With the widespread use of plastic products, such as daily necessities and beverage packaging containers, the appearance of the need to often require the plastic mold cavity surface to achieve the degree of mirror polishing. The production of optical lenses, CD-ROM and other mold surface roughness requirements are extremely high, so the requirements of the polishing is also very high.
Polishing not only increases the appearance of the workpiece, but also to improve the corrosion of the surface of the material, wear resistance, but also can make the mold has other advantages, such as plastic products easy to mold, reduce the production of injection cycle. So polishing in the plastic mold making process is a very important process.
Mechanical polishing is * cutting,Plastic Mold the plastic deformation of the material surface to remove the polished polished surface and get a smooth surface of the polishing method, the general use of oil stone, wool wheel, sandpaper, etc., to manual operation, special parts such as the surface of the rotor can be Use turntable and other auxiliary tools, surface quality
Requires a high method can be used ultra-fine grinding. Ultra-fine grinding is the use of special abrasive, containing abrasive in the polishing liquid, the workpiece in the workpiece surface, for high-speed rotary motion. Using this technology can achieve Ra0.008μm surface roughness, is the highest of a variety of polishing methods. Optical lens molds often use this method.
Chemical polishing is to let the material in the chemical medium in the surface of the micro-protruding part of the concave part of the priority to dissolve, resulting in a smooth surface. The main advantage of this method is the need for complex equipment,Plastic Mold you can polish the shape of the complex parts, you can polish a lot of workpieces, high efficiency. The core problem of chemical polishing is the preparation of the polishing solution. The surface roughness obtained by chemical polishing is generally 10 m.
The basic principle of electrolytic polishing is the same as that of chemical polishing, that is, the surface of the selective dissolution material is slightly convex and the surface is smooth. Compared with the chemical polishing, can eliminate the impact of the cathode reaction, the effect is better.
1. For high hardness, high wear resistance and high toughness requirements of the plastic mold, to use carburizing steel to manufacture, and carburizing, quenching and low temperature tempering as the final heat treatment.
2. The requirements of the carburizing layer,Plastic Mold the general thickness of the carburized layer of 0.8 ~ 1.5mm, when the hard plastic filler when pressing the mold carburizing layer thickness requirements of 1.3 ~ 1.5mm, when the soft plastic carburizing layer Thickness of 0.8 ~ 1.2mm. The carbon content of the carburized layer is preferably from 0.7% to 1.0%. If the use of carbon, nitrogen infiltration, the wear resistance, corrosion resistance, oxidation resistance, anti-sticking even better.
3. Carburizing temperature is generally 900 ~ 920 ℃, complex cavity of small molds take 840 ~ 860 ℃ medium temperature carbonitriding. Carburizing insulation time of 5 ~ 10h, the specific thickness of the layer should be based on the requirements to choose. Carburizing process to the use of grading carburizing process is appropriate, that is, high temperature stage (900 ~ 920 ℃) to quickly penetrate the surface of carbon-based parts; medium temperature stage (820 ~ 840 ℃) to increase the thickness of the carburizing layer,Plastic Mold Carburizing layer to establish a uniform and reasonable carbon concentration gradient distribution, easy to direct quenching.
4. After carburizing quenching process by steel different, carburizing can be used: reheating quenching; grading carburizing directly after quenching (such as alloy carburizing steel); medium temperature carbonitriding directly after quenching (such as industrial Pure iron or low carbon steel cold extrusion molding of small precision molds); carburizing air-cooled quenching