Abstract: Described herein are polyhydric alcohols having more than two hydroxyl groups in polyamide compositions including at least one polyamide to increase the weld seam strength after thermal aging of shaped articles produced from the polyamide composition by injection molding. During the injection molding, at least two flow fronts of the polyamide composition collide and form at least one weld seam.

Abstract: Disclosed is a polyamide composition including 30% to 99.9% by weight of a polyamide mixture as component A). Component A) includes aliphatic polyamide A1) and aliphatic copolyamide or terpolyamide A2). The weight ratio of A1) to A2) is 55:45 to 95:5. The polyamide composition also includes 0% to 60% by weight of glass fibers as component B), 0% to 2% by weight of nigrosin as component C), 0.1% to 10% by weight of at least one polyhydric alcohol including more than two hydroxyl groups and a number-average molecular weight (Mn) of less than 2000 as component D), 0% to 20% by weight of further additives as component E). The reported amounts sum to 100% by weight based on the total composition.

Abstract: Described herein is a process for producing a molded body which encloses a cavity, by welding two partial bodies. Also described herein is a die with which the process of producing the molded body can be carried out. Also described herein is a molded body which can be obtained by the process.

Abstract: A process for welding a first molding to a second molding. The process uses an implement including first and second external surfaces. Each external surface further includes a duct. An end of the first molding is heated by a hot gas while the end is at a distance from the duct-entry plane in the range from 3 mm outside the duct to 10 mm inside the duct. A junction area of the second molding is heated by a hot gas while the junction area is at a distance from the duct-entry plane in a range from 3 mm outside the duct to 10 mm inside the duct. The heated end and the heated junction area are then brought into contact with one another and cooled, forming a weld between the first molding and the second molding. Also disclosed is a welded molding obtainable by the process of the invention.

Abstract: Disclosed is a polyamide composition including 30% to 99.9% by weight of a polyamide mixture as component A). Component A) includes aliphatic polyamide A1) and aliphatic copolyamide or terpolyamide A2). The weight ratio of A1) to A2) is 55:45 to 95:5. The polyamide composition also includes 0% to 60% by weight of glass fibers as component B), 0% to 2% by weight of nigrosin as component C), 0.1% to 10% by weight of at least one polyhydric alcohol including more than two hydroxyl groups and a number-average molecular weight (Mn) of less than 2000 as component D), 0% to 20% by weight of further additives as component E). The reported amounts sum to 100% by weight based on the total composition.

Abstract: The use of polyhydric alcohols having more than two hydroxyl groups in polyamide compositions comprising at least one polyamide to increase the weld seam strength after thermal aging of shaped articles produced from the polyamide composition by injection molding, wherein during injection molding at least two flow fronts of the molten polyamide composition collide and form at least one weld seam.

Abstract: A process for welding a first molding to a second molding. The process uses an implement including first and second external surfaces. Each external surface further includes a duct. An end of the first molding is heated by a hot gas while the end is at a distance from the duct-entry plane in the range from 3 mm outside the duct to 10 mm inside the duct. A junction area of the second molding is heated by a hot gas while the junction area is at a distance from the duct-entry plane in a range from 3 mm outside the duct to 10 mm inside the duct. The heated end and the heated junction area are then brought into contact with one another and cooled, forming a weld between the first molding and the second molding. Also disclosed is a welded molding obtainable by the process of the invention.