In the process of injection molding, we often encounter problems such as bulge, burst, low tensile torque, etc. for problems such as not in place after embedding, surface scalding and glue overflow, we can adjust the parameters to solve them; The bulge, burst and low tensile torque of the column position can not be improved by parameter adjustment, or can not be completely solved. The final solution should be improved by optimizing structural design.

Optimize structural design

1. Bulge and burst of column position

This phenomenon can be solved from the following points:

A. Increase the diameter of the column;

B. Reduce the outer diameter and length of the nut to an appropriate value;

C. Increase the outer diameter of the column;

D. Deepen the weld lines outside the nut.

Optimizing structural design 2

2. Low tensile torque

For this phenomenon, we can start from:

A. Deepen weld lines;

B. Change the direction of weld lines;

C. Increase and deepen the tensile groove;

Requirements for plastic column position hole

Generally, the inner diameter of the plastic is about 0.25mm-0.3mm smaller than the maximum outer diameter of the nut. The depth from the bottom of the plastic hole to the lower end face of the nut should be more than 0.5mm for rubber storage;

The wall thickness of the nut plastic column position hole above m1.4 specification shall be more than 1.0mm;

The plastic column position hole should be a conical hole with a large top and a small bottom. Therefore, the draft angle should be 0.5 ~ 2 °;

The diameter value of the plastic aperture is the lower limit value after molding. When opening the pin on the mold, please record the shrinkage value of the plastic material to calculate the pin diameter value, so as to avoid that after molding,

The diameter of the plastic hole is less than the lower limit, resulting in glue overflow after the nut is embedded.