Polishing methods for injection molds

Polishing injection molds is a process of fine machining the surface of the mold, aimed at reducing the roughness of the mold surface to obtain a smooth surface. This helps improve the appearance quality of plastic products, reduce demolding resistance, and extend the life of the mold. Here are some of the main polishing methods:

Mechanical polishing: Use rotating polishing wheels, sandpaper, abrasive belts, and other mechanical tools for polishing. This is a common polishing method suitable for removing welded joints, cutting marks, or other large defects.

Chemical polishing: corroding the surface of the mold with chemical agents to reduce surface roughness. Chemical polishing is favored for its ability to process complex shapes without the need for complex equipment.

Electrolytic polishing: Smooth the surface of the mold by performing electrolytic action in a specific electrolyte. The electrolysis process forms a thin film on the surface of the mold, and when current passes through, the micro high points on the surface are preferentially dissolved, thereby leveling the surface.

Ultrasonic polishing: Suspend abrasive in a solvent and use ultrasonic vibration to grind and polish the surface of the mold. This method is suitable for complex and fine structures that are difficult to polish using conventional methods.

Fluid polishing: using high-speed flowing liquid and abrasive particles to impact and grind the surface of the mold to reduce surface roughness.

Magnetic polishing: Polishing molds using abrasive particles in a magnetic field. This is an effective polishing method for areas with complex shapes and difficult to access.

Hand polishing: relying on the experience and skills of skilled workers, using hand tools such as sandpaper, wire brushes, polishing paste, etc. for fine polishing, this process often requires high skills and patience.

Before polishing, the appropriate polishing method should be selected based on the desired surface roughness, mold material, and final product requirements. Typically, achieving high mirror finish may require multiple polishing steps, from rough polishing to fine polishing, until the desired surface finish is achieved. Caution should be exercised during the polishing process to avoid accidental damage to the mold.