Direct Factory Plastic Injection Mold with POM Polished Finish for Bevel Gear

Injection Molding Process for Plastic Gears

1. Material Preparation

• Select engineering plastics (e.g., POM, PA66, PBT) that meet the gear’s strength and wear-resistance requirements.

• Dry the material (remove moisture) to prevent bubbles in the finished gear.

2. Mold Preparation

• Use a high-precision gear mold (tooth profile machined via CNC for strict tolerance control).

• Clean the mold cavity and apply mold release agent (for easy part ejection).

3. Core Injection Molding Steps

1. Plasticization

   Heat the plastic pellets in the injection machine’s barrel to melt them into a uniform melt (temperature varies by material: e.g., 180–220°C for POM).
2. Injection

   The machine’s screw injects the melt into the gear mold cavity at a pressure of 50–150MPa, filling all tooth details completely.
3. Packing & Holding

   Maintain pressure for a short time to compensate for shrinkage during cooling, ensuring dimensional accuracy of the gear.
4. Cooling

   Cool the melt via the mold’s cooling channels until it solidifies (10–30 seconds, depending on gear thickness).
5. Ejection

   Open the mold, and use ejector pins to remove the finished plastic gear.

4. Post-Processing (As Needed)

• Trim gates and flash; high-precision gears may undergo annealing (to eliminate internal stress and prevent deformation).

Key Notes

• Mold precision directly determines gear tooth accuracy (strict control of tooth pitch and profile tolerances is required).

• Adjust injection parameters (temperature, pressure, holding time) to match the plastic material, avoiding defects like shrinkage, flash, or short shots.