Rus Articles Journal

For what thermal insulation is necessary?

mineral wool

, What is better: mineral wool or expanded polystyrene? Vapour permeability of mineral wool is six times better than

, than at expanded polystyrene. However if to consider that this indicator at a bearing wall is worse many times over, then the general vapor permeability of system depends on vapor permeability of a heat insulator a little.

If moisture is transferred much, and the finishing layer possesses low vapor permeability (as a rule), then all moisture will concentrate and be condensed in a layer of mineral wool. In process of a namokaniye of mineral wool its heat-insulating properties sharply decrease. Expanded polystyrene passes moisture approximately as much how many will be able to pass through basic and finishing layers, moisture in it does not collect, and the heat-insulating properties do not worsen.

From the point of view of fire safety mineral wool, certainly, is better. It does not burn.

Undoubted advantage of polyfoam is that it is possible to make various decorative elements of it. Agree that mineral wool is not suitable for these purposes.

Heat-insulating materials on a mineral basis

the Term mineral wool it is put into practice by state standard specification 4640 - 93 (DSTU B B. 2. 7 - 94 - 2000).

It is the heat-insulating material consisting of the thinnest (5 - 12 microns) of the fibers received by dispersion of fusions of silicate materials. Depending on a type of initial raw materials distinguish:

mineral (stone) wool - is made of mineral rocks: clays, limestones, basalts, granites, tuf;

slag cotton wool - is made of waste of metallurgical production - slags;

glass cotton wool - is made of glass.

Mineral wool consists of the mixed amorphous fibers. In its weight it is possible to notice a quantity of reguluses - not fibrous inclusions of spherical or irregular shape the size in millimeter shares.

The most qualitative mineral-cotton heat-insulating products receive from the melted rocks. Such mineral wool should be applied to thermal insulation of responsible designs and where special reliability of work of designs for many years is necessary.

The mineral wool received from domain slags, slightly worse. It is not so durable in the conditions of action of the raised loadings, humidity and sharp changes of temperature.

And here the glass cotton wool containing few not fibrous inclusions is elastic and well transfers vibrations.

Mineral wool is let out or in the form of a mat without filler, or in the form of plates in which fibers are linked among themselves by binding material for giving to plates of mechanical durability.

As a rule, as binding substance use fenolspirt and water-repellent oils, however concrete structure binding usually it is not disclosed.

Mats use in case it is necessary to arrange thermal insulation on the big square without gaps.

In front designs isolation is subject to mechanical loadings therefore in them use rather strong rigid and semifixed mineral-cotton plates.

Mineral wool not a goryucha that in combination with high warmly - and the soundproofing ability allocates it among other heat-insulating materials.

Besides it is steady against temperature deformations, it is possible to use it for thermal insulation of surfaces with a temperature from - 200 to +600, and, in some cases, and to 1000 C.

Chemical and biological firmness is inherent in its mineral nature, at the same time it is rather simple to utilize it after the end of life cycle of thermal insulation that is the indisputable advantage important for the solution of environmental problems.

Mineral wool has high resilience to mechanical influences, nevertheless, easily to process it - to knife or saw a hacksaw that facilitates installation.

A large lack of mineral wool - it is hydrophilic, well absorbs water therefore in case of its application in front thermal insulation it needs to be impregnated with special gidrofobiziruyushchy structures.

But mineral wool substantially of a paropronitsayem, thickness it is counted so that dew point it appeared in an external layer i.e. that moisture was condensed in a heat insulator, but not in a bearing wall.