How to improve the service life of plastic mold surface coating technology?
Electroplating: Electroplating of hard chromium and hard nickel is a traditional technique for the surface treatment of plastic molds in my country. It is a kind of wet plating by depositing a thin layer of metal or alloy on the surface of plastic molds that have been mirror-processed by electrochemical methods. Electroplating is operated in a relatively low temperature environment, which does not affect the function of the mold itself, so the deformation of the mold is small. At the same time, the low friction coefficient of the coating and the microhardness of up to 800HV greatly improve the wear resistance of the plastic mold. However, because of its large pores, low corrosion resistance and sharp-point effect, it cannot handle the grooves and deep holes of the mold. Therefore, the electroplating method is not suitable for some plastic molds that are porous, multi-grooved, disordered, and have strict requirements on corrosion resistance.
Brush plating: Brush plating (brush plating) technology equipment is relatively simple, the process is sensitive, the operation is convenient, the quality of the coating is good, and it is convenient to carry. It is especially suitable for those large molds that may need to be operated in the field, and no matter what scale or shape. Brush plating can be used, as long as the plating pen can be touched properly, the brush plating can be completed. This is of practical value for strengthening and correcting large-scale fine plastic molds. In mold production, brush plating is mainly used for polishing and strengthening plastic molds, eliminating the need for cavity polishing operations of fitter, improving mold finish, hardness, wear resistance and oxidation resistance, and extending mold life. Brush plating is also particularly suitable for the correction of scrapped molds and large molds. It can correct part of the plastic mold cavity surface scratches, shedding, rough grooves, pits, and large area size tolerances caused by processing and wear, and the correction cycle Short, low cost, and significant economic benefits.
Electroless plating: Electroless plating does not need to be electrified. The metal ions in the electrolyte solution are chemically reduced to metal by a reducing agent and deposited on the surface of the workpiece, and can be firmly combined with the outer surface of the substrate to form a plating layer. In electroless plating, there is no problem in electroplating due to uneven power distribution, which results in the formation of deep plating ability and slack ability. It is the most effective treatment for plastic molds with messy shapes, deep grooves, multiple holes, and messy edges and corners, which makes up for the shortcomings and lack of electroplating. For example, using 45# steel and surface Ni-P chemical plating instead of stainless steel to make plastic molds can not only reduce mold manufacturing costs, but also increase mold service life. Because the plating layer improves the demolding function, the plastic forming cycle is shortened, and the appearance quality of the profile Obviously improved. One of the electroless plating, Ni-P electroless plating, has a very low processing temperature, and the original accuracy of the mold will not be affected. Therefore, it also has unique advantages in fine plastic molds that require strict processing accuracy.