The huge popularity of mineral watts is explained, first of all, by their low cost and excellent operational characteristics. This material can be used to warm a wide variety of structures - walls, roofs and floors of private houses, pipelines, heating appliances, etc.
Process of creation
As a raw material in the manufacture of a material such as mineral wool plates, molten volcanic rocks, glass and blast furnace slag are used. This hot viscous substance is fed into a special centrifuge, in which (as a result of air purging) it turns into a fibrous mass. Next, binders are introduced into it. Usually phenol-formaldehyde resins play their role. Then sticky “cotton wool” comes under the rollers, forming an even layer from it. At the final stage, the material is cut into slabs of the desired size.
Mineral wool fibers can be arranged both in a chaotic order and perpendicular to each other. The last version of the material is called laminar, has a high density and degree of thermal conductivity, and is characterized by increased strength. Sometimes mineral wool slabs are glued on one side with thick aluminum foil.
Fire resistance
The main advantage of mineral wool in comparison with other insulators is its incombustibility. It is allowed to use this material for insulation of surfaces whose temperature reaches up to +400 degrees Celsius. That is why mineral wool boards are an ideal insulator for boilers and furnaces of various types. Basalt fibers begin to melt only after a two-hour exposure to a temperature of 1000 degrees. This is a very impressive indicator. As for the ambient temperature, this material can withstand 750 degrees without harm to itself . The combustibility group of mineral plates is KM0. The foil variety has KM1.
Degree of thermal conductivity
The main purpose of mineral wool is to protect homes, equipment and communications from the cold. The permissible coefficient of thermal conductivity of this material is determined by GOST 4640-2011. This indicator varies depending on the ambient temperature and can range from 0.038 W / (mK) at a temperature of +10 degrees to 0.070 W / (mK) at +300 degrees. Thus, in its ability to retain heat, this material is superior to many modern insulators. This quality is due to the porous structure with a huge number of air layers.
Density
This indicator for a material such as mineral wool heat-insulating plates can fluctuate in fairly large ranges (30-220 kg / m 3 ). The higher the density of the slab, the greater the distributed load it can withstand. According to this indicator, mineral wool can conditionally be classified into three categories:
- Low density (30-50 kg / m 3 ). Such cotton wool is mainly used for insulation of horizontal surfaces.
- The average density (60-75 kg / m 3 ). This variety is most often used to isolate various kinds of technical structures.
- High density (80-175 kg / m 3 ). Such plates can be used to insulate walls inside or outside buildings.
- Very high density (180-200 kg / m 3 ). This variety is usually used for insulation of roofs.
The density of a material such as mineral wool slabs is an indicator that determines only their ability to withstand loads. It practically does not affect the degree of thermal conductivity.
Moisture resistant
Low resistance to moisture penetration is one of the few disadvantages that mineral wool boards have. GOST to test the compliance of this material with standards in terms of water resistance requires special tests. At the same time, samples are taken from different places on the plate (20-30 grams). Then they are placed in a porcelain cup and calcined at a temperature of 600 degrees to remove organic impurities. Then the mass is ground into powder, moistened with a few drops of ethyl alcohol, after which a little hydrochloric acid is added. Next, the electrodes of the pH meter are lowered into the container. After ten minutes of stirring, measure the pH of the substance. The water resistance of the material is determined by the average pH value.
Mineral wool plates (GOST determines their water resistance in an amount of not more than 4-7 pH) absorb water quite well, while losing some of their thermal insulation properties. However, the degree of their moisture content by weight should not exceed 1%. To increase the resistance of the material to moisture it is impregnated with special water repellents.
Vapor permeability
The advantages of a material such as mineral wool boards include the ability to pass water molecules through it. The coefficient of vapor permeability of mineral wool is 480 * 10-6 g / (m * hour * Pa). Compared to other modern heaters, this is the highest figure.
Fiber arrangement
Mineral wool with a random arrangement of fibers has a specific gravity of 120-160 kg / m 3 and a tensile strength of 10 kPa. This variety is usually produced in slabs with a length of 120-160 cm and a width of 50-60 cm. Basalt wool with a perpendicular arrangement of fibers (lamella) has a specific gravity of 80-120 kg / m 3 and a tensile strength of 80 kPa. The dimensions of the plates of this variety are 120 x 20 cm. The thickness of mineral wool plates ranges from 30-100 mm.
Most popular brands
Most often in Russia, mineral wool of the Technonikol brand is used to warm structural elements of buildings. This manufacturer produces very high quality material that meets all GOST standards. Among other things, its undoubted advantage is its low cost.
Rockwool mineral wool boards are equally popular. Products of this manufacturer can be used for insulation of absolutely any structural elements and power equipment. Basalt cotton wool of this brand is available in a variety of sizes and densities.
Scope of use
Mineral wool slabs are used for insulation:
- sexes;
- ventilated facades;
- facades for plaster;
- roofing;
- walls from the inside and partitions;
- overlappings;
- pipelines;
- stoves and chimneys;
- boilers;
- production equipment etc.
Mineral wool - insulation is very effective and reliable. The combination of excellent performance and low cost makes it extremely popular with both individual developers and large industrial companies.