Heat treatment of plastic cap injection mold is a very important process. Generally, the plastic cap injection mold will be quenched and tempered before finishing, and then directly processed after being cold-processed, which not only ensures the use performance of the mold, but also avoids deformation of the mold caused by heat treatment. 

    Firstly, we carry out pre-heat treatment, first heat the plastic cap injection mold to 840-860 °c, keep warm for 2 hours; wait for the temperature 710-730 °c, keep warm for 4 hours. Then re-anneal: the furnace is cooled to below 500 °C and then cooled in the air, so that the hardness can reach ≤ 229HBS, and then after high temperature tempering, the plastic cap injection mold is heated to 720-740 ° C, the holding time is also 2 hours. Finally, the annealing furnace is cooled to below 500 ° C and cooled in air. After quenching and tempering, the recommended quenching process: temperature is 850-880 ° C, oil cooling, hardness is 50-52HRC; tempering process: temperature is 580-640 ° C, air cooling, hardness is 28-36HRC.

        After the heat treatment of the plastic mold, the surface roughness of the steel can be reduced to 0.03 μm, the brightness of the surface of the plastic mold can be further improved, and the service life of the mold will be greatly improved.

       Our factory is specializes in product Plastic cap, plastic closure, plastic spout cap, plastic lid, metal can, tin can, stainless steel can, metal jar, flip Top cap, screw cap, pull out cap, Closures Injection Molding Machineetc.