1. The material selection of the main working parts of plastic molds is improper. Poor material performance and lack of wear resistance; The mold steel has not been refined and has a large number of smelting defects; The forging process for convex and concave molds and forging blanks is not perfect, and there are residual heat treatment hazards.
2. Plastic mold structure design issues, unreasonable punching die structure. The slender convex mold is not designed with reinforcement devices, resulting in blockages at the discharge port, and excessive unloading force exacerbates the convex mold's ability to withstand alternating loads.
3. The plastic mold making process is not perfect, mainly manifested in poor internal quality of convex and concave forging blanks, problems with heat treatment technology and process, resulting in incomplete quenching of convex and concave molds, soft spots, and uneven hardness.
4. Sometimes micro cracks, even cracks, inadequate grinding and polishing, and excessive surface roughness may occur.
5. Plastic molds are not lubricated or have lubrication but have poor effectiveness.