六. Cracking when the product is ejected

The cracking of the product during ejection is usually due to the fact that the force of the product wrapping the mold is too large, the force is uneven when the product is ejected, and the cracking is caused by the concentration of residual stress.

During process commissioning, the mold temperature is too low, and overfilling will cause the product to crack when ejected.

When designing the mold, it should be noted that the thimble is arranged in the position of ribs, holes, grooves, bosses and other positions with large holding force, the number of thimbles is reasonable, the diameter of the thimble is maximized, the straight jack block is used instead of the square thimble as much as possible, and attention is paid to the place where the holding force is large to do a good job of drafting.

七. Cracking during mold opening

The main reason for the cracking of the product when opening the mold is because of the large amount of glue feeding, the plastic will fill the mold, and the friction with the mold core is too large, and the easiest way to reduce the amount of glue feed and the pressure holding time is the simplest way.

There is also a method to increase the temperature of the moving mold, reduce the temperature of the moving mold, expand and contract, and reduce the friction of the fixed mold, so that the friction of the moving mold increases, and it is also a way to solve the problem of the product sticking to the front mold.

There are other sticky front molds are basically caused by poor design of the front mold of the mold, or the mold is damaged, such as the fixed mold structure is complex and the moving mold has no structure, the front mold has a core-pulling structure and does not pull the core according to the design requirements when the mold is opened, the fixed mold has the top block of the front mold can not be ejected normally when the mold is opened, the rib position draft angle of the front mold is not enough, and the arc transition of the front mold is too sharp, etc., and the problem of cracking of the front mold can only be solved by improving the mold.