As a leading manufacturer of modified plastic granules, TOPONEW recently encountered a challenge when our client was conducting trial molding for automotive interior parts. Surface defects in the form of injection molding part surface dragging occurred. In response, we dispatched injection molding engineers to collaborate with the mold factory's personnel to address the issue promptly. 

Concept of Drag Marks in Injection Molding:

Drag marks, also known as part dragging or surface dragging, refer to the phenomenon where friction between the molded part and the mold during demolding leaves visible traces on the part's surface along the ejection direction.

Impact on Products:

The presence of drag marks significantly affects the appearance of the injection-molded parts, compromising their aesthetics and potentially impairing their assembly.

Root Cause Analysis:

Structural Factors:
Insufficient draft angles or undercuts in the product design.

Mold Factors:
Mold deformation, inadequate polishing, or incorrect mold alignment leading to pre-mold sticking.

Injection Molding Process:
High injection pressure, improper mold temperature, poor venting, excessive use of mold release agents, among others.

Proposed Solutions: 

Structural Adjustments:
Increase draft angles or eliminate undercuts in the product design.

Mold Design Considerations:
Select mold materials with appropriate strength, reinforce polishing

Injection Molding Process Optimization:
Reduce injection pressure, fine-tune mold temperatures, improve venting, and reduce the quantity of mold release agents.

(To address the drag marks issue, we recommend adding a small amount of external lubricant to reduce friction, and increasing the temperature to 60 degrees Celsius.）

By systematically identifying and addressing each potential cause, we can effectively mitigate the occurrence of drag marks in injection-molded products, ensuring high-quality surface finishes and optimal assembly performance.

In conclusion, collaborative efforts between material suppliers, injection molding engineers, and mold manufacturers are vital in resolving surface defects like drag marks, ensuring the production of flawless plastic components for various applications. At TOPONEW, we remain committed to delivering innovative solutions and technical expertise to overcome challenges and drive excellence in the plastics industry.