Difference Between Sandpaper and Abrasive Cloth

Sandpaper and abrasive cloth are common tools in the fields of coating, grinding, grinding, polishing and so on. Their processing objects and application fields are becoming more and more extensive. They can process almost all engineering materials, from general daily life appliances to large Aerospace appliances. Sandpaper and emery cloth are indispensable grinding materials in the polishing and derusting process of paint construction.

1. Sandpaper

Sandpaper, the base material used is paper; Sandpaper is a kind of paper with abrasive particles attached. It is used to level the surface of articles, or remove attachments on the surface of articles (such as old paint). Sometimes it is also used to increase friction. Sand paper is divided into different numbers according to different roughness to match different purposes.

1.1 Different grits of sandpaper

The larger the model of sandpaper, the finer it is, and the smaller it is, the coarser it is. Generally, there are: 30 grit sandpaper (or 30 mesh), 60 grit sandpaper (60 mesh), 120 grit sandpaper, 180 grit sandpaper, 240 grit sandpaper, etc. Number (or mesh) refers to the thickness of abrasive and the quantity of abrasive per square inch. The higher the number, the finer the abrasive and the more quantity. Mesh refers to the number of holes in the screen in an area of 1 in2, that is, the higher the mesh, the more the mesh, and the finer the abrasive.

1.2 Types of sandpaper

Sandpaper is a kind of material for grinding. It is used to grind metal, wood and other surfaces to make them smooth and smooth. It is usually made by gluing various abrasive grains on the base paper. In real life, the categories of sandpaper are mainly divided into sponge sandpaper, dry sandpaper, waterproof sandpaper, etc.

1.2.1 Sponge sandpaper

Sponge sandpaper is mainly suitable for grinding smooth and round parts, and all kinds of materials can be used. The sanding process of sponge sandpaper has the characteristics of high production efficiency, good surface quality and low production cost, especially in the production of furniture industry. The final surface quality of furniture products is closely related to the sanding process, and sponge sandpaper is the main tool of sanding.

1.2.2 Dry sandpaper

Dry sandpaper is made of synthetic resin as binder, then silicon carbide abrasive bonded to latex, and then coated with antistatic coating. This type of sandpaper has the advantages of anti blocking, anti-static, good flexibility and high wear resistance. It has a variety of fineness to choose from. It is suitable for grinding on metal surface, putty and coating.

Dry sand paper is generally made of special kraft paper and latex paper, with natural resin and synthetic resin as binder and advanced high electrostatic sand planting technology. This product has the advantages of high grinding efficiency and not easy to stick chips. It is widely used in furniture, decoration and other industries.

It is used to polish the surface of glass and bamboo (wood) . Moreover, dry sandpaper is not so troublesome, and the gap between sand particles is large, so the debris will be large. In the process of grinding, the debris will fall down due to the large gap, so it does not need to be applied together with water.

1.2.3 Waterproof sandpaper

Waterproof sandpaper, also known as waterproof abrasive paper, is named because it needs to be immersed in water for polishing and polishing. Waterproof sandpaper is an sandpaper tool made of water resistant paper or treated water resistant paper as the matrix, oil or resin as the binder, and silicon carbide or corundum abrasive firmly adhered to the matrix. Its shape has page shape and roll shape.

The polishing sandpaper is delicate and suitable for polishing some delicate things and post-processing. The sand clearance of waterproof sandpaper is small, and the wear debris is also small. When it is used with water, the debris will flow out with the water, so it should be used with water. If it is dry ground with waterproof sandpaper, the debris will stay in the gap between the sand particles, making the surface of the sandpaper smooth, so as to fail to achieve its original effect.

Waterproof sandpaper is used to polish the surface of metal or non-metal workpieces in water or oil. The base paper is made entirely of unbleached kraft wood pulp. The paper is strong and tough, wear-resistant and folding resistant, and has good water resistance. Abrasive materials such as garnet sand are adhered to the base paper with adhesives such as gum and dried.

Its characteristics are: it uses a linkage production line with high efficiency; waterproof sandpaper takes varnish as binder and has a long drying time. Generally, suspension drying method is adopted; The particle size of waterproof sandpaper is generally fine, while the particle size of waterproof sandpaper starts from p80. The particle size of fine sandpaper is related to the particle size of metallographic sandpaper. Waterproof sandpaper is generally polished under the condition of water, which can reduce dust and have superior working conditions.

1.3 Use of sandpaper

Sandpaper polishing is one of the methods of mechanical polishing. Therefore, any polishing process in the use of mechanical polishing pays great attention to some problems in the process, and sandpaper polishing is no exception. What problems should be paid attention to in the application of sandpaper polishing? Please see the following three points:

1.3.1 soft wooden stick and bamboo stick must be used, because when polishing the spherical surface and circular surface, soft wooden stick and bamboo stick can better match the radian of the circular surface and spherical surface. On the contrary, harder wood strips are suitable for polishing flat surfaces. Trimming the end of the wooden rod can keep it consistent with the surface shape of the steel part, so as to avoid deep marks caused by the sharp angle of the wooden strip or bamboo strip contacting the surface of the steel part.

1.3.2 when choosing different types of sandpaper, the polishing direction should be changed appropriately. This can distinguish the effect of stripe shadow left after polishing with different sandpaper before and after polishing. Before changing different types of sandpaper, it is best to carefully wipe the polished surface with 100% cotton dipped in cleaning liquid such as alcohol. Because often a small gravel left on the surface will destroy the whole polishing work. The polishing process pays great attention to the overall cleanliness of the surface, which must be paid attention to when various sandpapers are changed.

1.3.3 in the polishing process, in order to avoid scratching and burning the workpiece surface, be careful when polishing with 1200 grit sandpaper and 1500 grit sandpaper. Anyway, when polishing with each different type of sandpaper, it should be polished in two different directions and angles. To avoid scratches and burns during polishing.

2. Abrasive cloth

Abrasive cloth is a kind of abrasive tools. Sanding cloth, the base material used is cloth. Emery cloth is made by attaching abrasive to the base cloth. As abrasives, there are brown fused alumina, white fused alumina, emery, quartz, light stone, iron oxide, etc. Abrasive cloth can also be divided into different numbers according to the size of abrasive. The abrasive grains on abrasive cloth have stronger cutting ability than those on grinding wheel, so its grinding efficiency is very high.

Abrasive cloth has high grinding efficiency, which is reflected in its high cutting rate, grinding ratio (the ratio of cutting workpiece weight to abrasive wear weight) and machine tool power utilization. Due to the light weight of the abrasive cloth itself, the balance state of its grinding process structure system is easy to control, and the wear of all rotating parts (such as contact wheel, driving wheel, tensioning wheel, etc.) is very small, so there will be no unbalanced factors like grinding wheel.

In addition, the elastic grinding effect of abrasive cloth can greatly reduce or absorb the vibration and impact generated during grinding. The grinding speed is stable, and the abrasive cloth driving wheel will not be the same as the grinding wheel. The smaller the diameter, the slower the speed. The high surface quality of abrasive cloth grinding workpiece is mainly reflected in the small surface roughness value, good residual stress state, and no micro crack or metallographic structure change on the surface.

Abrasive cloth grinding precision is high. Due to the improvement of the production quality of abrasive cloth and the production level of abrasive belt grinder, abrasive cloth grinding has already stepped into the ranks of precision and ultra precision machining, and the maximum accuracy has reached less than 0.1mm. Because the abrasive cloth itself is very light, even if it breaks, it will not hurt people. Abrasive cloth grinding is not as serious as grinding wheel. 

Especially in dry grinding, the grinding debris mainly consists of the material of the processed workpiece, which is easy to recover and control dust. Abrasive cloth grinding has an extremely wide range of applications. Its superior grinding performance and flexible process characteristics determine that it has an extremely wide range of applications. Abrasive cloth grinding covers almost all fields from daily life to industrial production. Its various application forms and wide range are unmatched by any other processing method.

3. Difference between abrasive cloth and sandpaper

When buying sandpaper, you may see sandcloth, which looks similar to sandpaper and is also used for grinding. However, there are some differences between the two grinding tools, mainly reflected in the following aspects:

3.1 Different subbase

Sand paper is bonded to the paper substrate with adhesive, such as kraft paper, latex paper, water-resistant paper, etc; Abrasive cloth is made by sticking abrasive materials to the base of cloth, and the base of some abrasive cloth is made of paper and cotton cloth.

3.2 Different abrasives

Sandpaper and abrasive cloth use abrasive grains as abrasives, and the commonly used abrasives of sandpaper are mainly silicon carbide, corundum, etc; The abrasive of abrasive cloth is different from that of sandpaper. As abrasive, there are artificial emery, artificial corundum, quartz, light stone, iron oxide, etc.

3.3 Different particle sizes

In comparison, the abrasive particle size of sandpaper will be smaller and more delicate; The abrasive particle size of abrasive cloth is relatively large and coarse, but the grinding speed is fast and the efficiency is high, but the grinding accuracy is relatively not so high.

3.4 different prices

For products of the same specification and model, the price of sandpaper is usually cheaper than that of sandcloth, and sandpaper is more common when buying, and sandcloth is sold less.

4. Is abrasive cloth better or sandpaper better?

When polishing, many friends will have a question about which is better, sandcloth or sandpaper. Especially many carpenters don't know whether to choose sandcloth or sandpaper. In fact, sandcloth and sandpaper have their own advantages:

4.1 the advantage of abrasive cloth is that it is durable, not easy to drop sand, and can be folded around without breaking; The disadvantage is that the price is expensive, it is not easy to buy, and there are few delicate ones. The base of abrasive cloth is cloth, which has high strength. It is divided into soft cloth and hard cloth. The soft cloth can form a small abrasive belt, which is used by furniture factories to polish the edges and corners of small objects such as stools. Hard cloth should form large-scale sand belt, and coarse grained is used to polish excess wood for the first time.

4.2 the advantage of sandpaper is that it is cheap, has more types and models, and is polished more finely; The disadvantage is that it is relatively not so durable and easy to drop sand. Sandpaper is paper-based, with low strength, but it is fine grained. It is also used to polish wood. At the same time, it can be made into 9 * 11 hand sandpaper. It is generally used in furniture, wooden doors, especially in the floor industry. Only large units generally use paper-based sandpaper.

Generally speaking, abrasive cloth and sandpaper have their own advantages and disadvantages, which can be selected according to the workpiece material and grinding requirements. Generally, it is recommended to use abrasive cloth for coarse grinding and abrasive paper for fine grinding.