How To Improve The Wear Resistance Of Trash Can Molds

The working conditions of trash can molds are different from cold stamping molds. Generally, the mold must work between 150 ° C and 200 ° C, in addition to pressure, but also to withstand the influence of temperature. According to the different use conditions and processing methods of the trash can mold, the basic performance requirements of the steel for the trash can mold are roughly summarized as follows:

Excellent machinability: Most plastic forming molds require cutting and fitter repair in addition to EMD machining. In order to prolong the service life of the tool, improve the cutting performance, and reduce the surface roughness, the hardness of the steel used for the trash can must be appropriate.

Good thermal stability: The parts injected into the trash bin mold are often complex in shape and difficult to process after quenching. The thermal stability should be selected as far as possible. After the two-color mold is heat-treated and formed, the linear expansion coefficient is small, the heat treatment deformation is small, the dimensional change rate caused by the temperature difference is small, the metallographic structure and the mold size are stable, and the processing can be reduced or stopped, thereby ensuring the mold dimensional accuracy and surface roughness requirements.

Good polishing performance: high-quality two-color injection molding plastic products require small surface roughness of the cavity. For example, the surface roughness value of the injection mold cavity should be less than Ra 0.1~0.25, and the optical surface should be Ra<0.01nm. Cavities should be polished to reduce surface roughness values. To this end, the selected steel requires fewer impurities, a fine and uniform microstructure, no fiber orientation, and no pitting or orange peel defects during polishing.

Sufficient surface hardness and wear resistance: The hardness of plastic molds is usually below 50-60HRC, and the heat-treated trash can molds should have sufficient surface hardness to ensure sufficient rigidity of the molds. Due to the filling and flow of plastic, the mold has to bear a lot of compressive stress and friction, which requires the mold to maintain the stability of shape accuracy and dimensional accuracy to ensure that the mold has a sufficient service life. The wear resistance of the mold depends on the chemical composition of the steel and the hardness of the heat treatment, so increasing the hardness of the mold is beneficial to enhance its wear resistance.