Deformation of the plastic mold products as well as the reasons of the crack. Residual internal stress in the products, to shape the set conditions should be set to eliminate products of internal stress direction. Increase of material barrel temperature and mould temperature, the material liquidity good state, the injection pressure is not too high. Now let's look at the plastic deformation of die products produced by several reasons:
1. The shape of the products quality, especially forming shrinkage relationship with product thickness caused by residual stress;
2. The residual stress caused by molding conditions;
3. Residual stress generated in demoulding;
4. Due to insufficient cooling time.
In order to reduce the residual stress, annealing processing, namely under thermal deformation temperature of 10 degrees, more than 2 hours of heating has the effect of stress relief. But this way because of the high cost of annealing and use is not common. If the mould cooling hole not to cooling homogeneity of products, also can produce residual stress, which means cooling hole can not too shallow.
1. Sufficient cooling solidification in the mould (chronograph longer cooling time), and improve the temperature of the material, reduce the injection pressure.
2. Make the mould cooling uniformity.
3. Avoid products thickness difference, where products large thickness setting sprue (1-1), caused by a straight line easy to warp, make it big R curve, products reversible bending die, increase the number of ejection rod, increase the draft.
Note: the above information by Jiezheng mold finishing on the Internet, welcome to reprint, indicate the source!