What are the common polishing methods for molds?
1: Mechanical polishing of injection mold processing
Mechanical polishing is a polishing method that removes the polished convex portion by plastic deformation on the surface of the raw material to obtain a smooth surface. Usually, oil stone strips, wool wheels, sandpaper, etc. are used, which are mainly operated by hand, and unique parts such as the surface of the rotating body can be used. The use of auxiliary equipment such as turntables, high surface quality requirements can be selected by ultra-fine polishing. Ultra-fine grinding and polishing is a special-purpose grinding tool. In the polishing liquid containing abrasive, it is pressed against the machined surface to perform high-speed rotation. With this technique, it is possible to reach a surface roughness of Ra of 0.008 μm, which is high in various polishing methods. Optical lens molds are often chosen this way.
2: Chemical polishing of injection mold processing
Chemical polishing Chemical polishing is a process in which a portion of a material that is finely convex on a surface of a chemical medium is preferentially dissolved in a concave portion to obtain a smooth surface. The key advantage of this method is that it does not require complicated equipment, and it is possible to polish a complex workpiece. It is also possible to polish many workpieces at the same time with high efficiency. The core issue of chemical polishing is the formulation of the polishing fluid. The surface roughness obtained by chemical polishing is usually several 10 μm.
3: Electropolishing of injection mold processing
Electropolishing The basic principle of electropolishing is the same as chemical polishing, which is to selectively dissolve the surface of the material to make the surface smooth. Compared with chemical polishing, it is possible to eliminate the influence of the cathode reaction and the effect is better.
4: Ultrasonic polishing of injection mold processing
Ultrasonic polishing The workpiece is placed in an abrasive suspension and placed together in an ultrasonic field. The abrasive is ground and polished on the surface of the workpiece by the action of ultrasonic waves. Ultrasonic machining has a small macroscopic force and does not cause deformation of the workpiece, but tooling manufacturing and installation are troublesome. Ultrasonic processing may be combined with chemical or electrochemical methods. In the solution erosion, electrolysis basically, the ultrasonic vibration is applied to stir the solution to get rid of the dissolved products on the surface of the workpiece, and the surface is adjacent to erosion or electrolyte average; the cavitation of the ultrasonic wave in the liquid can also suppress the erosion process, which is beneficial to surface illuminating.