Visible defects on TPE injection molded products include dark spots, variations in luster, or haziness areas, as well as surface wrinkles. These defects typically occur near the gate or behind sharp corners away from the gate area. How can we avoid TPE injection molding defects? Below, our staff will share some tips.

How to Avoid TPE Injection Molding Defects?

1. The occurrence of concave holes in molded products is primarily caused by shrinkage during the cooling process within the mold. In addition to the requirement that the material must completely fill the mold cavity, rapid cooling is also crucial. Specifically, this involves increasing the holding pressure (secondary pressure) and lowering the set temperatures of the resin and mold. Moreover, the shape of the molded product is highly dependent on the mold design. Since air pockets are prone to form in thicker areas, such products should be designed with injection ports or channels around them.

2. To prevent residual stress during injection molding, shearing stress, uneven wall thickness of the product, and uneven shrinkage causing internal stress, and to avoid poor ejection, insufficient cooling, and insufficient product strength, which may lead to mold deformation and shape distortion, warping, uneven surfaces, misalignment of the mold cavity, and uneven wall thickness. Additionally, it is essential to avoid issues such as poor mold strength and precision, unstable operation of the injection molding machine, and unstable process and technical conditions, which can cause inconsistent dimensional changes in the product.

3. Choose the appropriate release agents and lubricants, and apply them in the right amount to prevent the appearance of silver threads on the product surface due to improper use.

4. Reduce the injection pressure appropriately, increase the runner and gate sizes, to avoid excessive injection pressure and overly small runners and gates, which may cause silver fibers due to excessive shearing force during material flow.

Here's the summary provided by our staff, hoping it's helpful to you. Should you need further details, feel free to specify.