Mineral wool is a common insulating material. It is used by all construction companies and many owners of private houses who sheathe their homes on their own. But only a few know what it is made of.
Mineral wool is a group of fibrous materials produced from metallurgical slags and remelted rocks.
This definition refers to four types of cotton wool:
- glass fiber, or glass wool;
- stone;
- basalt;
- slag.
The composition of all subgroups is very similar. Their main difference is the size of the fibers of which they are composed. The difference in structure determines the technical characteristics of the material. Each type of mineral wool has its own parameters, on which the scope of their application depends. Its purpose is affected by thermal conductivity, wear resistance, resistance to moisture.
Each manufacturer makes mineral wool according to its own technology, so its composition and quality characteristics may differ:
- The basis of the material includes a variety of rocks. The products of metal processing are mainly used, which include carbonate rocks and gabbro-basalt compounds. Various additives are also added. The ratio of rocks and additives in mineral wool is 9:1;
- bentonite clay and phenol resins are used as a binder;
- almost finished insulation is covered with thin paper. As a rule, a combination of aluminum or polyethylene with kraft paper is suitable for this.
Varieties of mineral wool
Only four types are produced by factories - slag, basalt, stone and glass wool. Each group has its own distinctive properties, but basalt and stone have the highest quality parameters. The remaining types are budget material.
Slag wool - similar to glass wool and also has serious drawbacks. The material has residual acidity. It easily interacts with the metal and oxidizes it. Also, cotton wool quickly absorbs moisture and is not suitable for insulation of rooms, metal and plastic pipes. Slag prickly and very uncomfortable to use.
Glass wool is the most popular insulation. It is resilient and durable. Requires special care during use. Damaged fiberglass is easily inhaled by a person and settles on the lungs. To work with such cotton wool, it is necessary to use protective clothing, goggles, a respirator and gloves.
Stone wool - made from diabase and gabbro. Properties similar to slag. The material is not prickly, so it does not cause inconvenience during installation. Stone wool practically does not absorb moisture and is well suited for room insulation.
Basalt wool - also made from diabase and gabbro. The composition does not include blast-furnace slags and other impurities. The material is produced in rolls, which does not affect its structure and quality parameters. The properties of basalt wool are optimal for the use of insulation in many areas. This type of mineral wool is difficult to ignite. Upon contact with fire, its fiber will only melt.
Scope of mineral wool insulation
This material of all varieties is used in many industries:
- in construction as a building component;
- insulation of facades, premises, various types of structures and pipes;
- sound insulation of the building (mainly basalt wool).
Mineral wool board has gained particular popularity in application. The material in this form of release is easy to cut, convenient to transport. It is ideal for leveling surfaces and hiding imperfections in walls.
Main advantages of the product
- high fire resistance - non-combustible components of silicate rocks are used for production, which increases the fire resistance of wool. It does not burn at high temperatures and does not lose shape. A material with such properties is ideal for sheathing warehouses with flammable substances;
- chemical resistance - cotton wool does not react to chemicals. Therefore, it is sheathed in production workshops, laboratories and chemistry classrooms in schools;
- resistance to bioorganisms - fungus does not multiply in mineral wool, rodents and insect pests do not live;
- minimal shrinkage - cotton wool does not lose its original volume and shape over time;
- lack of hygroscopicity - certain types of insulation do not absorb water;
- high level of vapor permeability - water vapor does not linger inside the wool and passes through it. The room quickly loses unpleasant odors and the risk of condensation;
- excellent sound insulation - a layer of insulation protects the room from external noise;
- environmentally friendly product - is hypoallergenic and safe for people;
- ease of installation - a special production technology simplifies the installation of mineral wool. A novice builder can also cope with the process of warming;
- long service life - mineral wool will perform its functions and not lose useful properties for 70 years.
The harmful effects of mineral wool on humans
Despite all the advantages and functional features of the insulation material, mineral wool still has several disadvantages. The main disadvantage is the negative impact on the human body, subject to non-compliance with safety rules and personal protection during the installation of cotton wool.
Mineral insulation for a long time can be affected by temperature changes. As a result, its structure is destroyed and fine dust is formed. Through all sorts of holes and cracks in the wall, it penetrates into the living room, where people live and breathe this dust.
Of particular danger are artificial fibers with a size of less than three microns. Such small particles are not excreted from the body with exhalation, but are deposited in the lungs. Over time, the amount of settled fibers accumulates and the development of such unpleasant and dangerous diseases as bronchitis, dermatosis, benign tumors and oncology begins.
Harm to human health can also bring the composition of the binder resins, which include formaldehyde. They are often added to mineral wool to improve its quality. In addition to cotton wool, harmful resins also contain other building materials that may be present in a modern apartment - plywood, chipboard, and so on. Therefore, it is not surprising that in one room the level of formaldehyde content can exceed the norm several times.
The fact that the main raw material for its production is metallurgical waste also contributes to the shortcomings of mineral wool. At its core, insulation is considered environmentally friendly. But many manufacturers, in order to reduce the cost of manufacturing cotton wool, use industrial slags with a high content of such toxic elements as mercury, lead, cadmium.
In order to reliably insulate your home and not risk the health of households, you should purchase only certified mineral wool and only from trusted and conscientious manufacturers who produce their product in accordance with all international sanitary standards and requirements.
Mineral wool is a fibrous building material used in various types of external and internal insulation systems. It is made from melted glass, blast-furnace slag, lava rocks, the structure of the threads is set technologically. This allows you to control such technical characteristics of mineral wool as: thermal conductivity, density, hygroscopicity, vapor permeability. You can buy it in the form of plates, rolls, cylinders (to protect pipes), it is convenient to work with it - it weighs little and is easy to install.
The natural mineral base guarantees chemical resistance; . In many ways, the raw material and the geometric orientation of the fibers influence: strength, thermal resistance, moisture resistance and thermal conductivity. The values of the characteristics depend on the brand; basalt (stone) wool with a chaotic structure is considered the best.
Manufacturers Overview
1. TechnoNIKOL.
Products are represented by well-known brands:
- Rocklight - mineral wool slabs for thermal insulation of horizontal, vertical and inclined structures, most in demand in private construction.
- Teploroll - thick mats, rolled up, are great for warming attics and basements, ceilings.
- Technoblock - insulating boards with high sound absorption, used when installing siding or frame panels.
- Technoacoustic - mineral wool with enhanced sound insulation effect (absorbs at least 60 dB of noise), ideal for an apartment, office, club room.
This is the highest quality basalt wool with a small amount of phenolic resins, which is as safe as possible for the user. Excellent ability to retain heat and sound absorption, moisture resistance and low vapor permeability are the main advantages of the mineral wool of this company.
They produce mineralized fiberglass wool with different degrees of density (from 10 types on the market). Performance characteristics are exceptional: fine fibers form a strong and lightweight frame that recovers after compression or deformation, the lowest hygroscopicity of all mineral wool options. Isover Tel technology has made it possible to create a glass fiber that is pleasant to the touch (due to the significant density of threads at a minimum diameter). But grades of medium and increased rigidity due to the presence of films in the structure according to GOST 30244-94 are considered low-combustible (SG), their use has slight restrictions. The price of mineral wool of this company is acceptable, since recycled glass serves as a raw material.
It is made from quartz sand and belongs to environmentally friendly glass wool (confirmed by certificates). Advantages: flexibility, elasticity, ease and waste-free installation, protection against temperature changes, regardless of the season, excellent technical characteristics. On sale are 7 main varieties of mineral wool with different densities and tasks (a description of the properties and the recommended scope of application are indicated in the instructions), absolutely all of them belong to the NG class. This insulation provides a good fit to the structure, which makes it indispensable when laying a vapor barrier in a bath or thermal insulation of work surfaces at any angle.
Basalt-based mineral wool is used in private and industrial construction to protect various types of heat communications from freezing. The range is very extensive, the application temperature is from 180 to 1000 °C. The high price is explained by the versatility and quality: the mineral wool of this manufacturer has no restrictions and is even used for thermal insulation of food industry facilities. Assigned zero class fire safety, Rockwool has the ability to contain fire. Unique technical characteristics: high density (up to 90 g/cm2), no loss in permeability and composition purity, and almost zero hygroscopicity (material does not accumulate moisture). Mineral wool Rockwool is sold in ergonomic packages, it is profitable to buy it with a small amount of work.
Elastic mineral wool with a chaotic arrangement of fibers, in demand in frame construction, in systems with soft insulation. The advantages include: resistance to solvents of any type, excellent sound insulation, absence of asbestos impurities and chemical additives (no harmful substances are released during a fire). The material is vapor-permeable, so there is no accumulation of condensate on the walls even with frequent temperature fluctuations. As a result, Paroc mineralized wool insulation boards are ideal for interior decoration. There is only one drawback - the high cost, as with all types of molten rocks with a chaotic structure of threads.
Comparative description of the technical characteristics of mineral wool of different brands:
| Name of mineral wool | Thermal conductivity, W/m∙С | Water absorption by volume, no more than, % | Density, kg/m3 | Vapor permeability, mg/(m h Pa) |
|
TechnoNIKOL |
||||
| Technoblock | 0,035 | 2 | 40–50 | 0,3 |
| rocklight | 0,039 | 30–40 | ||
| Classic | 0,041 | 2 | 11–12 | 0,55–0,6 |
| Frame P37 | 0,034 | 12–35 | ||
| Glasswool M-11 | 0,041 | 1,5 | 9–13 | 0,7 |
| Glasswool P-30 | 0,042 | 16–18 | 0,55 | |
| Tech Mat | 0,036 | 1,5 | 35–50 | 0,5 |
| Tech Butts | 50–150 | |||
| eXtra | 0,036 | 1 | 30 | 0,5 |
| Uns 37 | 0,037 | |||
Expenses
The cost, taking into account the dimensional characteristics, is:
| Name of mineral wool | Size, mm | Volume in packing, m3 | Area, m2 | Number of plates, pcs | Price per package, rubles |
|
TechnoNIKOL |
|||||
| Technoblock | 1200×600×100 | 0,432 | 4,32 | 6 | 860 |
| rocklight | 1200×600×50 | 8,64 | 12 | 660 | |
| Classic | 8200×1220×50 | 1 | 20 | 1 | 1200 |
| Frame P 37 | 1170×565×50 | 0,714 | 14,27 | 20 | 1270 |
| Glasswool M-11 | 10000×1200×50 | 1,104 | 24 | 2 | 1420 |
| Glasswool P-30 | 1250×600×50 | 0,75 | 15 | 20 | 1510 |
| rockwool | |||||
| Tech Mat | 5000×1000×50 | 0,25 | 5 | 1 | 150 |
| Tech Butts | 1000×600×160 | 0,12 | 1,2 | 120 | |
| eXtra | 1200×600×50 | 0,504 | 10,08 | 14 | 960 |
| Uns 37 | 0,576 | 11,52 | 16 | 1230 | |
A review of manufacturers and a comparison of the technical characteristics of individual brands make it possible to make a choice in favor of mineral wool from molten rocks, as the most environmentally friendly, safe and multifunctional among heaters. But fiberglass is cheaper by about a third, if building codes allow, then with large volumes of work it is better to buy it. It is also important to follow the recommendations of manufacturers during storage and installation of mineral wool - despite its low hygroscopicity, it should be protected from getting wet.
The attempts of many residents of houses to increase the comfort of living in winter motivated the installation of efficient heating systems. But a stable temperature in these cases borders on increased energy costs. And the whole house solves two problems at the same time - maintaining a stable temperature regime and minimizing heating costs. At the same time, a good indicator of sound insulation is also achieved.
Specifications of mineral wool
Mineral wool is known for having one of the most effective thermal conductivity indicators. If we compare it with similar parameters of other heaters, then mineral wool is on the same level in terms of efficiency as polystyrene and significantly outperforms many other heaters.
- The coefficient of thermal conductivity of mineral wool for its different variants ranges from 0.036-0.042 W / (m * K). This parameter is affected by the density of the insulation
- The density of mineral wool is set by the manufacturer depending on its functional purpose and form of release. Standard indicators are 100,150,200 kg/m3. The higher the density, the more efficient the material's ability to retain heat.
- Another important characteristic of mineral wool is its ability to withstand the influence of biological forms. With sufficient convection, mineral wool is not the best place for the development of fungal forms and molds.
- The property of mineral wool regarding hygroscopicity also plays a role in its functionality. Moisture does not accumulate on its fibers and freely penetrates through them. This circumstance gives reason not to be afraid about the displacement of the dew point into the thickness of the insulated surface. In addition, relative hygroscopicity allows the material to be used for ventilated facades.
Important! Although mineral wool fibers do not absorb moisture into themselves, they are able to retain it in the structure of the material between the fibers. Therefore, it is recommended to use this material only when insulating the outer part of the building or inside the wall structure.
- An important positive property of mineral wool is its resistance to high temperatures. The ignition of the material is practically excluded, since the phenol-formaldehyde resins included in its composition do not have a tendency to burn. Even at the risk of fire, mineral wool fibers do not light up, but only melt slightly, while maintaining temperatures up to 800 degrees
- Regarding the heat capacity and the ability to retain heat, the fact that mineral wool can withstand a temperature drop to -160 degrees without consequences is evidence.
However, when insulating with mineral wool any structural surfaces of a building, it must be borne in mind that mineral wool undergoes deformation over time, forming cold bridges. However, such manifestations can be expected after 8-10 years of operation.
Another disadvantage of mineral wool is that its fibers are accessible to rodents. And although they are not interested in the material as food, they can arrange their nests in the thickness of the insulation.
Mineral wool is used for warming not only private houses, but also apartments, as well as its individual parts. If you live on the first floor and know, then you can insulate it from the outside with mineral wool.
For the inner walls of the balcony, foam is more often used. Read about which is better (foam or mineral wool). The article provides a detailed comparison of these two materials.
What types of mineral wool are produced today
The production of this insulation is based on the use of mineral components that have identical properties. The structure of each type of mineral wool is a chaotic interlacing of fibers, which contributes to the adhesive strength and insulating properties.
The most common types of mineral wool today are:
- stone wool
- glass wool
- slag wool
Despite the general parameters, these categories of mineral wool have some features.
glass wool
This category of mineral wool is produced by melting several components:
- Sand
- Limestone
- Dolomite
As a result, a material with a thermal conductivity coefficient of 0.038-0.040 W/m*K is achieved. In this case, the resulting length of the fibers reaches 0.5 cm, and their thickness is 12 microns.
Glass wool is one of the first materials in this category. It has all the inherent advantages, but has one significant drawback.
Glass wool in the structure of the fibers contains the smallest particles of glass, which very often injure workers during the insulation process, so the main requirement when working with mineral wool is to take precautions.
Otherwise, this material is suitable for insulating floors, walls, roof structures.
slag wool
The characteristics of this type of mineral wool are somewhat more modest. The reason for this is its active ingredients. Slag is made from blast-furnace waste. Waste slags go through the same processing steps as in the glass wool production process. In this case, fibers up to 15-16 mm long and 5 to 8 microns in diameter are formed.
- Slag wool components contain high residual acidity, which can react with metal components and cause corrosion.
- The thermal conductivity of slag wool is slightly higher and is 0.048-7-0.052 W / (m * K). The fire resistance parameters are also less attractive - slag wool is able to withstand temperatures up to 400 degrees, after which it begins to deform
stone wool
In recent years, this material has become the most popular among analogues. Stone wool is made from basalt rocks. , or rather, its thermal conductivity is the most effective - from 0.032 to 0.038 W / (m * K).
It has stone wool and sufficient density, which increases the period of its operation up to ten years. It is less prone to deformation and does not pose an environmental hazard. Temperature resistance is also high - it can withstand up to 900 degrees.
When choosing mineral wool for insulation, you need to take into account the conditions of its operation and location. Insulation in the form of mats will last longer and provide a greater level of heat capacity.
It is necessary to pay attention to the density and thickness of mineral wool. The price of mineral wool is often justified by its technological characteristics, but this is not a decisive feature in the choice of material.
When buying, you need to pay more attention to the indicators of thermal conductivity and vapor barrier.
And then it will be possible to confidently stay for many years in a comfortable environment with a stable temperature in any frost outside the windows.
Video about the characteristics of mineral wool
Characteristics of Rockwool stone wool. Benefits of stone wool
How glass wool is made. The process of manufacturing fiberglass thermal insulation in production is shown.
What is slag wool, how it is produced, its main technical characteristics, pros and cons, features of the choice of material, an overview of manufacturers and brief instructions for installing a heater with your own hands.
Description and features of the production of slag wool
Slag is made from blast-furnace slag, which is a waste of metallurgical production. In the years of the USSR, almost all large metallurgical enterprises operated workshops for the production of slag wool. Investments in this production are minimal, and the practical benefits are obvious, it is possible to get rid of waste and produce insulation for the needs of both the plant itself and civil engineering.
For the production of slag wool, as a rule, acidic (viscous) blast-furnace slags are used. They contain such harmful compounds as iron oxides, sulfurous substances, manganese. If the sulfur content is more than one percent, and the lime is over forty, then the finished insulation will decompose over time. In addition, the presence of sulfur will contribute to the appearance of rust on the iron elements in contact with the heat insulator, especially when it gets wet.
The slag wool insulation consists of a thin mineral fiber with a diameter of approximately 0.002-0.005 millimeters and a length of up to 60 millimeters. Also, the composition may include slag dust and small balls. However, their presence in the structure of the heat insulator indicates a low quality of the material.
Such threads are obtained by blowing a jet of fiery liquid slag with a powerful jet of steam or compressed air. In addition, often the slag also goes through the stage of mixing and enrichment with silica. After the fibers are formed, they are pressed and treated with a binder. Next, the material is formed into sheets.
Specifications slag
At present, slag wool is used much less frequently than during Soviet construction. It was replaced by a new generation of fibrous heat insulators. However, this material has generally good technical characteristics, which allows it to be used so far.
Consider the characteristics of slag wool:
- Thermal conductivity. This parameter depends on the density of the insulation. On average, it is 0.46-0.48 watts per meter per Kelvin. The smallest coefficient is achieved with a mounting density of 350-450 kilograms per cubic meter. The thermal conductivity of slag wool is the highest among all types of mineral fiber heat insulators.
- Hygroscopicity. The coefficient of sorption moistening is 1.9%. This means that slag wool absorbs water well and practically does not have a water-repellent ability.
- Soundproofing. According to this indicator, slag wool is similar to all other varieties of mineral wool - 0.75-0.82. This means that the material is quite suitable for creating a sound-absorbing layer. But this insulation is not able to absorb vibrations.
- fire resistance. The material belongs to the NG category, that is, it is not capable of burning.
- Sintering temperature. Despite the fact that slag wool does not burn, it has a rather low sintering temperature. When exposed to 250-300 degrees above zero Celsius, the insulation begins to melt. As a result of such exposure, the material loses its thermal insulation qualities.
- Environmental friendliness. Slag wool contains phenol-formaldehyde resins. In high-quality insulation, their concentration is minimal. However, it is important to observe safety precautions when working with this material and the technical conditions of use.
- Biological stability. Slag wool does not attract rodents, insects, microorganisms.
Advantages of slag
In general, the advantages of using slag wool as a heat insulator are the same as those of all other fibrous insulation. The advantages include the following factors:
- Good thermal insulation. The material has good heat-saving properties. Slag wool is slightly inferior in this parameter to stone and glass wool, however, with proper installation, it also reliably protects the building from cold wind and freezing.
- High sound absorption coefficient. As a soundproofing material, slag wool can be laid both on external walls and on interfloor ceilings. It will reliably protect against the penetration of extraneous sounds from the outside due to its own fibrous structure, in which air is retained and sounds are suppressed.
- low price. Slag wool is a fairly budget material. This is due to the fact that waste from the metallurgical industry is used for its production.
- Ease of installation. It is possible to lay a heater both on equal, and on curved surfaces. It is also easy to cope with the installation of a heat insulator on round objects. It's flexible enough. In addition, the weight of the slag wool is small, so even one person can do the installation work.
- Long service life under optimal conditions. If slag wool does not get wet and exposed to high temperatures, then it is able to maintain excellent sound and heat insulation characteristics for 50 years or more.
Disadvantages of slag
This is a specific material in which the percentage of residual acidity of blast-furnace slag is high, which makes the insulation not as practical as other types of mineral wool.
In addition, the disadvantages of slag wool include the following:
- Poor resistance to sudden temperature changes. Insulation can lose its thermal insulation properties if it is often subjected to temperature fluctuations.
- Good ability to absorb water. This factor provokes a number of negative aspects. So, when wet, slag wool ceases to function as a heat insulator. In addition, when moisture gets on the material, an acid is formed that corrodes metal parts, fasteners and elements.
- Limited scope. Slag wool is not recommended to be laid as a heater on buildings where there is a high level of humidity (baths, saunas), building facades due to the risk of getting wet. In addition, wooden houses should not be isolated with this material either. If it gets wet, then the tree under the layer of heat insulator will rot.
- High brittleness and sharpness of fibers. Like glass wool, it has sharp and brittle fibers that are dangerous when it comes into contact with open areas of the skin and mucous membranes. Therefore, it is necessary to work with the material with the obligatory use of protective equipment.
- Low vibration resistance. With strong vibration loads, slag wool will settle, and its thermal conductivity will increase.
- The presence of harmful substances. Many low quality insulation materials contain volatile chemical compounds such as phenol formaldehyde.
Slag wool selection criteria
When choosing slag wool, you should, first of all, pay attention to the material from well-known manufacturers, which has good reviews. In no case do not buy insulation from little-known brands at dubious points of sale, where you cannot be provided with the entire list of documents, certificates and licenses for the product.
- The highest quality mineral fiber insulation is offered by German manufacturers. Only they have the most picky certification bodies that will not release low-quality or potentially dangerous goods on the market.
- Check with the seller in which direction the fibers of the heat insulator are located. When placed vertically, slag wool will store heat well and absorb sound. With chaotic - it will be more durable and withstand dynamic loads.
- Check the GOST of the product on the packaging if domestically produced slag. Its presence guarantees the quality of products.
- Choose the material that best suits your needs. The density of slag wool can be different, and the scope of its use depends on this. Density of 75 kilograms per cubic meter is suitable for roof insulation, attics. Material with a density of 125 kg / m 3 is used on the floor, ceilings, interior walls.
Price and manufacturers of slag wool
Many large manufacturers of mineral insulation are gradually abandoning the production of slag wool. Those that still produce it have a limited range.
Worthy of attention are such domestic manufacturers of this insulation: Minvata CJSC, Techno Plant LLC, Minplita Plant CJSC, Thermal Insulation Products Combine LLC.
In addition, local representative offices of major brands such as Rockwool, Isoroc, produce a series of technical heat insulators based on blast-furnace slag.
The price of slag wool is about 500 rubles per pack.
Brief instructions for installing slag wool
Given that this insulation can react critically to moisture, it is not recommended to install it on the facade of the building. Also, do not attach slag wool to a metal frame. If you plan to insulate vertical or inclined surfaces, then use a wooden crate.
The installation scheme of the heat insulator is as follows:
- We prepare wooden bars measuring 50x50 or 50x100 millimeters. We select the thickness and width taking into account the width of the insulation.
- We fix the waterproofing to the surface using building brackets, with an overlap of 10 centimeters.
- In order not to cut slag wool once again and not to raise harmful dust from microparticles of fibers, it is recommended to install the crate in increments of the width of the mat. Usually it is about 50 centimeters.
- The slabs must fit snugly into the holes between adjacent beams and fit end-to-end.
- The heater does not require additional fastening.
- We lay a vapor barrier on top of the slag. We also fasten it with an overlap and glue the joints with special adhesive tape.
Watch a video about the production of stone wool:
Slag wool today is the least popular among all varieties of mineral fiber insulation. According to its characteristics, it is inferior to many new thermal insulation materials. However, the material is still used to isolate non-residential and industrial premises.
10.08.2017
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Mineral wool is one of the most popular heaters on the building materials market. It is used almost everywhere from private houses to water mains. This is not surprising, the material is cheap, easy to install and effective, but is everything so simple with it? Let's figure out what mineral wool is, how to choose and apply it correctly.
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Types of mineral wool and production features
Despite the fact that several heaters are called mineral wool at once, they all differ both in composition and in their properties. These include:
- Slag.
As you can see, the composition of mineral wool varies greatly, but what unites it? First of all, it is the structure of the material. Mineral wool consists of thin fibers woven together. They are tightly packed to increase strength. The result is a flexible and strong structure with empty space between the fibers. It is filled with air, which provides thermal insulation. The density of mineral wool remains quite low, which greatly facilitates its installation and transportation.
Glass wool is the most famous, but far from the most popular type of insulation. It is made from recycled glass with the addition of sand, lime and several other chemicals. The mixture is poured into the furnace, where it is melted to a fluid homogeneous mass. The resulting substance is blown under high pressure or with the help of a centrifuge through a fine grate, and fine fibers are formed.
The red-hot threads settle in a special chamber, where a large dense thread is formed from them. In this state, they are not yet connected to each other and easily break up. To fix the structure on the fibers, a binder mixture is sprayed in an even layer. Most often, phenol-formaldehyde resin is used for this. The resulting structure is compressed and sent to cool. So cotton wool takes on a familiar look, but it is not yet ready for use. It is coated with a polymer composition and sent to the oven for repeated heat treatment, but this time softer. The last 2 operations give mineral wool boards high strength and resistance to constant temperature changes and high humidity.
The production technology of the other two types of mineral wool is similar, the difference lies only in the composition. In stone wool, basalt rocks are used as a base, and waste from ferrous metallurgy is used to make slag wool. It is clear that the structure of mineral wool-based heaters remains the same, but we will figure out what the composition affects.
The most flexible type of mineral wool. Features of the composition allow the production of material of different densities. Because of this, the density of rock-based mineral wool varies greatly. A denser material is used in cases where high strength is required from it. It is sheathed with metal structures in industrial premises, pipes, loaded structures made of reinforced concrete and other elements subject to constant fluctuations or temperature changes.
Mineral wool from stone rocks is produced both in rolls and in rigid molding. If everything is clear with the use of the first type of material, then molded insulation is used to close pipes and vibrating elements. It provides a tighter contact of the mineral wool with the surface, which ensures sound insulation. In this case, it is necessary to choose not only the grade of the material, but also its shape so that it matches the surface to be insulated.
Stone mineral wool is used in cases where high strength is not required from it: in collectors, on technical floors, roofs. In addition to the lower price, its advantage is also that the flexible material is easier to mount.
Another plus of stone-based insulation is resistance to temperatures up to 800 degrees. Therefore, it is used not only as a heater, but also as a fireproof coating.
In some cases, stone mineral wool is produced with foil. A thin layer of metal significantly increases the strength and durability of the material, and also improves moisture insulation.
A cheaper type of thermal insulation, characterized by a characteristic yellow tint. It is used in cases where increased requirements are not imposed on the strength of the coating.
A significant drawback of glass wool is a prickly surface. The insulation consists of many thin pieces of glass that dig in. The small length does not allow them to cause serious harm to a person, but pieces of glass remain on the skin after contact, which can lead to chemical burns. Because of this, it is impossible to work with it without gloves, and it is advisable to use safety glasses as well. Glass wool cannot be used in residential premises and spaces where people constantly work.
Most often, glass-based mineral wool slabs are mounted under ventilated facades. There they remain protected from mechanical impact and human or animal contact with them. Often it is used for thermal insulation of pipes. In this case, mineral wool mats are used, which are wound on a cylindrical surface. Outside, they are sheathed with a dense mineral tissue and fixed with wire or bundles.
slag wool
A material that is used less and less. It is produced from slag formed after metal smelting in a blast furnace. As you might guess, this significantly reduces the cost of the insulation, but its properties are not the best either. Both the thermal conductivity and the chemical resistance of the material suffer.
Slag mineral wool is produced only in rolls. Due to the low rigidity, the material does not hold its shape well, so plates from it are not molded. The main disadvantage of slag wool is vulnerability to moisture. Under the influence of water, chemical reactions begin to occur in it, and the integrity of the fibrous layer is broken over time. Over time, slag in the open air simply turns into rags. As you might guess, the service life of mineral wool from slag is significantly lower in comparison with analogues. Slag wool is being produced less and less, and it is usually used only for insulating warehouses and garages due to the low cost of insulation.
The main characteristics of mineral wool
Let us immediately highlight several main criteria by which thermal insulation is selected:
- thermal conductivity;
- combustibility;
- density;
- vapor permeability;
- soundproofing.
The main indicator is the coefficient of thermal conductivity of mineral wool. It is measured in W / (m * s) and usually ranges from 0.03 to 0.045. The lower the value, the better. It is the thermal conductivity of mineral wool that characterizes its main function - the ability to reduce heat flow through the insulated surface.
Often the quality of waterproofing is also important. It is characterized by a vapor permeability index, which is measured in g / (m * h * hPa). The higher the value, the better the insulation passes moisture, and it is not so clear. Somewhere good ventilation is required, and somewhere vice versa. Initially, mineral wool passes water well, therefore, in cases where waterproofing is required, it is necessary to use foil mineral wool.
Due to the fibrous structure of mineral wool, it also copes well with damping sound vibrations. The quality of sound insulation is indicated on the packaging with the AW marking, the value of which varies from 0 to 1. The closer the indicator is to one, the better the material dampens sound waves.
Soundproofing and insulation of concrete floors with mineral wool.
The density of mineral wool affects all of the above characteristics, but it is not indicated on the packaging for this. The indicator is used to calculate the weight of the structure, so, other things being equal, lower density is a plus.
The last significant characteristic of mineral wool is combustibility. The material is non-combustible and has good heat resistance. It holds the structure and does not emit toxic substances at temperatures up to 650 degrees, and to increase fire safety, a special resistant mineral wool is produced with the appropriate marking on the package.
Choice of mineral wool
We have already figured out the features of the production of mineral wool and its properties, it remains to understand what criteria to choose a heat-insulating material by. One of the key criteria is always the price. It's easy to choose quality material, but why pay for features you'll never need?
First, decide where you are going to use the insulation. Mineral wool made of glass under plaster is an excellent option for facade insulation. And also glass wool can be used in technical rooms or for pipe insulation. Despite the lower cost, it does an excellent job.
For industrial premises and internal insulation of houses, manufacturers recommend using rock-based mineral wool. It is completely safe for humans and tolerates constant vibrations well. In places where waterproofing is required, it is better to use mineral wool with foil.
As for the slag, it is better not to buy it. The material is outdated and does not justify even its low cost. Saving on thermal insulation, you run the risk of having to redo it in the future.
It is worth remembering that the main indicator that you should look at when choosing a material is the thermal conductivity of mineral wool. You buy a product for thermal insulation, and it is this parameter that characterizes it. The remaining indicators are already selected for a specific object.
Now you know almost everything about mineral wool, its features and what it is. It remains only to choose a suitable brand of thermal insulation and a store. In the event that you are not sure what exactly you need, it is better to contact the builders or an experienced designer for advice.
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