A review of research progress on the minimization of weld lines in injection molding

Injection molding is in high demand in several industries due to its efficiency and versatility. Quality control plays a crucial role in ensuring the excellence of plastic products during injection molding. However, the phenomenon of weld lines has persisted due to the susceptibility of melt flow in the mold cavity for independent or multiple related parameters. This paper presents a comprehensive review of recent advances in minimizing weld lines during injection molding. This review study is categorized into four parts, namely, (1) causes of formation, (2) influencing factors and mechanisms, (3) numerical prediction methods, and (4) improvement methods for weld lines. In the end, based on the findings summarized in this review paper, future research directions for optimal control of weld lines are discussed.