会社のニュース Seven Common PC/ABS Injection Molding Defects and Their Solutions

Processing PC/ABS blends can present specific challenges. Here is a consolidated guide to the seven most frequent problems and their targeted solutions to ensure high-quality production.

Silver Streaks: Manifesting as silver-white streaks, this is caused by gas interference—entrapped air, material moisture, or pyrolysis gas. The primary solution is to verify material dryness and then fine-tune the injection molding process. Ensuring proper mold exhaust is also critical.

Flow Marks: These surface blemishes occur due to poor material fluidity during injection. To resolve this, increase the material temperature to improve flow. Alternatively, adjusting the mold temperature and reducing the injection speed can be effective.

Shrinkage and Voids: Shrinkage holes form from inadequate cavity filling. Counter this by increasing mold and material temperatures, extending holding time, and raising injection pressure and speed. Voids or dents are often a temperature-related issue; an incorrect melt temperature or a product design that promotes uneven cooling can be the culprit. Optimizing processing parameters and increasing injection speed are key measures.

Warpage and Deformation: Caused by internal stress and uneven shrinkage, this can be addressed through processing adjustments like lengthening the cycle, reducing injection temperature, and optimizing ejection. In part design, increasing wall thickness and adding ribs help improve structural rigidity.

Jetting: This defect is caused by "melt rupture" from high-speed injection. Remedies include raising the material and nozzle temperature, slowing the injection speed, increasing the mold temperature, and modifying the gate design to facilitate smoother material entry.

Pitting: Surface pits can stem from poor additive dispersion or mold issues. Solutions involve improving dispersion with additives or higher temperature, checking the mold condition, and confirming that the raw material has been dried sufficiently.

Delamination: Peeling is linked to high shear forces causing flow instability. To combat this, ensure material compatibility with appropriate additives. In mold design, minimize shear by avoiding small gates. In the process, increase melt and mold temperatures to reduce flow resistance and the need for high shear during filling.