Abstract: This paper introduces the method and working principle of mold polishing, common tools and equipment, process characteristics, operation methods and techniques, and analyzes the factors affecting the polishing effect and the precautions during polishing. Provide a reference for the reasonable selection of polishing methods in mold manufacturing, analysis and resolution of various problems in polishing. In the process of diversification and high-grade development of industrial products, how to improve the quality of molds directly affecting product quality is an important task. In the mold manufacturing process, smooth processing and mirror processing after shape processing are called surface grinding and polishing of parts, which is an important process to improve the quality of the mold. Mastering a reasonable polishing method can improve mold quality and service life, thereby improving product quality. 1 Common polishing methods and working principle 1.1 Mechanical polishing Mechanical polishing is a polishing method that removes the convex surface of the surface of the workpiece by cutting or plastically deforming the surface of the material to obtain a smooth surface. Generally, oil stone strips, wool wheels, sandpaper, etc. are used, mainly by manual operation, and the surface quality is high. The method of super-fine polishing can be used. 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 rotary motion. With this technology, a surface roughness of Ra0.008 μm can be achieved, which is the best surface roughness in various polishing methods. This method is often used in optical lens molds. Mechanical polishing is the main method of mold polishing. 1.2 Chemical polishing Chemical polishing is the process in which the material in the chemical medium allows the surface of the surface to be slightly convex, and the concave portion is preferentially dissolved, thereby obtaining a smooth surface. The method can polish a workpiece with a complicated shape and can polish many workpieces at the same time with high efficiency. The surface roughness obtained by chemical polishing is generally Ra10 μm. 1.3 Electropolishing The basic principle of electropolishing is the same as that of chemical polishing, that is, by selectively dissolving tiny protruding portions on the surface of the material to make the surface smooth. Compared with chemical polishing, it can eliminate the influence of the cathode reaction and has a good effect. 1.4 Ultrasonic polishing Ultrasonic polishing is a processing method that uses a tool section for ultrasonic vibration to polish a brittle hard material through an abrasive suspension. The workpiece is placed in an abrasive suspension and placed together in an ultrasonic field, and 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 it is difficult to manufacture and install the tooling. 1.5 Fluid Polishing Fluid polishing relies on flowing liquid and the abrasive particles it carries to wash the surface of the workpiece for polishing purposes. Hydrodynamic grinding is driven by hydraulics. The medium is mainly made of a special compound (polymeric substance) that flows at a lower pressure and is incorporated into an abrasive. The abrasive can be made of silicon carbide powder. 1.6 Magnetic Abrasive Polishing Magnetic abrasive polishing is the use of magnetic abrasive to form an abrasive brush under the action of a magnetic field to grind the workpiece. This method has high processing efficiency, good quality and easy control of processing conditions. With a suitable abrasive, the surface roughness of the processing can reach Ra 0.1 μm. In order to improve the polishing speed of the workpiece with the surface roughness Ra of 1.6μm or more, the ultrasonic wave is combined with the special high-frequency narrow pulse high peak current pulse power supply for composite polishing, and the ultrasonic vibration and the electric pulse corrosion simultaneously act on the surface of the workpiece, and rapidly reduce The surface roughness, which is effective for polishing the rough surface of the mold after machining by car, milling, electric spark and wire cutting, is very effective. Common tools for mold polishing include: sandpaper, oilstone, felt wheel, abrasive paste, alloy trowel, diamond grinding needle, bamboo, fiber whetstone, round rotary grinding machine. Curtain Decorative Clip &Buckle Decorative Curtain Clips,Golden Triangle Curtain Buckle Holder,Curtain Band and Buckle Taojin Textile Co., Ltd. , http://www.hzcurtain-accessory.com
1.7 Electric spark ultrasonic composite polishing
2 Tools and specifications for mold polishing
Sandpaper: 150#,180#,320#,400#,600#,800#,1 000#,1 200#,1 500#;
Whetstone: 120#,220#,400#,600#;
Felt wheel: cylindrical, rounded, square tip;
Grinding paste: 1# (white) 3# (yellow) 6# (orange) 9# (green) 15# (blue) 25# (brown) 35# (red) 60# (purple);
Sickles: square, round, flat, triangular and other shapes;
Diamond grinding needle: generally 3/32 shank or 1/8 shank, with round shape, cylindrical shape, long straight column shape, long rounded shape;
Bamboo: Various shapes are suitable for the operator and the shape of the mold. The function is to press the sandpaper and grind it on the workpiece to achieve the required surface roughness.
Fiber whetstone: 200# (black) 400# (blue) 600# (white) 800# (red).