Characteristics of asbestos board and its application

Asbestos cardboard is a modern material used as a heat-insulating element for baths and other objects with an increased level of fire hazard. Its density, weight, application features and characteristics of sheets with a size of 2-4 mm and 5-10 mm are recommended to be clarified in advance, even before the purchase is made. Asbestos cardboard can hardly be called a very popular product in the construction market, but it definitely deserves attention as an alternative to other fire-fighting materials.

The flexible asbestos cardboard produced in sheets belongs to the category of refractory protective elements used in industry, private housing construction. Its structure is formed from fibers of chrysotile asbestos - a natural mineral, supplemented with starch and minor inclusions of bakelite as a connecting substance. The material easily solves the problem of providing thermal insulation, while at the same time guaranteeing high fire resistance of buildings, structures, communication lines and nodes.

Several indicators can be attributed to the main properties of asbestos cardboard.

1. Resistance to prolonged exposure to high temperatures. Asbestos cardboard is not only able to operate when heated to +500 degrees, but also is not afraid of direct contact with fire. Its protective properties are extremely high, so the material turns out to be suitable for arranging stoves and fireplaces, as well as a gasket between structural elements with different coefficients of thermal expansion.

2. Lack of aging processes in the material. The estimated service life of 10 years practically does not exhaust the ability of asbestos cardboard to withstand external threats. Fibers retain their properties for much longer.

3. A wide range of mounting methods. It is possible to fix sheets in wet and dry ways, the material well covers all bends and corners, and other complex shapes. The tightness of the pre-wetting of the sheets increases. On top of it, it is possible to apply adhesive or finishing coatings.

4. Chemical resistance. It allows you to avoid deformation of the material under the influence of alkalis and acids, as well as when atmospheric temperatures drop to the freezing stage.

5. Mechanical strength. Sheets of asbestos cardboard are not afraid of breaking, stretching, and other influences, they can withstand intense operational loads.

6. Eco-safety. Even during combustion, heating, no hazardous substances are released into the atmosphere. Asbokarton has a high biological resistance, is not susceptible to the formation of mold, mildew.

Asbestos board is marketed in the form of sheets that meet certain safety and functional requirements. There are 5 brands of this material in total.

• KAON-1. It is intended for thermal insulation of surfaces exposed to maximum heating no higher than +500 degrees Celsius. Standard sheet dimensions in accordance with GOST 2850-95 are 600-1000 mm in width and 1 m in length, thickness 3, 4, 5, 6 mm.The material has a density of 1000 to 1400 kg / m3; no more than 15% of the mass fraction of the substance is lost during calcination.

• KAON-2. This includes general-purpose products with sheet sizes of 980-1000 mm in length and 740 to 1040 mm in width, with allowable thicknesses ranging from 3 to 6 mm. A grade designed for use as a connection element in assemblies requiring sealing. It can be operated at medium pressure up to 0.6 MPa.

• KAON-3. Asbestos board with this marking can be used in acidic and alkaline environments, it is produced with a thickness of 2 to 10 mm. This sheet material is mainly used for thermal insulation of walls, floors, and ceiling coverings in rooms. The wide size range makes it a good choice for preparing walls in the kitchen for the installation of built-in furniture, ovens and other heating appliances.

• CAP. Asbestos board of this brand is produced in sheets with a size of 460 × 780 mm, with a thickness range of 1.3-2.5 mm. It keeps its shape well, is used in industry in the manufacture of sealing elements for engines, machine-building equipment, units and communications for various purposes.

• KTM. Asbestos board of this type is distinguished by the complete absence of the ability to burn, charring, withstand high temperatures. Its technical characteristics allow it to successfully resist deformation in the longitudinal and transverse directions. This brand of asbestos cardboard is used to make muffler gaskets and other elements for mechanical engineering and the energy industry.

The weight of 1 m2 of asbestos board in kilograms corresponds to the indicators of its thickness. That is, a standard sheet of KAON-1 with a size of 10 mm will have a mass of 16 kg, 6 mm - 4.8 kg.

The use of asbestos cardboard implies the possibility of its adaptation to specific operating conditions. In a residential building, in a bathhouse, the use of general-purpose KAON brands is permissible. With the help of asbestos cardboard, pipes of heating devices are insulated, including during the construction of chimneys. In ovens, it helps to compensate for different thermal expansion rates between fireclay bricks and other masonry materials.

In the bath, sauna, the use of asbestos cardboard can provide a significant increase in the level of fire safety. The material provides complete insulation of surfaces, is able to withstand fire in direct contact with it. In boiler rooms, as well as in houses with stoves, fireplaces, it is advisable to use such a layer to prevent accidental fires, reduce the threat of fire.

Asbestos cardboard is also in demand in other areas of activity. Gaskets are made from it for individual units of machines and mechanisms that are exposed to intense heating. Besides, it is customary to refer to the areas of application of asbestos cardboard:

• metallurgy (as part of equipment);

• Housing and utilities;

• oil industry;

• refrigeration equipment;

• glass production;

• machine tool building;

• shipbuilding.

Furnaces and boilers for industrial use with such an addition ensure the minimization of heat transfer, the equipment does not overheat, and the loss of energy resources is reduced. This is especially true when operating equipment with an interrupted cycle.

Sheets of asbestos cardboard are well suited for leveling surfaces when laying gas, air duct communications. With them, you can perform the same operation under the brickwork, separating the outer casing and the lining of the furnaces. Fiberglass insulation can be mounted on top of such a lining.

In instrument making, the radio-electronic industry, asbestos board acts as an insulator. It does not conduct electricity. Provides additional thermal insulation between elements and materials.Resistance to combustion allows for maximum safety.

Asbestos cardboard is a versatile material that can be attached to the wall, wound on pipes. It can be mounted both dry and wet. Wherein sheets are easily adjusted to the specified dimensional parameters, they can be drilled, sawn, cut, exposed to any other influences.

If it is necessary to ensure a tight fit of the material to the surface on which it is to be fixed, its preliminary soaking helps to increase the adhesion characteristics of asbestos board. The sheets are placed in a humid environment for a while and then transferred to the place of fixation. After wetting, asbestos board acquires properties that are inaccessible to it in dry form:

• improved adhesion characteristics;

• high elasticity;

• preservation of the original volume;

• fixation density;

• good fit in corners and other difficult areas.

Wet mounting of asbestos board is suitable for covering horizontal and vertical surfaces. The material does not deform when dry, retains its original geometry. On top of it, you can attach any kind of non-combustible finishes. The high rate of moisture loss avoids long waiting times when fixing the material with pre-wetting.

The sheets are easily spliced ​​together in thickness with preliminary moistening. This allows you to obtain the required level of thermal insulation and sound absorption. The flexibility of the moisture-saturated workpieces ensures a snug fit on pipes and other complex substrates.

If you refuse to pre-soak, asbestos cardboard is attached directly to the surface. You can fix it horizontally, end-to-end, providing the necessary installation density, or mount it through holes previously made in the sheets with hardware. As an insulating material in the bathhouse, the boiler room is fastened with a gap of 20-30 mm from the wall surface. Asbestos cardboard is fixed on top of the lathing, then a standard finishing material with fireproof properties or a regular sheet of stainless metal.

When constructing a protective screen, this material acts as an additional thermal insulation layer, preventing overheating of the material. They are fastened without gaps, tightly, using special ceramic bushings. They do not heat up when the ambient temperature rises, they tolerate other influences well.

Sheets of asbestos cardboard should correspond not only to dimensional characteristics. They should not contain foreign inclusions, have traces of dents and other defects on the surface. When properly stored, the edges of the sheet should be flat, without signs of deformation, crumbling. Separate elements of the same size range and brand are allowed to be packed together, taking into account their brand.

1. KAON (1 and 2). In plastic bags or special paper. Transportation and storage is carried out with stacking in wooden boxes or on boards, pallets, with a strap.

2. CAP. As packaging, paper bags or film on a polyethylene base are used, with transportation on pallets. The strapping is carried out with polymer or steel straps.

Transportation of asbestos cardboard is allowed by any means of transport, without restrictions, but taking into account the recommendations for a specific method of transportation. During storage and transportation, the packing layer must not be disturbed. The material should be protected from contact with water, oil, and other types of contamination. The guaranteed shelf life is up to 10 years.