What does the reason of the product craze in injection molding process have?

What does the reason of the product craze in injection molding process have?

processing

(1) too much processing pressure, too fast speed, more filling, injection, pressure holding time is too long, will cause too much internal stress and cracking.

(2) Adjust mold opening speed and pressure to prevent demoulding cracking caused by rapid and strong drawing parts.

(3) appropriately raise the mold temperature, so that the parts are easy to demoulding, appropriately reduce the material temperature to prevent decomposition.

(4) to prevent cracking due to welding marks and plastic degradation caused by low mechanical strength.

(5) the appropriate use of release agent, pay attention to often eliminate the mold surface attached to the aerosol and other substances.

(6) the residual stress of the parts can be eliminated by annealing immediately after forming to reduce the generation of cracks.

mold

(1) the ejection should be balanced, such as the number of ejection rods and cross-sectional area should be enough, the demoulding slope should be enough, and the cavity surface should be smooth enough, so as to prevent the cracking caused by the concentration of residual stress in ejection caused by external forces.

(2) the structure of the parts can not be too thin, the transition part should be used as far as possible arc transition, to avoid sharp corners, chamfering caused by stress concentration.

(3) minimize the use of metal inserts to prevent the increase of internal stress caused by the different shrinkage rates of inserts and parts.

(4) Deep bottom parts should be set up with appropriate demoulding intake channels to prevent the formation of vacuum negative pressure.

(5) the main channel is enough to release the sprue material before it is cured, so it is easy to release the mold.

(6) the engagement of the main channel bushing and the nozzle should prevent the drag of the cold and hard material and make the parts stick to the fixed die.

material

(1) the recycled material content is too high, resulting in too low strength of the parts.

(2) the humidity is too large, resulting in a chemical reaction between some plastics and water vapor, reducing the strength and the emergence of ejection cracking.

(3) the material itself is not suitable for the processing environment or poor quality, pollution will cause cracking.

Different injection moulds have different requirements. In summary, the performance requirements of plastic moulds for die steel are mainly reflected in: hardness, polishing, etching performance, welding performance, wear resistance, toughness, dimensional stability, corrosion resistance and so on.

Injection Molding Information