends of the corrugated pipe segments, and a brace or connector connected to each of the two rings. The apparatus includes the jig, a welding ring configured to receive the ends of the corrugated pipe segments, a resistive heating coil for heating the welding ring, and a control circuit configured to control a temperature of the resistive heating coil and maintain the temperature of the resistive heating coil once a target temperature is reached.

A protective guard for a hand, finger or thumb includes a first thermoplastic layer heat welded to second thermoplastic layer. The second thermoplastic layer has a thickness that is greater than the thickness of the first thermoplastic layer.

A method of joining overlapping thermoplastic roofing membrane components in which a first thermoplastic roofing membrane component and a second roofing membrane component are positioned in overlapping relationship between a pair of complementary molding surfaces. Heat is generated in a metal substrate and transferred by thermal conduction from the metal substrate to overlapping portions of the first and second thermoplastic roofing membrane components to locally melt and coalesce a portion or more of the thermoplastic material of the first thermoplastic roofing membrane component and a portion or more of the thermoplastic material of the second thermoplastic roofing membrane component. The molten thermoplastic material of the first and second thermoplastic roofing membrane components forms a zone of coalesced thermoplastic material that, upon cooling, forms a solid weld joint.

Disclosed embodiments provide automated fiber placement techniques for fabrication of parts made from composite materials. A peening system with multiple pins provides compaction over irregular surfaces, providing superior performance as compared with traditional compaction rollers. The apparatus that carries out the techniques include a tape dispensing system, a heating system, a peening system, a processor and a memory coupled to the processor. The memory contains instructions that when executed by the processor perform the steps of: dispensing a first ply of thermoplastic composite tape over a mandrel; dispensing a second ply of thermoplastic composite tape on the first ply; and peening the second ply onto the first ply, such that the second ply is bonded to the first ply.

A method for processing a resin member includes: irradiating a first member comprising a resin with first light of a first wavelength that causes electronic excitation of the resin; and irradiating the resin electronically excited through irradiation with the first light with second light of a second wavelength longer than the first wavelength. A wavelength range of the second wavelength is within a wavelength range in which light absorption of the resin increases through electronic excitation of the resin.

A protective guard for a hand, finger or thumb includes a first thermoplastic layer heat welded to second thermoplastic layer. The second thermoplastic layer has a thickness that is greater than the thickness of the first thermoplastic layer.

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 directly joining a polymer to a metal along a joint interface through the formation of C—O—M chemical bonds, where M represents an element in the metal to be joined. The method includes heating the metal to a predetermined temperature above a glass transition temperature of the polymer and less than a flash ignition temperature of the polymer and less than a metal melting temperature of the metal; and applying force to the joint interface of the metal and the polymer to generate intimate atomic contact between the metal and the polymer to create C—O—M chemical bonds between the metal and the polymer.

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.