2K plastic mold making part: This is a set of 2K plastic molds for the bottom shell of the foot massager. The focus of this set of injection molds is the avoidance of the surface of the hard rubber product mold, and the exhaust of the soft rubber product. If you grasp these two points, there will be no problems with the mold. Similarly, we packed the mold after two trials. Injection molding problem solution 17. Stress Crack

Cause:

The unfavorable phenomenon of cracks in the injection molded part is caused by the excessive shear stress of the plastic in the injection molded part.

When aging occurs, the cracking process begins. The plastic is damaged by shear stress during the plastic molding process.

The process refers to the injection of plastic that is forced to push it into the cavity with greater pressure under the condition of insufficient heating and poor flow.

Plastic behavior, the molecules are excessively elongated, and when aging comes, it is easy to break and cause tortoise cracks, and transparent plastic parts are easier to see

See this phenomenon.

Improve methods:

a) Mould

. Increase the diameter of the runner/interval

. Optimize the wall thickness of molded parts

b) Injection molding machine conditions

. Stage optimization of injection pressure

. Delayed conversion holding pressure

. Reduce holding pressure

. Reduce injection speed

. Increase Wangsu temperature (amorphous material)

. Increase mold temperature (amorphous material)