Panorama on the insulation of buildings
The insulation is a technique with which to isolate two systems having different environmental conditions, so that the two systems do not exchange heat or vibration between them.
In particular, the insulation can offer sound insulation, thermal or acoustic.
Typically the insulation is carried out by interposing between the two parts of special materials which do not allow the exchange of heat, in the case of thermal insulation, or the exchange of vibrations, in the case of acoustic insulation.
The insulation is of great importance in many industrial processes, for technical reasons, but also in the home, especially for the new and ever more necessary criteria of energy efficiency of a home.
This certification has been established with the European Directive 2002/91/EC.
Adequate insulation of the walls of a building allows to reduce the heat flux outgoing from the internal environment (home, environment to keep warm) to the outside cold, in the cold season.
Conversely, during the warm season prevents the flow of heat penetrating the building (the inside to keep cold).
The materials used for the thermal insulation
The materials used for the thermal insulation are so-called thermally insulating materials, namely all those materials that are characterized by a low thermal conductivity. In principle, an insulator is a material with a structure of dense cells, and those cells is contained in a gas with low thermal conductivity.
Examples are the solid waste output from the blast furnace (used for the extraction of some metals such as iron, from its minerals).
These, after suitable treatments, are also employed for the thermal and acoustic insulation.
The materials normally used for the insulation of the pipes are the rock wool, foamed elastomers and polyethylene foam.
For the isolation of the walls of the buildings are used natural organic materials (cork), inorganic (glass fiber) or artificial (expanded materials such as phenolic resins, polyurethane, polystyrene).
Electrical insulation materials plant
The cork is produced from the bark of a Mediterranean plant, the cork oak (Quercus suber). From the pulp clean the bark yields an granulate, with different sections, can be used without further processing as an excellent insulating material in cavities of walls, floor and roof, or tied with lime or vitrifying specific minerals, in the screed subfloor. The granulated cork may also be agglomerated into panels for the combined effect of heat and compression. To be of good quality cork granules must be free of woody debris, soil and dust, these elements would favor the onset of mold. The cork panels shall not be bonded with synthetic glues that in addition to their hazard (sale of formaldehyde) greatly reduce the main qualities of the material but by the ability of self-adhesive suberin, the resinous material, which undergoes color melts tying the course granules after cooling. The cork panels toast or foam have excellent insulating ability, but do not use synthetic glues that the high temperature at which the raw material is subjected burns suberin and the tannin releasing benzopyrene natural product but toxic and foul-smelling. Even in the case of cork are therefore fundamental certifications and quality control on the product. In summary, the cork is an excellent insulating material for sustainable building only if it comes from pure pulp cork bark devoid of any foreign element, ventilated and possibly aggregate in panels for only the combined effect of heat and compression, In this case its characteristics are the excellent thermal and acoustic insulating power, the great breathability, water resistance, the unassailable by insects and rodents.
The wooden mineralized
With the wood fibers (typically poplar, fast-growing plant) panels are manufactured with excellent quality bioedili, The production process is based on the use of magnesium oxysulfate (caustic magnesite and magnesium sulfate) substance that impregnates, binds and mineralize the wood fibers. A mixture of wood fibers and magnesium oxysulfate is subjected to high temperature and compression and then formed into panels. In this way, the wood loses the organic perishable and is mineralized assuming in addition to its already known properties of acoustic and thermal insulation, breathability, hygroscopicity and unassailable by insects and rodents, an excellent fire resistance.
The panels in wood fiber
From sawmill waste (recycling of bark and branches of conifers is not chemically treated) comes from wood fiber, raw material for the production of insulating panels, wood fibers are aggregated without compression due to the adhesive properties of the lignin present in the natural resin fiber itself. ] The resulting product is completely biodegradable and recyclable, and is excellent for diverse applications in acoustic and thermal insulation of floors, walls and roofs.
Recycled cellulose fiber
Other material with good ability to thermo-acoustic insulation and with the excellent quality of recycling is coming from the cellulose fiber obtained by a special technique of paper converting the newspapers that, thanks to the use of natural mineral components typically boron salts), , makes it non-flammable, resistant against mold, rodents and insects. The material is blown in the cavities of walls and roofs.
Coir, jute, cotton, flax
Not very common but certainly interesting for their ecological characteristics (renewable raw materials, recyclability, etc..) And their qualities of insulation materials are derived from other vegetable fibers such as coconut, jute, cotton, linen. Of course, these materials must be accompanied by adequate guarantees and certifications as to their origin from crops in which no use is made of chemicals.
Insulating materials of animal origin
Thanks to its unique microstructure sheep's wool is a perfect and natural alternative to mineral fiber for thermal and sound insulation. In addition to the qualities of the wool insulation and breathability has great qualities of hygroscopicity, ie it is able to absorb water up to 33% of its weight without appearing wet and slowly release the water absorbed thereby playing optimally the task of balancing the 'relative humidity. Wool is a renewable and recyclable raw material with a very low energy balance (energy input during production).
Mineral insulating materials
Some mineral raw materials have physical and interesting techniques for their use in green building, obviously if not with additives with synthetic products derived from petrochemicals.
The hydrous calcium is a porous material, produced in autoclave starting from siliceous sands, hydraulic lime and a small percentage of cellulose fibers with a reinforcement function. With this material you realize lightweight panels, very resistant to compression, high dimensional accuracy and easy workability, non-flammable and very resistant to fire, free of radioactivity and the emission of dust or other irritants, breathable and recyclable (for the production of cls).
Are obtained by crushing and subsequent expansion due to high temperatures of micaceous minerals to vermiculite and perlite for a volcanic rock. You can use dry as filling in gaps but also as aggregate for lightweight insulating plaster with good performance of thermo-acoustic insulation. It should be ensured the absence of radioactivity. Although natural sources are not very advisable in green building, except in very special cases, the conformation of fibrous mineral insulating materials.
Mineral fibers: rock wool, glass wool, asbestos
The danger of microfibers, after decades of indiscriminate use, it is now clear to everyone by now unfortunately (asbestos). Great attention should however be paid to the use of high fibrous mineral that can be released in the air microfibers particularly irritating to the mucous membranes of the respiratory system. In the production and packaging panels of these materials are used for other adhesives products of petrochemical origin.
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