There is described a method for forming a tube (3) of a web (4, 4) of packaging material comprising the steps of advancing the web (4) of packaging material along a web advancement path (P), overlapping a first lateral edge (19) of the web (4, 4′) of packaging material with a second lateral edge (20) of the web (4, 4) of packaging material for obtaining a longitudinal seam portion of the tube (3) and fusing at least an internal outer surface (34) of the first lateral edge (19) and an external outer surface (37) of the second lateral edge (20) with one another for longitudinally sealing the seam portion of the tube (3). The step of fusing comprises at least the substeps of directly heating the external outer surface (37) of the second lateral edge (20) and heating by contact the internal outer surface (34) by establishing contact between the internal outer surface (34) and the directly heated external outer surface (37).

An assembly is provided for induction welding. This assembly utilizes a heat shield (e.g., a mica heat shield) with a recess. An induction welding coil may be disposed within this heat shield recess during induction welding operations. The wall thickness of the heat shield within the recess may be reduced to enhance heat transfer to a workpiece during induction welding operations. Members may engage the heat shield on opposite sides of the recess (and that have an increased wall thickness) to support both the heat shield and the workpiece during induction welding operations, during which a biasing force may be exerted on both the heat shield and workpiece.

During a manufacturing method, an induction welder is provided that includes a concentrator and a coil. The concentrator includes a receptacle and a face surface. The receptacle projects vertically into the concentrator from the face surface to an end of the receptacle. The receptacle extends laterally within the concentrator between opposing sides of the receptacle. The receptacle extends longitudinally within the concentrator along a centerline. The coil is seated and extends longitudinally along the centerline within the receptacle. A first thermoplastic body arranged with a second thermoplastic body are provided. The first thermoplastic body is located vertically next to the face surface. The first thermoplastic body is induction welded to the second thermoplastic body. The induction welding includes: generating an electromagnetic field with the coil; and concentrating the electromagnetic field with the concentrator onto a region of the first thermoplastic body.

During a manufacturing method, an induction welder is provided that includes a concentrator and a coil extending through a receptacle in the concentrator. The receptacle projects into the concentrator from a face surface of the concentrator. A first thermoplastic body arranged with a second thermoplastic body are provided. The first thermoplastic body is located next to the face surface. The first thermoplastic body is induction welded to the second thermoplastic body to provide a weld seam between the first thermoplastic body and the second thermoplastic body. The concentrator extends along a portion of the weld seam. The induction welding includes: generating an electromagnetic field with the coil; and concentrating a portion of the electromagnetic field with the concentrator onto a region of the first thermoplastic body.

A system and method for welding thermoplastic components is provided. The system includes a component positioning system and a welding subsystem. The component positioning system includes a trailing force applicator having first and second lateral side trailing force applicators disposed on opposite lateral sides of a weld line. The welding subsystem is configured to weld the thermoplastic components together at a weld zone. The first and second lateral side trailing force applicators are laterally spaced apart from the weld zone, and at least a portion of the first and second lateral side trailing force applicators are disposed aft of the weld zone. During welding the first and second lateral side trailing force applicators and a welding subsystem probe are moved relative to the thermoplastic components, or vice versa.

Methods and apparatus' for induction welding a first workpiece to a second workpiece at a welding region may include a metallic strip. The metallic strip may be a mesh. The properties of the metallic strip, such as, for example, pore size, thickness, and density, may be configured to conduct heat uniformly across the welding region and prevent eddy current formation across a workpiece. The metallic strip may be embedded in a workpiece or may be fixed to an induction welding tool that acts on the welding region during induction welding. A removable polymer tape may be disposed between a workpiece and a metallic strip fixed to an induction welding tool. The workpieces may be thermoplastic composite structures and thermoplastic composite stiffeners in aircraft structures.

Systems and methods for induction welding a stiffener to a thermoplastic composite structure using a removeable metal mask to reduce excess heat along the edges of the stiffener generated from an electromagnetic field of an induction welding tool.

A laser welding system for joining first and second thermoplastic workpieces, and including a clamp, an actuator, and a laser source. The clamp includes first and second clamping structures positioned together to engage opposite sides of the workpieces when they adjoin each other. The first clamping structure has a non-flat or irregular surface, facing the first workpiece. The actuator causes the clamping structures to press the first and second workpieces together. The laser source applies laser radiation having a wavelength of 2 microns toward the workpieces to be joined, while they are pressed together by the clamp, to melt irradiated portions of the workpieces to one another. The first clamping structure transmits substantially all of the energy of the laser radiation through the material. The first workpiece has a non-flat or irregular surface facing the first clamping structure, which substantially conforms with the surface of the first clamping structure.

An elastic nonwoven material includes a first non-woven fabric including a plurality of rows. Each row has a plurality of adjacent bonds formed therein. The elastic nonwoven material also includes a first elastic strand entrapped between a first pair of adjacent bonds within a first row of the plurality of rows, and a second elastic strand entrapped between a second pair of adjacent bonds within the first row. A third pair of adjacent bonds within the first row is free of elastic material therebetween and is located between the first pair of adjacent bonds and the second pair of adjacent bonds.

A laminate tube with an invisible longitudinal overlapped side seam formed from overlap welding an edge of one margin of a laminate sheet comprising an outer plastic layer (A), a barrier layer (B), and an inner plastic layer (C) of the same material type as the outer plastic layer (A) to the other edge of the opposite margin of the laminate sheet, such that an inner surface of the laminate tube has a hump in a overlapped region, while an outer surface of the laminate tube is smooth without a hump in the overlapped region; and a process for manufacturing the laminate tube by a laminate tube manufacturing machine. The laminate permits fracture-proof welding of longitudinal margins of said laminate to give a continuous tube which is suitable for manufacturing of high-quality plastic tubes, high-quality plastic bags and the like.