Sand belt production process for sand belt substrate, abrasive, binder and sand density requirements are extremely strict, the premature end of sand belt life, often due to improper use and caused by the following several typical problems for analysis.

1. Glue cover:

When a layer of metal material is covered on the cutting edge of the abrasive grain, the adhesive cover will occur. At this time, the surface of the abrasive belt will become shiny, and the hand will feel slippery. Adhesive caps mainly occur in high strength metal materials, especially hard and tough materials are more serious.

The lack of grinding pressure is the main cause of adhesive cap. For the material with high hardness, the lack of pressure makes it difficult for the abrasive particles to cut into the workpiece and to break and sharpen themselves.

Soft contact wheel or platen, even with high enough grinding pressure, that will only make it collapse seriously, grinding grains difficult to press into the workpiece.

The higher belt speed makes the abrasive particles in the grinding area short of time, the cutting depth of the workpiece becomes thinner, and the heating is serious.

The cause of adhesive cap is comprehensive, its solution is also comprehensive, that is, appropriate contact wheel or platen, high enough grinding pressure, low sand belt speed is the fundamental solution to the problem. Of course, it is necessary to choose a good abrasive of self-sharpening.

2. Dull:

In the grinding process, although the abrasive particles still exist, but the sharpness has been very poor. This is because the abrasive cutting edge becomes blunt due to wear. This phenomenon is called blunt. Normal blunt is the end of the life of the sand belt, obviously we refer to here “blunt” is in the abrasive grain has not been used up, mainly is the sand belt choice or improper use caused by the situation.

The softer contact wheel or press plate makes it difficult for the abrasive particles to cut into the workpiece, thus making the blade flat.

The lack of grinding pressure is also easy to blunt abrasive belt, and abrasive is difficult to self-sharpening.

When the workpiece is hard, the choice of sand belt is not appropriate, or sand belt speed is higher, it is difficult to cut into the workpiece and blunt.

The abnormal wear of sand belt seriously affects the service life of sand belt and greatly increases the processing cost.

3. Block:

Plugging is when the abrasive cutting edge is not completely blunt before the abrasive clearance is quickly covered and filled with chip, so that the abrasive belt loses its cutting ability. There are many reasons for the blockage, most of which are caused by improper use, processing materials and selection of sand belts.

The contact wheel or pressing plate is too soft, which makes it difficult for the abrasive particles to enter the workpiece. The abrasive belt is mainly in the grinding state, and the temperature of the processing zone is heated due to friction, which makes the chips “weld” to the abrasive belt and causes blockage. The solution should be the use of hard contact wheel and platen, or peak tooth back contact wheel and platen, can also use small diameter contact wheel and so on.

The abrasive belt speed is too high to make the abrasive particles effectively cut into the workpiece, which will also appear blockage and burn the workpiece, at this time should reduce the abrasive belt speed.

If the processed material is too soft (such as aluminum, copper and other non-ferrous metals), it is easy to cause sand belt surface blockage. Coarse – grained sand belt is adopted under the condition of satisfying roughness requirement. The abrasive belt of silicon carbide with great brittleness is adopted. Use grinding additives, such as the use of lubricants and so on.

The processing surface of the material easy to jam is smooth, for this kind of material can’t use grease and coarse particle sand belt easy to cause scratches, should use super coating sand belt, the product has good chip removal and anti-clogging performance.

4. Control of belt deviation:

Deviation is the key to affect the quality and service life of the sand belt. Unreasonable belt tensioning and adjusting mechanism will cause serious deviation and run-out of the sand belt, which will make the processing quality fail to meet the specified process requirements and greatly shorten the normal service life of the sand belt. The sand belt will be broken and scrapped in a very short time. Therefore, the key to obtain good machining effect and prolong the service life of sand belt is to choose the efficient and reasonable model of support frame casting, transmission and adjusting mechanism.

5. Fracture reason of sand belt joint:

1. Insufficient glue application; 2. Short pressure time and insufficient temperature; 3. High tension and straight wrinkles; 4. Poor stability of transmission mechanism and unreasonable design.

6. Common problems and solutions in the use of sand belts.

Sand belt operation crepe, tear, run off

Check whether the girth of the sand belt is suitable (the range of girth tolerance is generally plus or minus 5mm);

Check whether the cylindricity of the sand belt (difference of circumference at both ends) is too large (generally, the difference of circumference at both ends is less than 5mm);

Check the sand belt for distortion. A simple way to check: lay the strip flat on a flat surface, align the ends of the strip, and see if the other end is distorted;

Check whether there is any foreign matter on the transmission wheel, the grinding plate pad and the workpiece to be machined, whether the contact wheel is parallel, whether the driving spindle is deformed or whether the transmission wheel is seriously worn.

Check whether the cutting quantity of the workpiece meets the requirement.