Basic knowledge of coated abrasive grinding
1. Grinding points and applicable range of coated abrasives
Coated abrasives are a flexible abrasive article made of abrasive, substrate and adhesive. Grinding of coated abrasives with elastic, high-efficiency cold-cut grinding points, widely used in:
(1) Large flat thick and thin plates, including the processing of metal strips;
(2) Processing of various metal and non-metal workpieces produced in large quantities;
(3) Forming grinding and polishing of complex profile workpieces;
(4) Cylindrical grinding, curved surface grinding, internal grinding, etc. of metal pipes, rods and rolls of various diameters.
(5) The polishing of the polishing wheel can be replaced by a page wheel or a cylindrical sand cover;
(6) Disc-shaped products are used for grinding, deburring, large-area derusting of large shells, boxes, hulls, bridges, etc., which are efficient, convenient and safe.
2. Grinding mechanism of abrasive belt
A coated abrasive can be understood as a multi-blade cutter having a plurality of abrasive grains.
The abrasive particles coated with the abrasive article are uniformly distributed on the surface of the substrate, and are basically a single layer distribution. The special abrasive used for the coated abrasives has a high basic particle content and a uniform particle size, so that the abrasive grains on the surface of the coated abrasive have a good contour arrangement. In particular, the modern coated abrasives are produced by electrostatic sanding, which ensures that the sharp corners of the abrasive grains face outward and the abrasives are oriented. The fixed arrangement and contouring of the abrasive particles on the surface of the coated abrasive are important factors for the high efficiency and cold grinding of the coated abrasive to maintain the grinding.
The typical difference from grinding wheel grinding is that “sand belt grinding is achieved by increasing the vertical load of the belt surface (grinding pressure) rather than by increasing the speed of the belt.
The line speed of the belt is generally in the range of 15-35 m/s, rarely exceeding 50 m/s.
In the grinding process, three different processes occur in the grinding process: sliding rubbing—sliding rubbing of the abrasive grains on the workpiece, resulting in elastic deformation of the workpiece material, and the plough-grinding particles cause plastic flow of the workpiece material, so that The material produces a squeeze motion that is extruded from the underside of the abrasive particles forward and to the sides while cutting a small amount of material; cutting - the material breaks in front of the slip to form chips, with a relatively fast resection rate. The above three processes are interconnected, where cutting is the most effective form of the grinding process.