Causes and solutions for cracks in injection molds

(1) Structural design leads to cracks and their prevention in the design of the mold structure, if the structure is not properly designed, such as the screw hole is too close to the edge, the strength is weakened; the corner is too sharp, there is no smooth transition, causing stress concentration, etc. For various reasons, the mold is cracked due to excessive force during the forming work. For this structural crack, since the mold has been manufactured, it is impossible to change the structure, and it can only be enhanced by adding a frame or the like. .

(2) Improper heat treatment leads to cracks and prevents many parts in the injection mold, such as fixed molds, moving molds, guide columns, guide sleeves, etc., which are indispensable for heat treatment to enhance their wear resistance and prolong their life, but if heat treatment conditions Improper selection, or improper heat treatment, so that the hardness of the parts of the material varies greatly. This difference is easy to produce cracks when the mold is working. For this, the heat treatment conditions should be examined and the heat treatment procedures should be strictly followed.

(3) Insufficient rigidity of the mold leads to cracks and prevents the injection mold from being subjected to strong pressure when working. If the rigidity of the mold is insufficient, cracks may occur under such strong pressure. The key to solving this problem is the mold structure design. The mold must be considered to have sufficient stiffness and strength.

(4) The brittleness of the mold material is too large, causing the crack and preventing some materials from being too brittle. For example, the steel with high carbon content is brittle and the hardness is high when the heat treatment is too high. When the material is subjected to excessive force or impact. Cracks are prone to occur. For this, molds with better toughness should be used.