Beschreibung:
AbstractIn the following article, we will discuss welding of polyamides inside the injection mold. This process is called injection welding. The process of injection welding makes it possible to bond polyamides with quite different characteristics together without adhesive. In this way, one can achieve economic as well as constructional advantages. We will discuss two different methods in this article. In the first process, two melts are injected onto each other simultaneously; with the second technique, the melt is injected onto a thermoplastic insert. The weld line strengths of injection‐welded parts depend on material and process conditions. With an amorphous polyamide, the weld line strength can be attained up to the full tensile strength of the material, while a glass‐fiber‐reinforced polyamide falls back onto the tensile strength of the basic polymer. Injection welding achieves the greatest weld line strength when two melt streams are colliding together with the highest possible injection pressure. If a melt is injected onto an insert, the temperature of the melt should be as high as possible.