Described herein are polyphenylene sulfide (“PPS”) polymers having excellent transparency to infrared (“IR”) radiation. It was surprisingly discovered that PPS polymer composition including PPS polymers having a selected metal ion (Ca, K, and Mg) concentration at least 400 parts per million by weight (“ppm”), had significantly increase IR transparency, relative to corresponding PPS polymer compositions including a PPS polymer having a selected metal ion concentration less than 400 ppm. Additionally, described herein are methods for laser welding the PPS polymer compositions.

A process of constructing an air tight and water tight seam, comprising cutting a sheet of selected material into two or more panels, sealing the panels at respective selected edges using an ultrasonic machine to form a seam, overlaying the seam with a tape made of the same selected material, and sealing the tape and seam using a radio frequency (RF) welding machine.

In an adhesive selection method, test data is acquired by subjecting an adhesion complex, obtained by integrally bonding one material and an other material that are heterogeneous using an adhesive, to a shear test, in which a tensile shear load is applied to the adhesion complex in a direction that causes shear deformation in the adhesive, until adhesive failure takes place. Based on the test data, a plurality of two- or three-dimensional FEM analysis models of the adhesion complex with varied adhesives are constructed. On each of the analysis models, a simulation is performed in which a tensile shear load is applied. Based on the stresses and locations of the stresses generated in each of the analysis models in the course of the, the adhesive for binding one member made of the one material and the other member made of the other material is selected from among the adhesives.

A bonding method for bonding an adherend with a high-frequency dielectric heating adhesive sheet is provided. The adherend includes a fluorine-containing surface at least containing fluorine on a surface thereof. The high-frequency dielectric heating adhesive sheet includes a high-frequency dielectric adhesive layer including a thermoplastic resin and a dielectric filler. A surface free energy of the high-frequency dielectric adhesive layer is in a range from 15 mJ/m.sup.2 to 30 mJ/m.sup.2. A melting point of the high-frequency dielectric adhesive layer is in a range from 110 degrees C. to 300 degrees C. The bonding method includes bringing the fluorine-containing surface of the adherend into contact with the high-frequency dielectric adhesive layer and applying a high-frequency wave to the high-frequency dielectric adhesive layer to bond the high-frequency dielectric heating adhesive sheet to the fluorine-containing surface.

A molded article of a carbon fiber composite material includes at least carbon fibers and a resin composition. The molded article of a carbon fiber composite material is characterized in that the surface roughness Ra thereof is 0.01-2 μm and in that the tensile shear adhesive strength (F0) thereof when a metal has been adhered to the surface thereof via an adhesive layer that contains an epoxy compound and is 0.1-3 mm thick is 10-40 MPa.

A high-frequency dielectric heating adhesive sheet includes an adhesive layer. The adhesive layer contains a thermoplastic resin having a reactive site, a dielectric filler that generates heat upon application of a high-frequency electric field, and a silane coupling agent.

An adhesive-based joint includes a first adherend, a second adherend, an adhesive layer located between the first adherend and the second adherend, and plural strip parts of a low adhesive material embedded into the adhesive layer. The low adhesive material has an adhesion with the adhesive layer lower than an adhesion between the first or second adherend and the adhesive layer.

A method for optimizing a welding process to produce a weld joint having a predetermined strength includes measuring a plurality of melt layer thicknesses of weld joints for a plurality of sample assemblies formed by the welding process, measuring a plurality failure loads of weld joints for the plurality of sample assemblies, each of the measured plurality of failures loads being associated with one of the measured plurality of melt layer thicknesses, selecting a first failure load from the plurality of measured failure loads responsive to determining that the first failure load corresponds to a predetermined weld strength, and selecting a first melt layer thickness from the plurality of measured melt layer thicknesses that is associated with the selected first measured failure load.

A metal-resin joining method of joining a metal member to a composite material member including a fiber reinforced plastic composite material includes an applying step of applying a first adhesive that is a thermosetting adhesive to a first region between the metal member and the composite material member, and applying a second adhesive that is a thermosetting adhesive to a second region between the metal member and the composite material member, a provisional bonding step of irradiating a first irradiation region of the metal member opposed to the first region with a laser light, and heating and curing the first adhesive to provisionally bond the metal member and the composite material member together, and a main bonding step of curing the second adhesive after the provisional bonding step to bond the metal member and the composite material member together.

In the vicinity of an opening end of a first liner constituent member and a second liner constituent member made of a resin material, a flange portion is formed. After end surfaces of the opening end are abutted and joined to each other, the flange portion is removed in such a way that a part of a bottom portion remains. The remaining amount of protrusion is set such that the joint strength of a joint portion is not less than the tensile strength of the resin material or not less than the cohesion failure strength of the joint portion.