What is the sandpaper: all varieties, especially the production and use

Emery cloth used for polishing various surfaces - removes small irregularities and burrs.

Sandpaper - the most common material for polishing various surfaces. There are many species and its brands. Do not understand them, you risk damaging the sanding material itself or abrasive - with me it happened once at the dawn misty youth.

After the unfortunate mistake I learned especially sandpaper, its types and labeling and in the future would not allow such oversights. I want to share this knowledge with you, so you can easily select the desired material, and the work went off without a hitch.

What is sandpaper?

Sandpaper- a flexible sanding material. It is also called sanding, sandpaper or a sandpaper. It is made of paper or fabric base and glued her layer of abrasive grains.

After processing the wood element sandpaper, you will make it smooth and suitable for painting.

Nazhdachka intended for surface treatment of concrete, wood, brick, metal, plastic, glass and other surfaces. With it you can:

• remove old coatings (such as paint, varnish) and their residues;
• to prepare a base for primer and paint;
• remove the chips and burrs from the slices of different materials;
• align, sanded, polished surface.

The skin helps to align the wall defects.

Abrasives production nazhdachki

Natural emery - a mixture of magnetite and corundum. Now he is in the manufacture of abrasives is almost never used.

Silicon carbide in nature, and it has to be synthesized.

1. Carborundum (silicon carbide) and corundum (alumina) - most commonly used for the manufacture of coated abrasives. Prepared their artificially.
2. Borazon (cubic boron nitride), synthetic diamond and grenades are used less frequently.

electrocorundum

Typically, the abrasive layer consists of grains nazhdachki corundum - on the photo.

Alumina is the most common abrasive. This solid crystals in which there is a break on the sharp edges:

1. Fused synthesized by reductive melting of the charge in an arc furnace. The raw material consists of iron filings, sinter bauxite and low-ash carbonaceous material.
2. At an alumina cutting ability. It can withstand high pressure.
3. Often to the charge during melting are added dopants. They improve the performance of corundum. For example, chromium oxide increases the strength and quality of the abrasive material. Aluminum oxide can be identified by the ruby ​​tone.

Carborundum

In silicon carbide grains sharp edges - this makes them an excellent abrasive.

1. Silicon carbide is prepared, sintering the graphite and silica in an electric oven Acheson. This crystals of different shapes, the faces of which have very sharp.
2. Silicon carbide is harder than corundum. But the fragility of it above.
3. The pressure during grinding crystals split. This creates new cutting edges. This feature keeps working carborundum nazhdachki long time and prevents clogging of the abrasive layer.

Sandpaper with abrasive silicon carbide is best suited for a treat plastic and glass. Also it can be used for metal.

Cubic boron nitride and artificial diamond

Artificial diamonds are quite expensive, so they are rarely used nazhdachki.

In diamond the highest hardness of all known substances. Elbor he loses a little in hardness, 3 times higher than for its silicon carbide and fused 4 times. But the cubic boron nitride on the temperature resistance of greater than diamond.

The disadvantage of these abrasives - their high price. Therefore, for the manufacture of emery cloth, they are rarely used.

Garnet

In the photo - garnet sand used as an abrasive.

Pomegranate relatively soft mineral. Its hardness on the Mohs scale is 6.4-7.5 units. Therefore garnet abrasive used for soft base materials. In most cases, it's wood.

Lack of pomegranate skins - rapid wear.

Dignity - in the same layer of abrasive grit. Therefore, this polishing sandpaper more smoothly than the materials with other abrasives.

Classification of sandpaper

Grit sandpaper y may be different, dependent on it, for which treatment material is used.

The most important characteristic of sandpaper — grain. nazhdachki purpose may be different:

• polishing,
• grinding,
• rough preliminary peeling.

Proceeding from it, the grain diameter can vary from 3 microns - for fine polishing, to 1 mm - for most coarse papers.

The Russian grain abrasives regulates GOST R №52381 / 2005.

Grit emery cloth covering international ISO №6344 (FEPA) standards. His counterpart in the Russian Federation - is the GOST R №52381 / 2005, adopted in 2005

According to these documents, the particulate material is indicated by letter P and a number from 2500 to 12. The figure above, the grain diameter is less. The sheer number indicates the number of wires in the mesh to one inch.

Often the skin is marked and the new and old guests, so you can not go wrong when it is selected.

In the CIS countries is still used by Soviet GOST №3647 / 80:

1. Thereon number indicates the minimum grain diameter in microns. After he put the letter N.
2. At first a small skin put the letter 'M, followed by a numeral indicating the grain size in microns.

In some countries, there are different standards:

• In Canada and the US - American National Standards Institute (ANSI);
• In China - GB-2478;
• In Japan - Japanese Industrial Standard (JIS).

Brand sandpaper grain size

The coarse sandpaper is designed for preliminary sanding surfaces.

Nazhdachka marked by two alphanumeric. They are printed on the back of the paint roll or sheet. The first one talks about the grain of the material. Types of sandpaper on the grounds presented in the tables.

coarse paper

Coarse sandpaper designed for rough work.

The fine-grained sandpaper

Fine-grained paper needed for fine grinding and polishing.

Finer sandpaper designed for delicate work.

Marking of skins on the state standard

The marking on the label material will tell you about him all the details.

The second marking indicates all data nazhdachkoy. It can be printed or placed on the paint label goods. Here is an example: L2E600 × 40P125A25-L1MA GOST №13344 / 79. Decode:

1. The first letter A means that the sandpaper sheet. The web material not designated.
2. Figure 2 indicates the type of paper. In our case it is intended for grinding on metal. Number 1 would mean that the skin is used for the treatment of materials with low hardness.
3. The letter E indicates that the abrasive is applied electrostatically. Letter M would mean the mechanical method.
4. 600 × 40 - this sheet dimensions, its width and length in millimeters. Roll skins, its width is given in millimeters and the length in meters.
5. Alphanumeric A1 says on the basis of material. In our case - it is resistant to moisture paper.
6. Marking P2 - is the foundation of paper 0-200.
7. Resistant to moisture paper denoted M, L1 and L2.
8. Do not water resistant paper labeled P1 and P11.
9. Base from twill fabric denoted S2G, S1G, C1 U2G, U1G, Y1 and Y2.
10. Fabric poludvunitka marked with the letter P.
11. Alphanumeric group 25A shows the type and brand of abrasive. In our case - it is white fused. It can also be referred to as 24A.
12. Marking 15A indicates normal fused.
13. 45A and 43A - mono-corundum.
14. 55C, 54C and 53C - black silicon carbide.
15. 62C, 63C and 62C - green silicon carbide.
16. 81Kr - flint.
17. 71St indicates abrasive glass.

Glass sand is optimal for grinding wood.

1. Figure 25 shows the grain diameter of the main fraction of the abrasive in micrometers.

Fine-grained skin is marked in this part of the alphanumeric group from M3 to M63.

1. H indicates the content of the main fraction of the abrasive. In our case - it is 55 percent.
2. The letter B would indicate 60%.
3. Letter D - by 41%.
4. The letter H - 45%.
5. The following letter shows how the composition is bonded abrasive. In my example - is M. So, hide glue was used.
6. The letter C will indicate a synthetic compound.
7. By means the combined mixture mezdrovogo and synthetic adhesive.
8. JAN-15 indicates the amber varnish.
9. SFC stands for phenol-formaldehyde resin.
10. The last letter shows class skins of durability in relation to the presence of defects. In my example, a class A - less than 0.5% defective surface material.
11. The letter B indicates less than 2%.
12. The letter speaks of less than 3% of the defects on the paper.
13. GOST №13344 / 79 points to the standard by which the material is made. On it is made water-resistant sandpaper. Do not water resistant material produced according to GOST №6456 / 82.

Classification by Method of abrasive distribution

Sandpaper backfilling with half (60% coated abrasive backing) prevents the formation of lumps in it.

1. Semi-open and open Coating. With this method of distribution of abrasive covers from 60 to 40% base. Such Coating eliminates filling the spaces between the grains of grinding waste. Lumps on the skins are formed.

Sandpaper with open and semi-open Coating is perfect for grinding of soft and friable materials. For example, resinous woods, filler surfaces.

Nazhdachkoy closed backfilling can grind metals.

1. The solid (closed) backfilling. With this method, the abrasive is applied to the entire substrate. This sandpaper is optimal for grinding hard materials. For example, hard wood species and metals.

base materials emery cloth

View emery cloth depends on the material and its foundations.

The paper substrate

The skin on plain paper is intended for dry sanding of surfaces.

Paper abrasive article should be as durable. So it will be for longer withstand the mechanical stresses. Classified paper, based on the density in grams per square meter. Adopted such a classification of ISO №6344. The marking is done with colored letters.

The grinding material on waterproof paper, the base allows you to wet grinding.

The paper may be plain and water-resistant. Its water-resistance and can be used to increase the abrasive glue.

Pros:

• low cost;
• when sanding it is not extended;
• surface of the paper makes it possible to apply to it the smallest abrasive grains.

Minuses:

• low strength;
• low wear resistance.

cloth backing

Emery cloth on the cloth, tougher, more durable than paper.

As a basis for nazhdachki polyester or cotton are most often used. Impregnated with polyester resin. Impregnation gives the material moisture and increases its strength.

Tearing strength and elasticity - these are the main characteristics of the fabric base. According to these parameters, they are divided into four classes:

1. Fabrics Group J - used for finish grinding profiles and edges.
2. Class X - used for heavy and dirty work.
3. Fabrics Y and W groups - is used if necessary maximum strength of the abrasive material. For example, when industrial grinding cladding panels.

When choosing a skin on the basis of tissue, in preference to the most rigid kind - so what will allow the forthcoming grinding and form oshkurivaemoy surface. The rigidity of the foundations depends on the durability of the abrasive material.

Advantages:

• increased strength;
• high wear resistance;
• moisture resistance.

Minuses:

• relatively expensive;
• when grinding lengthened.

For the production of certain types of sandpaper used composite material. It consists of paper glued to the fabric.

The basis of fiber

Grinding discs are made mostly on the basis of fibric.

Fiber base is intended for the production of grinding wheels. It is produced by treating the zinc chloride cellulose. The result is a dense and solid.

Lack of fiber - it nevlagostoykaya as strongly absorbs water.

Production of coated abrasives

In the production method uses two nazhdachki applying abrasive.

Methods of applying the abrasive grains

Abrasive material made electrostatically and more productive.

1. Electrostatic method. Negatively charged abrasive material is drawn in electrostatic field to be applied to the adhesive base layer. Under the influence of field particles are pressed into the binder. Grains are arranged vertically and the tip face down.

The advantage of the method - abrasive layer created by an electrostatic, more aggressive. It enables ground off more material (as compared to mechanically created abrasive layer) at the same physical effort.

In the method of manufacturing the mechanical grinding material maloproizvoditelen.

1. Mechanical way. The abrasive particles fall by gravity to the adhesive layer applied to the substrate. They are located in random order.

The disadvantage - abrasive layer created mechanically less aggressive.

adhesives

For the production of coated abrasives used synthetic and natural glues of different brands. Type of binder influences the strength and mode of use of sandpaper.

When insecure adhesive layer sandpaper quickly erased and lose performance.

The main task of glue - hold the abrasive on the ground and take off his heat during grinding. Durability grains fixing in the adhesive layer must be greater than the strength of the particles themselves.

The type of adhesive depends on the elasticity and stiffness of coated abrasives and to some extent the water resistance. The cement manufacturers often add special additives. They give the material a certain quality. For example, anti-loading, antistatic properties.

All water-resistant abrasive paper is made using synthetic adhesives.

1. Epoxy, urea-formaldehyde and phenol-formaldehyde resins, as well as amber varnish - the most common types of synthetic adhesives.
2. hide glue - used mostly natural composition. Skin, manufactured with its help, nevodostoykaya. Therefore it is not suitable for wet work.

Features of use of the material

Polishing the surface, follow the universal rule: you need to start treatment with a coarse sandpaper. Gradually replace it with a skin with a thin layer of abrasive.

Always start sanding with coarse sandpaper.

1. Very rough and coarse abrasive used for pre-treating wood, removing old paint layer and of corrosion of the metal.
2. Very thin and delicate skin used for different stages of finish grinding and polishing surfaces.
3. plastic best sanding material deposition of silicon carbide.
4. Wet processing You need to use water-resistant emery paper to form an abrasive layer of P-600 / P-400. Grinding in an aqueous medium makes it possible to achieve greater surface smoothness and suppresses dust formation.

For manual handling of bulk and surfaces of complex curvilinear form is most convenient to fix nazhdachku on a thick slicing of soft rubber.

This simple tool will increase the productivity and quality of your work.

Small instruction:

1. To work with the sandpaper was comfortable, wrap it around the bar. It can be of any suitable material - foam, plastic, or wood;
2. Pre glue or nail piece to the bar of porous rubber or felt.

With this simple device the quality of your work will grow. You will be able to control the pressure when grinding, and productivity will increase.

machine application

Sandpaper is consumable for such devices:

1. Surface (vibratsionnoshlifovalnaya) machine. At its working part rectangular sandpaper sheets are fixed with Velcro or clips. The apparatus may have a dust collector for withdrawal.

For deltashlifovalnyh machines produced sandpaper triangular shape.

1. Deltashlifovalnaya machine. Its triangular shape resembles the Greek letter Δ (delta). Device makes it possible to grind the surface in the hard to reach areas. It nazhdachki sheets in a triangle are fixed with Velcro. The device is equipped with a tap of the dust bag.
2. The orbital (eccentric) Grinder. On her skin in a circle is fixed with Velcro. The machine has a dust collector for the removal.
3. Angle grinders (Bulgarian) and a power drill with an additional nozzle. Emery circles on the support plate fixed by Velcro. Or are in the center of the hole under the clamping washer. Such a tool is no outlet for the dust collector.
4. Universal vibration cutter. On its support platform triangular sandpaper sheets fixed Velcro. The machine has no outlet to the dust collector.

On the surface of belt sanders can not just grind, but also grind.

1. Belt Sanders. Cuts roll skins are fixed on the roller and drive shaft device. The device is no outlet for the dust collector.

Output

Sandpaper - the optimum material for grinding work. Surface treatment to be effective and productive, choose the most suitable for the skin of your case - the types and the features I told nazhdachki.

Videos in this article will continue to acquaint you with the subject. If you have any questions, ask them in the comments.