This guide outlines critical factors for TPU injection molding, covering material properties, pretreatment, mold design, process parameters, and solutions to common defects.

Return pins are core functional components of the ejection system in injection molds. Their performance affects mold cycling efficiency, product demolding quality, and equipment safety.

Glass fiber-reinforced material injection molding is a process that enhances the mechanical properties (e.g., rigidity, heat resistance, wear resistance) of products by incorporating reinforcing materials like glass fibers into standard injection molding.

A sub gate, also known as a hidden gate, refers to a gate design where the gate is cleverly positioned within the internal structure or inconspicuous areas of the product during mold design. This ensures no visible gate marks on the product surface after molding. This design not only enhances product aesthetics but also optimizes melt flow and cavity filling, meeting the demands of high-quality manufacturing.

The draft angle in injection-molded products refers to the inclined angle between the product

The gate is the passage that connects the runner and the cavity in an injection mold. Its location and form significantly affect the quality of the molded part, production efficiency, and mold life. A reasonable gate layout ensures smooth filling of the cavity with the melt, reduces defects, and improves product quality.

In multi-cavity mold design, runner balance directly impacts filling uniformity across cavities and the consistency of product quality.

The inspection and acceptance of injection mold bases are critical steps before mold assembly and manufacturing, directly impacting mold precision, service life, and production stability. Hidden defects or dimensional deviations in the mold base can lead to issues such as difficult mold clamping, ejection jamming, or even product scrap during mass production.

During the injection molding process, after the molten plastic is injected into the mold cavity under high pressure and solidified, the cooled product must be separated from the mold using an ejection mechanism. The primary goal of ejection mechanism design is to ensure that the product is safely and completely ejected from the mold surface with minimal force and uniform stress distribution once it has fully cooled or achieved sufficient strength.

Weld lines, a common defect in injection molding, occur when multiple streams of molten plastic converge in the mold but fail to merge fully. These lines can compromise a product’s appearance, structural strength, and sealing performance.