Weld Line in MIM Smartphone Lens Ring

MIM process manufacture notes that weld line is a common defect in MIM process. Looking at the reason for weld line based on our last experience of UAV remote control metal button project.

Weld line refers to the junction lines left in wave front when material flow into mould.

 
The causes and treatment:
- the temperature of mould or material is too low

- pressure is too low or insufficient shooting speed

- illiquidity material
- improper design for product thickness

- mould flow channel or injection gate is too small
- bad exhaust channel

- spray too much mold release agent