A method for welding at least two parts including a thermoplastic material and having respective surfaces to be welded, including: inserting an insert between the surfaces to be welded of the two parts; generating heat via the insert; wherein the insert moves in relation to the parts to be welded in a welding direction. Also, an installation adapted for implementation of this method.

A method of producing a polyethylene resin expanded molded product includes filling a mold with expanded polyethylene resin particles, wherein an internal pressure of 0.12 to 0.16 MPa is applied to the expanded polyethylene resin particles in the mold, and forming the polyethylene resin expanded molded product by heating the expanded polyethylene resin particles and fusing the expanded polyethylene resin particles. The expanded polyethylene resin particles includes 100 parts by weight of a polyethylene resin, 0.08 to 0.25 parts by weight of a cell nucleating agent, 0.3 to 0.8 parts by weight of a polyhydric alcohol fatty acid ester, and 0.01 to 10 parts by weight of a hydrophilic compound, each of the expanded polyethylene resin particles having a weight of 2.5 to 3.5 mg. The polyethylene resin expanded molded product has a density of 0.017 to 0.021 g/cm.sup.3 and a thickness of 10 to 40 mm.

A method of coating a field joint, pipe sections for forming a coated field joint, and a coated field joint formed thereby. First and second angular cut backs are provided in the parent coating of each pipe section. The first angular cut back is at an angle of about 30°+−0.5° relative to the longitudinal axis of the field joint, and the second angular cut back is positioned further from the field joint than the first angular cut back. The first and second angular cut backs result in the parent coating having a stepped profile, a step in the stepped profile between the first and second angular cut backs, the step is substantially parallel to the longitudinal axis of the field joint and is often substantially free of indentations. The field joint coating may be injection moulded to have an upstand that is less than or equal to about 5 mm.

The invention relates to a process for producing a ballistic-resistant curved molded article said process comprising forming a stack of a plurality of composite sheets, pressing the stack comprising the composite sheets at a temperature of between 80° C. to 150° C. and a pressure of between 10 and 400 bar for at least 5 minutes to obtain a curved molded article, cooling the compacted stack to a temperature below 80° C. while maintaining the pressure above 10 bar, releasing the pressure from the cooled curved molded article; wherein the composite sheets comprise unidirectionally aligned high tenacity polyethylene fibers and a matrix comprising a polyethylene resin being a homopolymer or copolymer of ethylene having a density of between 870 to 980 kg/m.sup.3 when measured according to ISO1183 and a melt flow index of between 0.5 and 50 g/10 min when measured according to ASTM 1238B-13 at a temperature of 190° C. and a weight of 21.6 kg.

Solid state draw a laminated polymer billet containing two or more polymer compositions laminated to one another to prepare an oriented polymer composition.

The invention provides a flame-retardant biaxially-oriented polyester film which is porous, and has high reflectance. The flame-retardant biaxially-oriented polyester film contains a polymer component containing polyethylene terephthalate and a flame retardant. The polyester film has an intrinsic viscosity of 0.50 to 0.64 dL/g and a density of 1.21 to 1.27 g/cm.sup.3. A content of the polyethylene terephthalate in the polyester film is 70 to 97% by mass. The flame retardant contains at least one phosphorus-based flame retardant selected from the group consisting of a phosphinate and a diphosphinate. A content of the phosphorus-based flame retardant in the polyester film is 3 to 8% by mass. The polyester film is a porous film having an average reflectance of 60 to 74% at a wavelength of 400 to 700 nm. The polyester film has a thickness of 15 to 45 μm.

In a polypropylene-based foamed molded body of the present invention, a density which is measured on the basis of ISO1183 is greater than or equal to 0.15 g/cm.sup.3 and less than or equal to 0.54 g/cm.sup.3, thermal resistance (R) at 30° C. in a thickness direction which is measured on the basis of ASTM E1530 is greater than or equal to 0.020 m.sup.2.Math.K/W and less than or equal to 0.125 m.sup.2.Math.K/W, thermal capacity per unit area (Q) at 30° C. is greater than or equal to 1.0 kJ/m.sup.2.Math.K and less than or equal to 2.5 kJ/m.sup.2.Math.K, and Expression 1 described below is satisfied.

Q>1/(4×R.sup.1/2)  (Expression 1)

A selectively chrome plated object having a substantially flush interface comprises a first portion formed by injection molding a plateable resin and defining a first top surface, a second portion formed by injection molding a non-plateable resin and defining a second top surface, the second portion sitting proud of the first portion such that the second top surface of the second portion is offset from the first top surface of the first portion, and a third portion formed by a chrome plating process where a chrome plating is applied to the first top surface of the first portion such that a third top surface of the third portion is substantially flush with the second top surface of the second portion.

To provide a biaxially oriented polyester film that has extremely low content of antimony, excellent hygiene, few foreign substances, excellent transparency and heat resistance, and is excellent in printability, workability, and productivity. A biaxially oriented polyester film characterized by a content of antimony in the film of 10 ppm or less, a content of phosphorus in the film of 25 ppm or more and 75 ppm or less, an intrinsic viscosity of the film of 0.51 dl/g or more and 0.70 dl/g or less, and a number of defects with a size of 1 mm or more is 1.0 or less per 1000 square meters of the film.

There is provided a polyolefin resin foam sheet having a plurality of cells which is formed by foaming a polyolefin resin, wherein, in the polyolefin resin foam sheet, the average cell sizes and the maximum cell sizes in the MD direction and the TD direction are each a predetermined value, and a ratio [TD strength at break/MD average cell size] and a ratio [MD strength at break/TD average cell size] are both 80 kPa/μm or more.