Reasons That Affect The Service Life Of The Abrasive Belt
The abrasive belt production process has extremely strict requirements on the abrasive belt substrate, abrasives, binders and sand planting density. The premature end of the abrasive belt life is often caused by improper use. Here are a few typical examples.
1. Sticky cover:
When a layer of metal material is covered on the abrasive cutting edge, the sticking occurs, and the surface of the abrasive belt becomes bright and shiny, and the hand feels slippery. The sticking mainly occurs in metal materials with high strength, especially in hard and tough materials.
Insufficient grinding pressure is the main reason for sticking caps. For materials with high hardness, insufficient pressure makes it difficult for abrasive particles to cut into the workpiece and to break and self-sharpen.
A softer contact wheel or pressure plate, even with a high enough grinding pressure, will only make it collapse seriously, and it is difficult for the abrasive particles to be pressed into the workpiece.
The higher abrasive belt speed makes the time of the abrasive grains in the grinding area insufficient, the depth of the cut into the workpiece becomes thinner, and the heat is severe.
The causes of sticking caps are comprehensive, and the solutions are also comprehensive, that is to say, a suitable contact wheel or pressure plate, a sufficiently high grinding pressure, and a low abrasive belt speed are the fundamental solutions to the problem. Of course, it is also necessary to choose abrasives with good self-sharpening.
2. Dull:
During the grinding process, although the abrasive particles still exist, the sharpness is already very poor. This is due to the dulling of the abrasive grain cutting edge due to wear, a phenomenon known as blunting. Normal blunting is the end of the life of the abrasive belt. Obviously, the "blunting" we refer to here is when the abrasive grains have not been used up, mainly caused by the selection or improper use of the abrasive belt.
A softer contact wheel or pressure plate makes it difficult for abrasive particles to cut into the workpiece, resulting in a flat edge.
The lack of grinding pressure is also easy to blunt the abrasive belt, and the abrasive is difficult to self-sharpen.
When the workpiece is hard, the selection of the abrasive belt is not appropriate, or the abrasive belt speed is high, and it is difficult to cut into the workpiece and become dull.
The abnormal wear of the abrasive belt seriously affects the service life of the abrasive belt and greatly increases the processing cost, so it cannot be ignored.
3. Blockage:
Blockage is that the gap between the abrasive grains is quickly covered and filled with chips before the abrasive grain cutting edge is completely blunt, so that the abrasive belt loses its cutting ability. There are many reasons for clogging, mostly due to improper use, material to be processed and selection of abrasive belts:
The contact wheel or pressure plate is too soft, making it difficult for abrasive grains to cut into the workpiece, and the abrasive belt is mainly in the grinding state. The solution should be to use a hard contact wheel and pressure plate, or a contact wheel and pressure plate with a peak tooth back, or a small diameter contact wheel and so on.
If the abrasive belt speed is too high, it is difficult for the abrasive particles to effectively cut into the workpiece, and blockage and workpiece burn will also occur. At this time, the abrasive belt speed should be reduced.
The material to be processed is too soft (such as non-ferrous metals such as aluminum and copper), which can easily cause the surface of the abrasive belt to be blocked. The solution should be: use a thinning abrasive belt; use a coarse-grained abrasive belt under the condition that the roughness requirements are met. Use the brittle silicon carbide abrasive belt; use the method of adding grinding aids, such as the use of lubricants.
The processing surface of easy-to-clog materials is smooth. For such materials, grease and coarse-grained abrasive belts that are easy to cause scratches should not be used. Ultra-coated abrasive belts should be used. This product has good chip removal and anti-clogging performance.
4. Control of belt deviation:
Deviation is the key to affecting the quality and service life of the abrasive belt. The unreasonable design of the belt tensioning and adjustment mechanism will cause serious deviation and jumping of the abrasive belt, so that the processing quality cannot meet the specified process requirements. Shorten the normal service life of the abrasive belt, and the abrasive belt will be broken and scrapped in a very short time. Therefore, choosing a model with high-efficiency and reasonable transmission and adjustment mechanisms is the key to obtaining good processing results and effectively extending the service life of the abrasive belt.
5. Reasons for fracture of abrasive belt joints:
1) The glue is not enough;
2) The pressure time is short and the temperature is not enough;
3) Large tension, straight wrinkle; small tension, oblique wrinkle
4) The stability of the transmission mechanism is poor and the design is unreasonable.
6. Common problems and solutions for the use of abrasive belts:
The abrasive belt is creped, torn, and deviated when the machine is running.
Check whether the perimeter of the abrasive belt is suitable (the tolerance range of the perimeter is generally plus or minus 5mm);
Check whether the cylindricity of the abrasive belt (the difference between the perimeters at both ends) is too different (generally, the difference between the perimeters at both ends is less than 5mm);
Check that the belt is not twisted. Simple inspection method: unfold the abrasive belt on a flat ground, align the ends of the abrasive belt on both sides, and see if the other end is twisted;
Check whether there are foreign objects on the transmission wheel, the pad of the grinding plate and the workpiece to be processed, whether the contact wheel is parallel, whether the transmission spindle is deformed or whether the transmission wheel is seriously worn.
Check whether the cutting amount of the workpiece meets the requirements.
