There are two main purposes for polishing precision injection molds, one is to increase the brightness and aesthetics of precision molds. The second is to make the mold easy to demold. When polishing, a coarse oilstone is generally used to roughly polish the surface of the precision injection mold cavity machined by the machine, to remove the knife marks of the machining tools. Then, a fine oilstone is used to polish the rough oilstone to achieve the marks. Then, a fine sandpaper is used to polish the surface of the fine oilstone. Finally, polishing paste or grinding paste is used to perform the final fine polishing and polishing on the surface of the mold cavity, achieving a mirror like effect.

1. Mechanical polishing: Precision injection mold mechanical polishing is a polishing method that uses cutting and plastic deformation of the material surface to remove the polished protrusions and obtain a smooth surface. It generally uses oilstone strips, wool wheels, sandpaper, etc., and is mainly operated manually. Special parts such as the surface of the rotary body can use auxiliary tools such as turntables. For high surface quality requirements, ultra precision polishing can be used. Ultra precision polishing is the use of specially designed grinding tools, which press tightly on the surface of the workpiece in a polishing fluid containing abrasives and perform high-speed rotational motion. By utilizing this technology, Ra0.008 can be achieved μ The surface roughness of m is the highest among various polishing methods. Optical lens molds often use this method.

2. Electrolytic polishing: Precision injection mold electrolytic polishing, which selectively dissolves small protrusions on the surface of the material to make the surface smooth. Compared with chemical polishing, it can eliminate the influence of cathodic reactions and achieve better results. The electrochemical polishing process is divided into two steps: (1) macroscopic leveling, diffusion of dissolved products into the electrolyte, and a decrease in geometric roughness of the material surface Ra>1 μ M. (2) Low light smoothness, anodic polarization, and increased surface brightness Ra<1 μ M.

3. Ultrasonic polishing: Precision injection mold workpieces are placed in abrasive suspension and placed together in an ultrasonic field, relying on the oscillation effect of ultrasonic waves to grind and polish the abrasive on the surface of the workpiece. Ultrasonic machining has low macroscopic force and will not cause deformation of the workpiece, but it is difficult to make and install fixtures. Ultrasonic processing can be combined with chemical or electrochemical methods. On the basis of solution corrosion and electrolysis, ultrasonic vibration is applied to stir the solution, causing the dissolution products on the surface of the workpiece to detach and the corrosion or electrolyte near the surface to be uniform; The cavitation effect of ultrasound in liquids can also suppress the corrosion process and facilitate surface gloss.