9 Common mistakes in plastic injection molding and how to fix them

In the plastic injection molding industry, product quality is always a top factor determining the success of a business. However, various issues can arise during the manufacturing process, affecting quality and production efficiency. From cracks and deformations to uneven surfaces and poor durability, these problems reduce product value and can lead to significant additional costs. In this article, Hanoi Mould will analyze the 8 most common mistakes manufacturers encounter in plastic injection molding, along with their causes and effective solutions. Understanding this information will help businesses enhance product quality and improve their competitiveness in the market.

If you are interested in injection molds and need to produce plastic products in bulk, don’t hesitate to contact Hanoi Mould or call our hotline at 0912 308 979 for a consultation!

1. Cracks or breaks in plastic injection molding

Causes:

• Incorrect design: An unsuitable product design can lead to uneven stress, causing cracks or breaks.
• Uneven cooling process: If parts of the product cool unevenly, it may result in deformation.
• Use of Poor-Quality Materials: Substandard materials can reduce the product’s durability.

Solutions:

• Check product design: Use simulation software to evaluate stress in the design, such as Autodesk Fusion 360, ANSYS, or COMSOL Multiphysics.
• Adjust cooling temperature: Establish a uniform cooling process, and consider using cooling equipment to control temperature.
• Select Standard-Compliant Materials: Ensure that incoming materials undergo rigorous quality checks.

2. Flash

Causes:

• Excess material: Excess material escapes from the mold cavity during the injection molding process, resulting in small protrusions or thin fins on the edges of product details.
• Other issues: Problems such as excessively high injection pressure, worn injection molds, incorrect clamping force, or improper mold alignment.

Solutions:

• Adjust injection pressure: Reduce the injection pressure.
• Mold maintenance: Regularly maintain the injection mold and ensure appropriate clamping force and alignment.
• Post-Processing: Trim or sand the product to remove excess material for a more aesthetically pleasing appearance.

3. Uneven surface

Causes:

• Errors in the injection process: This may occur due to incorrect settings of the injection machine.
• Insufficient injection pressure: If the injection pressure is too low, the plastic may not fill the mold.
• Residual solvent: Incomplete evaporation of solvents can affect the product’s surface.

Solutions:

• Adjust injection pressure: Review and adjust injection pressure settings to ensure the plastic fills the mold.
• Check materials: Ensure that the materials are clean and free of impurities before use.

4. Uneven shrinkage

Causes:

• Temperature differences: Uneven cooling temperatures can lead to uneven shrinkage.
• Humidity in the production environment: excessively high or low humidity can also affect the product.

Solutions:

• Control temperature and humidity: Use measurement devices to monitor and adjust temperature and humidity in the production area.
• Ensure uniform cooling process: Utilize fans or cooling systems to maintain consistent temperature.

5. Blisters or air bubbles in plastic injection molding

Causes:

• Trapped air: Air can become trapped during the injection process.
• Too low temperature: If the temperature is too low, the plastic may not flow evenly into the mold.

Solutions:

• Ensure proper heating of materials: Check the temperature of the plastic before injection to ensure it is at an optimal level.
• Control injection pressure: Increase injection pressure to expel air and ensure the plastic fills the mold.

6. Deformed products

Causes:

• Too rapid cooling: If the product cools too quickly, it may cause deformation or warp.
• Incorrect mold design: A poorly designed mold can lead to products that do not retain their original shape.

Solutions:

• Adjust cooling process: Establish a gradual cooling process to avoid sudden shrinkage.
• Control mold temperature: Use temperature control devices to maintain a stable temperature in the mold.

7. Poor durability

Causes:

• Use of Non-Compliant Materials: Poor-quality materials will affect the durability of the product.
• Inaccurate production process: If parameters in the production process are not well-controlled, the products will be affected.

Solutions:

• Inspect and select appropriate materials: Ensure that materials undergo quality checks before production.
• Adhere to strict production processes: Train workers on production processes and implement regular inspections.

8. Inaccurate dimensions

Causes:

• Deviation in mold design: An inaccurate mold can lead to products not meeting the required dimensions.
• Unstable injection process: Changes in the production process can result in dimensional errors.

Solutions:

• Reassess mold design: Conduct inspections and adjustments to the mold design to ensure accuracy.
• Regularly monitor technical parameters: Use monitoring systems such as sensors and measurement devices, dashboards, and production management software to control parameters during production.

9. Scratches or stains on the surface in plastic injection molding

Causes:

• Dirty or poorly maintained molds: If molds are not cleaned regularly, they can cause stains on the product.
• Dirty materials or impurities: Unclean materials can leave scratches on the product.

Solutions:

• Conduct regular maintenance on molds: Schedule regular maintenance to inspect and clean molds.
• Ensure cleanliness during production: Establish a cleaning protocol for materials and molds before production.

Learn more about The plastic injection mold manufacturing process: https://hanoimould.com/prestigious-and-quality-plastic-injection-mold-manufacturing-service-in-vietnam/

If you are interested in injection molds and need to produce plastic products in bulk, don’t hesitate to contact Hanoi Mould or call our hotline at 0912 308 979 for a consultation!

Conclusion

Identifying and promptly correcting issues in plastic injection products is crucial for improving product quality and production efficiency. By implementing the aforementioned corrective measures, businesses can enhance their production processes and better meet market demands. If you need more information or support regarding the injection molding process, please contact us for a detailed consultation!