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Micro injection mold makers should be aware of injection molding defects

2023-06-09 00:00:00

Injection molding is both an art and a science for micro injection mold makers.  A high level of technical expertise and attention to detail is required to prevent the loss of defects due to injection molding when mass-producing new products.  


Let's talk about the phenomenon and reason of injection malformation.


1. Insufficient filling -- the resin is not completely filled with cavity to make the product defect phenomenon.  

The reasons for insufficient filling are as follows:  

1) The volume of the formed product is too large  

2) The runner and gate are too small  

3) Low nozzle temperature  

4) The material temperature or injection pressure is low  

5) The fluid flow distance in the inner cavity is too long  

6) The speed of injection is too slow  

7) The mold temperature is low  

8) The supply of materials is too small  

9) Poor exhaust  



2. Fly-edge -- the phenomenon of molten resin flowing out of the composite surface of the mold.  

The causes of flying edge are as follows:  

1) Insufficient clamping force  

2) Bad mold  

3) Impurities on the die surface  

4) The material temperature is too high  

5) Material supply is excessive  

6) High injection pressure  



3. Porosity -- when the material is not sufficiently dry, it is caused by volatiles or air;  Most of the time, it occurs at the thickness of the product, which is actually the vacuum bubble caused by the shrinkage of the material.  

1) Poor mold design  

2) Insufficient pressure holding  

3) Moisture or volatile components  

4) The material temperature is too high  



4. Radial pattern -- the phenomenon that the resin injected from the gate to the cavity is solidified in a button-like state and the surface of the product shows a snake pattern.  

1) Poor material flow  

2) The mold temperature is low  

3) The gate is too small  



5. Cracking - is actually caused by the internal stress caused by the molecular structure of the material when it is injection molded from an irregular state into a specific shape.  

1) The injection pressure is too strong  

2) Poor material flow  

3) Poor exhaust  

4) Poor adjustment of pressure holding  

Actually, in the usual mold production process, the micro injection mold makers meet lots of this kind of phenomenon, we are only talking about some of them, as a result, micro injection mold makers should know more about this knowledge, accumulate experience in practice, and make preventive measures, so as to better to avoid injection defects caused by the product quality problems.