How to Overcome Surface Finish Imperfections in Plastic Injection Molding?

Injection Molding

Injection Molding

Flawless surface finishes are crucial in the field of plastic injection molding. Even so, the path to perfection is not always simple. Surface finish flaws such as blisters or bubbles, scratches, or burns can negatively affect the appearance and efficiency of molded products. In this blog, we go over techniques and approaches for overcoming problems and achieving high-quality surface finishes in plastic injection molding.

Knowledge of Surface Finish Flaws:

• Blisters or bubbles in molded parts are caused by retained areas of air or gas due to insufficient venting or the release of volatile substances from the plastic. They appear as prominent bumps or holes on the part’s surface, potentially affecting both its visual appeal and structural strength.

• Surface scratches are minor marks or scrapes on the surface of the item, typically resulting from rough wearing in the mold cavity, incorrect ejection, or mold surface contamination. Scratches can diminish the overall look of an item and possibly require additional finishing processes after molding to eliminate them.

• Burn marks are pigmentations or dark spots on the part’s surface that are usually caused by the plastic getting too hot or breaking down during the process of molding. They can occur due to high injection or mold temperatures, extended residence time, or insufficient cooling.

Methods to address surface finish flaws:

• Enhance Mold Design: The mold design significantly impacts the attainment of excellent surface finishes. Use molds with smooth surfaces and premium finishes to minimize roughness on the surface. Achieve consistent filling and lessen flow disruptions by focusing on gate layout, runner arrangement, and parting line placement to prevent surface defects.

• Improve Ventilation and Cooling: Enhance ventilation in the mold design by incorporating vent channels, vent pins, or venting grooves. Create molds with efficient cooling channels to guarantee balanced cooling throughout the part.

• Minimize Resin Degradation: Resin degradation should be kept to a minimum by monitoring and controlling melt temperatures, residence times, and barrel temperatures. This will help to prevent resin degradation and ensure that the quality of the parts remains consistent.

• Examine and maintain tooling: Clean molds completely after each use, inspect for any indications of breakdown or harm, and carry out essential adjustments or maintenance to guarantee peak mold efficiency and part excellence.

In plastic injection molding, producing flawless surface finishes requires technical expertise. Bigmate Philippines Inc. can improve the quality of your molded parts by using optimal production parameters, advanced mold design, modern equipment, and post-molding finishing methods to address surface finish imperfections. Bigmate Philippines Inc. is dedicated to pursuing excellence in plastic injection molding by focusing on providing flawless surfaces.

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