Emery cloth, it is also a sandpaper - these are the names of sandpaper, carpentry abrasive, which has no analogues today. The material is used in various industries and life from a construction site to an art workshop. Emery cloth is intended for manual and machine processing of wooden, plastic, ceramic and metal surfaces in the manufacture of various products to improve the adhesion of elements during gluing or to prepare the surface for painting.
What is sandpaper
Sanding paper is a combined material that consists of:
- The basis of sandpaper is most often - paper, fabric.
- Abrasive is a grain that is applied to the base with glue or resin.
Manufacture
Sandpaper production was first launched in China in the 13th century. The craftsmen glued river sand of different sizes to the parchment, crushed limestone, plant seeds with glue from agar-agar or starch. Later it was invented to use ground glass as an abrasive, from where the appearance of “glass paper” came from.
Serial production of sandpaper began in London in 1833, then it began to spread around the world, technology improved, and today we observe a variety of types of this product.
Production Stages:
- The paper base or fabric is impregnated with polymers, most often rubber latex.
- On the prepared base apply glue, heated to 30 ... 500FROM.
- The abrasive of the desired fraction is applied by the bulk method.
- They send the semi-finished product to the oven for drying. The temperature regime depends on the type of glue, grain fraction and other factors.
Thus, it is possible to make sandpaper of low quality at home using thick cardboard, crumb from an abrasive wheel or crushed glass, sand.
Release form
Finished products are stored by folding sheets in piles or rolling them into rolls. Sheet canvases have sufficient rigidity, so it is difficult to bend. Sandpaper in rolls is more compact in storage, its fraction and grain size is smaller than that of sheet.
Other forms of release:
- The abrasive mesh is a sparse web with fixed grain. When grinding, even the smallest dust particles pass through the material, do not clog in the pores. This method of work is called “dust-free grinding”.
- Abrasive wheels - fine-grained sandpaper, cut in the shape of nozzles on mechanical devices. Its purpose is to clean the surface of the metal from rust and remove the old coating.
- Emery paper of different grains, cut in the shape of a nozzle on electric tools with Velcro fastening or on holes made.
- Sanding belts for refueling in looping machines and machine tools.
Marking
Sandpaper marking indicates the abrasive fraction and concentration. Domestic GOST 3647-80 determines the number of grains of different sizes per 1 square unit, but this classification is considered obsolete. Today, the sanding pad complies with ISO international standards. This designation can be found on the back of the product.. It should be noted that the data of the old GOST and the values of international standards overlap with each other. Their correspondence can be traced in the table.
The main difference between the old and the new standards is the different movement of numbers in the marking:
- In GOST 3647-80, the values of grain size and density of grains are reduced, which is quite logical;
- In the new standard ISO 6344 (GOST 52318-2005), the product number increases with decreasing values in the marking.
Grain Decoding
The letter "P" in the designation indicates graininess. The larger the value behind the letter, the finer the fraction of the skin. P400 - the famous null. P600 ... P2500 have small fractions and an almost smooth surface, their granularity is not so palpable to the touch. This sandpaper is used for finishing polishing in industry.
In the old GOST, things were different. For example, 10-H: the first digit means that an abrasive with a particle size corresponding to a sieve with a 100 μm cell is applied to the surface of the product. The lower the indicator, the smaller the size of the screening.
Other designations
Types of sandpaper differ in the composition of the base and the properties of the grains. This information is also reflected in the product labeling.
- The letter "L" indicates the sheet form of release of the product. Roll is not designated in any way.
- The letter "M" stands for waterproof sandpaper.
- The product marked "P" is intended for grinding dry products without contact with moisture.
- “1” - an abrasive for soft surfaces, “2” - for hard ones.
To select an emery for a certain type of work, one should take into account not only the main classification, but also the information provided on the back of the sheet.
The basis
Abrasive paper can be made on different materials:
On sale you can find paper with a sponge base. This dust is well permeable, not afraid of moisture, suitable for manual and mechanical work for a long time.
Grit types by material
Abrasive is made on different bases:
- Silicon carbide (carborundum) is suitable for working with hard surfaces made of metal, plastic.
- Pomegranate grains have rigidity and softness at the same time: such abrasive paper is able to remove bumps from the surface of the wood and seal the fibers, so that the coating with paint or varnish lays evenly.
- Ceramics is used for the manufacture of coarse sandpaper used to level wood.
- Aluminum oxide is a material of considerable price, but its service life is impressive for its “tribesmen”: soft crystals break when polished, smoothing the surface, but smaller particles with the same sharp edges are formed in their place.
- Diamond sandpaper is the most durable and expensive. Almost does not wear out, it is used mainly for machine processing of products in industry.
Application
- Sandpaper for wood in carpentry is necessary when preparing the surface for painting or varnishing.
- In construction, sandpaper sanding strips on the plaster and putty, wood fibers before use. Also, the skin helps to get rid of smudges of paint.
- Car repair: cleaning old paint, preparing the surface for putty, gloss matting.
- In the manufacture and repair of furniture and in many other industries.
How to choose?
When choosing, you should pay attention not only to the cost, but also to the characteristics of the product.
- Grit material. The choice of fraction is carried out based on the purpose of the acquisition: for primary preparation of wood, P22 ... P60 skin is suitable. To prepare the surface of wood or metal for painting, choose P240 and smaller.
- Material is the basis. For long-term work, you should buy an abrasive on a fabric or combination basis. If you plan to manually align the surfaces, paper is also suitable.
- For manual labor, you can take a product of any format. For grinding machines and machine tools, it is more convenient to choose special circles or strips that do not need to be cut and glued.