China mould maker

6 common polishing methods for plastic molds

There are two main purposes of polishing the mold:

One is to increase the brightness and aesthetics of the plastic mold, and the other is to make the mold easier to demold

When polishing, the rough oil stone is generally used to rough sand the surface of the machined mold cavity to remove the knife marks of the machine tool, and then the traces of the rough oil stone are polished in a fine oil factory. Use fine sandpaper to polish the polished surface of the fine whetstone, and finally use light paste or abrasive paste to polish the surface of the mold cavity to achieve a mirror-like effect.
There are six common plastic mold polishing methods:

1. Mechanical polishing is a polishing method that relies on cutting and plastic deformation of the material surface to remove the polished convexities to obtain a smooth surface. Generally, oil stone strips, semi-fleece, sandpaper, etc. are used, mainly manual operations, special parts such as rotating bodies, for the surface, auxiliary tools such as turntables can be used, and ultra-precision polishing methods can be purchased for high surface quality requirements.

2. Chemical polishing is to allow the material to dissolve the microscopically protruding part of the surface in a chemical medium preferentially, thereby obtaining a smooth surface. The main advantage of this planting method is that it does not require complicated equipment, can polish complex-shaped workpieces, and has high efficiency. The core problem of chemical polishing is the preparation of polishing liquid. The surface roughness obtained by chemical polishing is generally a few 10um.

3. Electrolytic polishing is basically the same as chemical polishing, that is, by selectively dissolving tiny protrusions on the surface of the material to make the surface smooth. Compared with chemical polishing, the effect of cathode reaction can be eliminated, and the effect is better.

4. Ultrasonic polishing---Put the workpiece in the abrasive suspension and put it together in the ultrasonic field, relying on the vibration of the ultrasonic to make the abrasive grind and polish on the surface of the workpiece. Ultrasonic machining has a small macroscopic force and will not cause deformation of the workpiece, but it is difficult to make and arrange tooling.

5. Fluid polishing relies on high-speed flowing fluid and abrasive particles carried by it to wash the surface of the workpiece to achieve the purpose of polishing. Commonly used methods are: abrasive jet processing, liquid jet processing, hydrodynamic grinding and so on.

6. Magnetic grinding and polishing use magnetic abrasives to form abrasive brushes under the action of a magnetic field to grind the workpiece. This method has high processing efficiency, good quality, easy control of processing conditions and good working conditions.