Why can't it be ground further?
The basic law of grinding: Harder abrasives cut (grind) softer ones. Therefore, the material of the abrasive and the object being ground determine whether grinding can proceed. For example, using aluminum oxide grit to grind marble results in mere impact without cutting ability. Conversely, silicon carbide grit makes the grinding much easier. Another factor is the particle size (grit size): coarser grit can cut objects more easily (in less time), while finer grit has poorer cutting ability and takes longer.
Why can't it be polished to a shine?
The aspect of shine refers to the polishing issue. Polishing can be categorized into mirror polishing, glossy polishing, hairline polishing, satin polishing, etc., which are more complex polishing methods. Apart from the material of the object being polished, another crucial factor is the final finishing process. For example, whether it requires electroplating, anodizing, sandblasting, or simpler methods like baking or painting. The choice of final finishing determines the polishing method. As for reasons why it may not shine, it could be due to insufficient cleaning of the entire surface during rough grinding, improper selection of grit size during the process, or incorrect choice of polishing compounds and wheels. Following the correct steps with suitable materials should prevent issues with achieving a shiny finish. There are countless types of grinding materials and endless knowledge to explore. I hope experienced individuals and newcomers alike can share similar grinding experiences generously. Let's learn from each other and grow together. Your knowledge sharing will enhance our proficiency in grinding, improve efficiency, minimize costs, and simplify ways to fulfill customer requirements effectively.
What is meant by grinding materials?
Grinding materials, also known as polishing materials, refer to a collective term for polishing compounds, polishing sands, abrasives, grinding tools, and polishing tools. Grinding materials belong to the category of "hardware tools". The abrasive materials in grinding materials typically include grinding wheels, sandpaper, sand cloth, wire wheels, grindstones, oilstones, grinding heads, grinding discs, cutting discs, sand belts, grinding blocks, flap wheels, flap discs, sponge wheels, cloth wheels, hemp wheels, and other grinding tools.The abrasives in grinding materials include grinding pastes, polishing pastes, polishing waxes, polishing soaps, polishing oils, polishing liquids, emery, polishing sands, black corundum abrasives, brown corundum abrasives, white corundum abrasives, chromium corundum abrasives, zirconium corundum abrasives, as well as natural and synthetic abrasives used for material polishing. These can be used for polishing glass, metal, leather, semiconductor materials, plastics, gemstones, jade, and stainless steel. For example, in glass polishing, iron oxide red, stannic oxide, alumina, cerium oxide, barium carbonate, kaolin, clay, diatomaceous earth, and other powdered mixtures are used in combination with water to form suspensions for use. For metal and plastic polishing, solid polishing pastes are used.
How to choose the specifications of grinding and polishing materials?
Because each type of material for grinding, categorized by shape and size, can encompass as many as thirty to forty varieties,For example, brown corundum (white corundum) grinding stones come in four shapes: round, triangular, oblique triangular, and oblique cylindrical,Among them, the commonly used round shape has twelve different sizes. Based on production practices, the selection of grinding materials for most product parts can follow several principles:
1. The size of the grinding material should generally not exceed the size of the part. It is advisable for the size of the grinding material to be no larger than the size of the part to avoid situations where the grinding material may crush or damage the part.
2.Avoid blocking internal holes or diameters on parts. Some parts have holes or internal diameters on the surface. When choosing grinding materials, special attention should be paid to this situation to prevent the grinding material from blocking a large number of internal holes or diameters during grinding. For such parts, the size of the grinding material selected should be larger than or smaller than the internal hole (diameter).
