Polystyoltilol has another more common and known name - foam. His appearance is also known for a long time. This lightweight material that rests on the water, because air chambers have inside its white balls. It is they who give the material unique properties. He has shortcomings. It is fragile and easily flammable.

Polystyrene foam is a gas-filled material that is made from polystyrene and is used as a heater.

The manufacturer produces it in sheets that have different lengths, width and thickness.The last parameter is the main thing in choosing this material. The product thickness can be from 20 to 100 mm. This material is very popular with builders. It is used to increase thermal insulation during brickwork with full-scale bricks. The pieces of foam plastic are put under the Paneru, which is separated by the floor under parquet or laminate. They can be insulated the walls outside during the decoration of the walls of plasterboard. Most often it is used from the outside.

Foam sheets can be standard and non-standard size.

The length and width of the standard sheet is 1000, 2000 mm. The manufacturer can cut products and other non-standard sizes. Often you can find sheets of 1200x600, which meet the needs of the buyer and are in good demand. It can be a sheet with dimensions in 500x500, 1000x1000, 1000x500 mm. Custom order can be obtained by a batch of polystyrene foam having parties 900x500 or 1200x600 and other dimensions that does not contradict standards. GOST allows you to cut the products by 10 mm less if its length is over 2000, and the width is 1000 mm. In thickness for plates up to 50 mm, the difference is allowed ± 2 mm, and over 50 is allowed to make the difference ± 3.

If the length of the buyer is not suitable, then companies in the implementation of such products offer individual cutting. Length and width are important for transportation of building materials from the manufacturer to the customer. The main role is given to the thickness of the material.

GOST and its requirements for the size of polystyrene foam

The conditional designation of the GOST plates consists of letters and numbers in which:

1. Type of plate.
2. Brand.
3. Leaf dimensions.
4. Standard designation.

If the sheet has such characteristics as a plate of foamed polystyrene with the addition of brand 15 antipyrin, a length of 1200 mm, a width of 600 mm and a thickness of 40 mm, the record will look like this: PSB-C-15-1200x600x40 GOST 15588-86.

If the plate from the foamed polystyrene does not contain the flame retardant and refer to the brand 15, and its dimensions will be the same, the record will change and will look like this: PSB-15-1200x600x40 GOST 15588-86.

Using the technical requirements for the State Standard, the foaming polystyrene containing the pore formator: isopentane or pentane is used for the manufacture of foam plates. In total, the residual monomer styrene is added.

On the surface of the manufactured plates, ready for sale, there should be no bulges and a width of more than 3 mm wide and a height of more than 5 mm. Rivered ribs and angles can be observed, but not more than 10 mm from the vertex of the straight angle. The side of the dull angles may have no spaces for no more than 80 mm. All sheets of polystyrene are proper geometric shape. The deviation from the plane of the face is allowed not more than 3 mm for every 500 mm of its length.

The difference in diagonals for plates up to 1000 mm long should not exceed 5 mm, from 1000 to 2000 mm - no more than 7 mm is allowed, from 2000 mm - no more than 13 mm.

When accepting the party, linear dimensions are always checked, the correctness of the geometric shape, the appearance.

The consumer can be sure that in the party purchased by him all products will have the same dimensions.

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How to transport expanded polystyrene

Sliced \u200b\u200band finished foam polystyrene is packaged by the manufacturer in transport packages and is transported. GOST allows the transportation in an unpacked form if there is a guarantee that the sheets will not harm on the road. When forming a package, the requirements of GOST 21929-76 must be respected. The height of the formed packet should not be more than 0.9 m. With a plate thickness of 500 mm, the package is formed from two plates.

On the lateral facet of the product or package should be a marking containing a stamp of the enterprise, which made this product, type and brand of the plate.

Marking should be made according to GOST 14192-77 and contain the name of the enterprise or its trademark, the date of manufacture of products, its name and number of the party. It is indicated by the brand and type of plates, their number in the package.

There must be a standard designation, on the basis of which these products were manufactured.

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Foam stamps and sheet size

For insulation, several major foam brands are used. Each brand is characterized by its density, which is expressed in kg / m³. The higher, the lower its specific thermal conductivity and higher strength. The most common brand of the PSB foam plate sheet. Marking numbers indicate the density. So, PSB-C 15, standing at the very bottom of the density table, has only 15 kg / m³. It is the easiest, it is used to insulate the temporary residence of people: cabins, cars, as well as containers for heat conservation. This brand is used for insulation in warm areas with soft winters. It sends the walls to reduce sound insulation of interior partitions.

The brand of foam of PSB-C 25 with a density of 25 kg / m³ is greater popularity. Sheets of polystyrene foam of this brand having different sizes are used to insulate buildings, structures, buildings. Polyfoam is packed to improve the quality of thermal insulation and sound insulation of the wall, roof, floors, facade insulation.

The polystyrene was used for the manufacture of panels, reinforced concrete structures that are used in frame houses.

Sandwich panels and reinforced concrete structures, which are created by a non-removable formwork, contain in its design polystyrene foam of the PSB-C 35 with a density of 35 kg / m³. Such products in addition to their basic functions perfectly provide waterproofing walls.

PSB-C 50 with a density of 50 kg / m³ is used to arrange the floor of the refrigeration warehouses heated soils, in the construction of roads.

Extruded polystyrene foam and foam - one of the most popular thermal insulation materials, among the products presented in the market. These insulation seemingly, with a different price, possess similar technical characteristics, and choose the option suitable for use is sometimes very difficult.

In this article, we will deal with that better - foam or polystyrene foam, and what is the essential difference between these materials. A comparison of their technical characteristics and operational properties will be compared.

1 Features of Materials

Many people are often wondering than such a difference in price between these two materials is justified if they are most identical to each other.

The problem is that at least the foam is sometimes called polystyrene foam, since it is also manufactured by the method foaming from the same raw material - polystyrene, identifying extruded polystyrene foam and foam cannot be identical, as they have significant differences.

Differences of these materials are caused by different production technology. The transformation of the initial polystyrene raw materials into the foam is performed by exposure to a polystyrene steam by a high temperature, in which foaming of raw materials occurs during which polystyrene molecules are increased in size and connected with each other.

Extruded expanded polystyrene is manufactured by a completely different technology. Polystyrene raw materials in the production process is loaded into special equipment - an extruder, where heats up to the full loss of polystyrene molecules, resulting in a homogeneous liquid melt.

Next, the melt with a viscous consistency is passed under pressure through the extrusion head (the hole of the specified form), as a result of which the product is formed from the melt, which has a homogeneous structure.

Extruded polystyrene foam TechnoNIKOL (and we recommend) - these are monolithic interconnected molecules of foamed polystyrene, representing a single structure, through which no pairs, nor moisture penetrate, while polystyrene polymer molecules are simply connected to the polystyrene.

The production technology of extruded expanded polystyrene is different from the production of foam production technology much more complexness and the duration of the process, which causes the difference in price between these two materials.

The above differences in production technology determine the essential difference between the functional properties of these two materials. Consider them in more detail.

1.1 Heat conductivity

The thermal conductivity is the main characteristic of any heat-insulating material than the thermal conductivity is less - the so-effective is the insulation, and the smaller material thickness is required for high-quality insulation.

The thermal conductivity of extruded expanded polystyrene is 0.028 W / MK, the thermal conductivity of the foam - 0.039 W / MK. If he is not defective. To minimize the risk of acquiring defective goods, we recommend.

According to this characteristic, the extruded polystyrene foam is better as a foam and most of the insulation in the market in general.

1.2 Mechanical strength

As already mentioned, the structure of extruded polystyrene foam is monolithic, while the components of the foam are simply connected by each other.

This causes a serious difference in the strength characteristics of the materials under consideration. The extruded polystyrene foam is resistant to bending in the range of 0.4-1 MPa, and compressive strength 0.25-0.5 MPa, whereas the polyfoam has the data indicators within 0.07-0.2 MPa and 0.05-0.2 MPa, respectively.

In practice, with serious mechanical loads, crumble into small balls, of which it consists. Also, this material is very brittle, since it is sensitive to bending deformations.

The extruded polystyrene foam is able to withstand sufficiently serious bearing loads, due to the deformation of the building, as a result of shrinkage, or seasonal temperature changes.

The density of extruded polystyoline, as a rule, varies in the range from 30 to 45 kg / m3, while the actual density of foam is 15-35 kg.

According to the requirements of the quality standards of the Russian Federation, the actual density of foam can differ from the rated density by 10 kg / m3, as a result of which the real density of the same PSB foam-C35 rarely exceeds 26 kg / m3.

1.3 hydrophobicity

The ability to absorb water is an important characteristic of any thermal insulation material.

In high-quality insulation, this property must be minimized, since, with a set of moisture, the insulation is inclined to the loss of its thermal insulation characteristics, an increase in weight and, with a constant stay in a humid environment - rotting and destruction.

The extruded expanded polystyrene has a structure from closed cells, as a result of which the material has almost zero moisture absorption. If he is not deflected. Therefore, we recommend to avoid marriage.

With full immersion in water for 24 hours, extruded polystyoline absorbs liquids of no more than 0.2% of its volume, while this indicator does not actually increase with a longer stay of the material in water - when immersed for 30 days, polystyrene foam absorbs 0.4% of the volume.

In view of the structural differences, the polyfoam, this indicator is much worse - for 24 hours the material, with full immersion, absorbs 2% of the volume, during immersion for 30 days - 4%.

Such a difference in the indicators is more than significant, especially if the insulation will be used in the conditions complex in terms of humidity. When insulating the ground floor, foundation and facade, extruded polystyrene foam exploits itself much better.

1.4 Fireproof

The combustion consumption class of thermal insulation materials is becoming serious when it is necessary to carry out the insulation of objects, the design of which has multiple wooden elements - attic or roof.

Construction standards and rules are also prohibited from carrying out the inner heat insulation of industrial premises with combustible materials, as this contradicts fire safety requirements.

By the clamping class, the extruded expanded polystyrene was not different from the foam. All polystyrene-based products relate to combustibility groups (depending on impurities contained in the composition):

• G2 (normally combustible), as;
• G3 (strongly combustible materials).

To solve this issue, manufacturers, both in foam and extruded polystyrene foam, is added to the flame retardant - a substance, due to which the insulation acquires the ability to self-effect.

Research suggests that with a sufficient concentration of anti-epire, in the absence of direct contact with fire, these materials are fucked for four seconds.

1.5 leaning to shrinkage

Shrinkage, like moisture absorption, is the main enemy of any insulation. When the material shrinkage in the construction of the heat insulation appears slots, which significantly reduce the overall effectiveness of insulation.

One of the main problems of foam is the propensity to the shrinkage when heated. To greater extent, the deformation is manifested when the product is heated, according to this, the foam is better not to use for thermal insulation of the heap systems, and when insulating the foam of the facade, the insulation must be covered with white plaster protecting from UV rays.

With extruded polystyrene foam, things are much better, the material practically does not give a shrinkage in any operating conditions.

2 Conclusions

Considering all the above comparisons, the answer to the question: "What is better, the foam or polystyrene foam" is quite obvious, the effectiveness of thermal insulation by extruded polystyrene foam is an order of magnitude higher than almost all parameters.

To make sure that fully compare the main technical characteristics of these materials:

• Thermal conductivity, W / MK: expanded polystyrene - 0.028; Polyfoam - 0.039, like;
• Parry permeability coefficient, mg / MCPA: expanded polystyrene - 0.05; Polyfoam - 0.022;
• Material density, kg / m3: expanded polystyrene - 30-45, foam - 15-35;
• The percentage of moisture absorption from the volume when diving for 24 hours: expanded polystyrene - 0.2; Foam - 2;
• The percentage of moisture absorption on the volume when immersed for 30 days: expanded polystyrene - 0.4; Polyfoam - 4;
• Static bend resistance, MPa: expanded polystyrene - 0.4-1; Polyfoam - 0.07-0.2;
• Resistance to compression (during deformation by 10%), MPa: expanded polystyrene - 0.025-0.5; Polyfoam - 0.05-0.2;
• Class of flammability: polystyrene foam - r2, polyfoam g2 (normally combustible).

The range of permissible operating temperatures for both materials is from -50 to +75 degrees. When the temperature is exceeded above said, the deformation of the material begins. The ignition temperature of the extruded polystyrene was 450 degrees, foam - 310 degrees.

If you choose what to use for insulation at home, foam or polystyrene foam, then in case the last option fits into your budget, it is better to pay preference to it.

Extruded expanded polystyrene was a great option for thermal insulation of facades, foundations, floors, roofs and ceiling. In a house insulated with polystyrene foam, it will be for magnitude warmer than in a house, insulated foam. Best or.

If your finances are limited, then use foam, it certainly does not reach the technical characteristics to the estruted polystyrene foam, however, among inexpensive insulation, this is the best choice.

2.1 Overview of the features of extruded polystyrene foam (video)

The heat-insulating material is polystyrene foam, in use commonly called foam, today has found the widespread distribution in the construction and repair of residential and economic premises.

Compared to other insulation, these various types of polystyrene foam have a number of significant advantages, although they are inherent in some disadvantages. Polystyrene manufacturing technology involves foaming polymer - polystyrene gaseous pentane - low-boiling liquid from a group of hydrocarbons.

If we consider the structure of the foam, the proportion of the solid in its volume does not exceed 2.0%, and 98.0% are emptiness representing miniature polystyrene chambers, inside of which air is enclosed.

The nearest "relative" of this classic foam is the Penoplex, which is obtained by means. Today, these materials are quite often confused.

Although both of them have approximately the same physico-mechanical characteristics and equal thermal insulation indicators, Penoplex, despite its higher cost, in some cases it is preferable to use.

Main types of foam polystyrene

Polystyrene URSA XPS.

The production of polystyrene foam on an industrial scale was mastered in Germany in 1937. In the Soviet Union, the production of foam (Mark "PS-1") began in 1939, and since 1959, the production of self-fighting foamed polystyrene began at the Stroymplastmass plant (Mytishchi city).

Today, in the construction and repair and construction industry, the most widely used the following mediations and stamps of this material:

1. PESSION FIGHT "PSB" ("EPS" - "EXPANDED POLYSTIRENE") is the most common material - used for packaging and as a heat insulating material.
2. The foamed, suspension polystyrene "PSB-C" was patented by the BASF concern in 1951 and is currently the most widely used insulation.
3. Extrusion polystyrene foam ("XPS" - "Extruded Polystyrene") is known in the Russian market for building materials under the names of URSA XPS "Penopeleks", "Stireks", "Technonikol" and "Technoplex".
4. Foams produced by the American company "Dow Chemical Company" on autoclave and autoclastic-extrusion technology are known under the general name "Styrofoam".

Properties and dignity of material

PSB-C-15/25/35 foam

The physico-mechanical characteristics of foamed polystyrene depend not only on the manufacturing technology, but also from the manufacturer (trading brand) and the brand of the finished product.

The most propagated foam of the brand "PSB-C-15 / 25/5" has the following main characteristics:

1. Density in kilograms in a cubic meter (specific weight in kilonutytones in a cubic meter) - 11-35 (107.8-345).
2. The limit of flexural strength in megapascals - 0.05-0.17.
3. Compressive strength in megapascals (at 10.0% of linear deformation) - 0.05-0.16.
4. Material moisture in the delivery state does not exceed 1.0%.
5. Water absorption not more than 1.0% in 24.0 hours with direct contact with water.
6. The combustion time in the outdoor does not exceed 3.0 seconds.
7. The coefficient of thermal conductivity at ambient temperature + 25 ± 5 ° C was in the range of 0.033-0.037.

However, these purely technical indicators inform the usual user who are mainly interested in consumer properties of products.

The material has a certain airtightness and practically does not adsorb the atmospheric moisture.

The main advantages of any kinds and brands of polystyrene foam builders and users consider:

1. Low mass (weight) characteristics, due to which the timing of thermal insulating work is reduced, does not require the use of special lifting mechanisms, and insulated structures do not need additional insulation.
2. Polyfoam is suitable for any processing of processing that does not require complex equipment, and does not release any harmful to health, volatile substances during sawing and cutting.
3. Any type of foamed polystyrene is not subject to rotting, it is not a nutrient medium for the development of mold fungi, it does not damage rodents.
4. The material is chemically inert and resistant to the action of cement-concrete-lime solutions, seawater, most chemical reagents used in construction
5. All types of foamed expanded polystyrene are safe from an ecological and sanitary and hygienic point of view - when working with it does not require the use of personal protective equipment
6. The relative strength of the material is evidenced by its flexural endurance and the tensile strength.
7. Polyfoam is not a fuel - indicators of fire safety indicate that in the open air, the combustion of the material is possible only with the direct effect on it from another source or in excess oxygen.

If comparing polystyrene foam with other materials, then the heat insulating capabilities of 3.0 centimeters of foam is adequate:

1. 64.0 centimeters.
2. 123.0 centimeters of monolithic concrete.
3. 11.3 centimeters of a wooden, pine array.

The use of foamed polystyrene

An important value, due to which the material has become so widespread, is its low cost.

The main use of polystyrene foam - Use it as insulation when carrying out construction and repair work. In addition, it is used as a heat insulator in some types of household and industrial equipment (refrigerators, thermofursors, containers), and also finds use in the package.

For the insulation of the outer and inner surfaces of the walls in an individual and low-rise house building, the most widespread foam of the "PSB-C" of various density was obtained. Due to the greater breathability, compared with the extrusion (extruded) foam plants "Penopeleks", "Stireks", "Technonikol", its use allows you to create more comfortable microclimate inside the residential premises.

However, it does not reduce its merits. Due to the low price and excellent thermal insulation properties, in Europe, about 80.0% of private housekeepings of various purposes have foam insulation.

Reading time ≈ 4 minutes

The polystyrene foam is the third part of all thermal insulation materials used in the world. It is made by sintering polystyrene granules obtained through foaming of low-foaming liquids from a special suspension. This add foaming components. In Russia, it is often precisely a polystyrene foam-called foam. But nevertheless, there is some difference between the concepts of polystyrene foam and foam plastic, they are not always interchangeable.

Responding to the question of what is polystyrene foam, it should be noted that this is a hard gas-filled material having a cellular structure. However, there are no species that do not have gases.

Varieties of expanded polystyrene foam

• prestrial polystyrene foam (PSB, PSB-C, EPS);
• extrusion polystyrene foam (Painoplex, Technoplex, Styrex);
• press polystyrene foam (PS-1, PS-4, as well as imported materials);
• autoclave and autoclastic extrusion (extremely imported materials).

Scope of application

It is the prestickable polystyrene foam called foam. The main direction of application of this material is thermal insulation, sound insulation. They insulate walls, floors, windows, balconies, etc. The popularity of such a method of insulation is economically justified. If you need to access the closed area, you can simply remove the fragment, and then re-install it for your previous place. Low cost allows you to use it in other areas. It is often used to protect against the freezers of sports fields and other objects. The specific scope of application depends on the brand.

Extrusion variety is needed for thermal insulation and sound insulation of walls, facades, roofs, partitions, foundations. This species has greater durability compared to the prestickable variety. This is due to production technology. The extrusion method involves the melting of the initial granules and the subsequent fill of the resulting mass in the form.

Press polystyrene foams are taken in the manufacture of refrigerators, thermos, vehicle bodies. It is indispensable in shipbuilding. Electrical insulation properties make it in demand in the electric industry.

From polystyrene make packaging for products (disposable dishes, containers for fruits and meat products), technical packaging. In the photo you can see an example of numerous options for such goods. He became an indispensable material for creating decorative elements.

Basic properties

The polystyrene foam should be taken only for arranging the middle layer of structures. It perfectly tolerates temperature jumps from -40 ° C to 80 ° C. It is not used with the insulation of saunas, pairs, heating mains. However, the properties of the material do not limit its use as a heater of buildings. Even with a long stay under the right rays, it will not start melting, will not lose the structure.

Do not worry about safety material. The polystyrene is styrene, a substance contained in many products. It has been officially confirmed by its safety, the styrene is recognized as non-barcrogenic, non-merged, therefore it is allowed from this material to make packaging for food. In containers made of polystyrene and donor organs, medical preparations are transported. Since it does not contact the inner space of the house, the oxidation is impossible, so the styrene is not allocated from the heat-insulating layer.

Polystyrene granules from which this material is obtained is the oil refining product. Therefore, this is a combustible material. It is referred to as a group of G3 ("NormalNogorchy"). Often, special antipirens are added to the slab, the action of which is based on a decrease in the ability to distribute fire. So some modern varieties of material can burn independently no longer than 2 seconds.

Technical characteristics of polystyrene foam

Among the technical characteristics of the material, its low thermal conductivity has a special significance - 0.032 - 0.050 W / m * C, these indicators are significantly lower than that of bricks or concrete.

The second most important characteristic is good moisture resistance. So that absorption is 3%, it takes about the day of the contact of water with the material. The playproof is also very low - 0.06 mg / m * h * pa. Extrusion varieties even below - 0.013 mg / (m * h * pa).

The advantages of polystyrene foam include its inability to become an acceptable environment for biological media. He is not afraid of fungi and mold.

In this article: the history of the opening of polystyrene; production technology; scope of expansion of polystyrene foam; Application in construction, GOSTS; properties and characteristics; Environmentally friendly, durability and fire safety - this insulation is so safe; that in reality means the term "self-fighting polystyrene foam"; How to choose expanded polystyrene

The cost of heating our homes during the cold times is very significant, and the increasing cost of energy increases these costs from year to year. Do you know that in the cold the heat is literally disappearing from your home, and the loss of heat is not just great - they are colossal! Today, most of the buildings in Russia, not protected by insulating materials, loses about 600 heat gigacloories from each square meter, while from a square meter of housing in Germany or in the US takes only 40 gigacalories. It turns out that homeowners actually pay the heating of the street, and not at all their homes ... Solve the heat loss of the heat loss can insulation of the walls of the building from the outside by plates of polystyrene foam - but is it just just with this thermal insulator?

History of polystyrene foam

It all started in 1839, when the German pharmacist Edward Simon, experimenting with styrax (resin Liquidambar Orientalis), accidentally received styrene. Slightly experimenting with their discovery, the pharmacist established that the oily substance obtained themselves is applied independently, turning into a similarity of jelly. The practical purpose in the opening of Stirol Simon did not see - called the jelly styrene styrenexide and stopped further research.

In 1845, Stirol was interested in Chemists of the Physics and the background of Hoffmann - the Englishman and German conducted their own studies, establishing that this substance becomes jelly without oxygen access. Chemists called them the chest-like styrene metastirol. After 21, the French chemist Marcelin Burtlo gave the exact name of the styrene seal process - polymerization.

Herman Staudinger, 1935

In the 20s of the last century, the German chemist, German Staudinger, an epocheal discovery was made - styrene heating causes a chain reaction, during which long chains of macromolecules are formed. It was the discovery of Staudinger led to the production of polymers and plastics, for which in 1953 he received the Nobel Prize.

The first synthesis of styrene was made by researchers of the American company "The Dow Chemical Company", the commercial production of polystyrene among the first to be launched by the company "BASF" - in 1930, its engineers developed the production technology of polymerized styrene. In 1949, the company received a patent for the production of polystyrene balls foamed by Pentan - the very idea of \u200b\u200bthis invention belongs to the Chemistry Engineer Fritz Shtyasny. Based on this patent in 1951, BASF begins industrial production of thermal insulator under the Styropor brand name, produced to this day.

The raw material for the production of all types of polystyrene isolation is the granulated polystyrene, for the formation of cells, the foaming agent is used. Stages in the technological process of producing polystyrene foaming several:

• polystyrene granules are falling asleep in the bunker of a precipitator, where they swell and acquire a spherical shape. To obtain a thermal insulator of a lower density, the foaming operation is repeated several times, with each time reaching an increasing size of the balls in order to reduce the actual weight of expanded polystyrene;
• each foaming operation is accompanied by placing foamed pellets into a special bunker, where bloated polystyrene balls are from 12 to 24 hours. During this period, the pressure inside them is stabilized, and during the production of suspension polymerization, their drying occurs;
• upon completion of the specified number of foaming operations and withstanding the period of sealing, polystyrene balls are placed in the molding unit, where a polystyrene foam unit is formed under the action of a hot steam. Pressed in a narrow mold, extended under the influence of steam foam granules glued together with each other, keeping the form after cooling and extracting from the mold;
• at the last stage, blocks of polystyrene foam, often having an impressive dimensions, are subject to cutting on specified sizes. But before the block from the molding unit is placed on intermediate storage, which contains about 24 hours. The fact is that under the influence of steam, the polystyrene foam unit is gaining an excessive moisture, and it will not work in a wet state of polystyrene, because Avoid donomov will not be able to avoid. After drying, the polystyrene foam unit is cut vertically or horizontally with machine saw.

The main methods of producing expanded polystyrene two are suspension polymerization and polarization in the mass. The technology of suspension polymerization is based on the inability of water to dissolve vinyl polymers. At the stage of foaming, the styrene granules fall asleep in autoclave reactors with a volume of up to 50 m 3, filled with demineralized water with the polymerization initiator dissolved in it and the emulsion stabilizer. Polymerization passes under constant pressure, with a uniform temperature rise from the initial 40 to the maximum 130 o C - on the whole process is given at about 14 hours. The foamed polymer is extracted from the reactor together with an aqueous suspension, separated from it in a centrifuge, then washed with water and passes the drying stage. The main advantages of this technology is the constant peeling of the polymer granules inside the reactor during the polymerization, the effective distribution and heat dissipation, which results in a significant storage period of the foamed polymer.

Polymerization technology in the mass is carried out otherwise - water is absent, the polymerization process is continuous and passes at higher temperatures. In a series of sequentially connected mixers of reactors, at temperatures from the initial 80 to the final 220 ° C, polystyrene granules foam. The polymerization is considered to be and completed if it is molten from 80 to 90% of the original styrene. When creating a vacuum in the last column type reactor, the styrene was not eliminated, the anti-epires, dyes, stabilizers and other additives are introduced into the melt, as a result of which the polymer granulation occurs. Non-reaction and extracted styrene is used for the next tab. Bring the process of polymerization of raw materials to getting over 90% of foamed polystyrene with this technology is extremely difficult, because The rate of reaction is high enough, and there is no possibility of heat removal here.

The production of foamed polystyrene according to the method of suspension polymerization is more common in Russia and the CIS, in the countries of the West and America, the polymerization technology prevails in the mass, which allows to obtain a heat insulator with higher characteristics on density, flexibility, clarity of borders and color, not to mention the smaller waste percentage.

The technology of obtaining extruded (extrusion) expanded polystyrene in general is similar to polymerization technology. The difference is to join the melt with the foaming agents entered into its composition through a press extruder, resulting in a heat insulator with cells with a diameter of up to 0.2 mm. It is the small cell size that provides extruded polystyrene foam, high operational properties and popularity in the construction industry.

Areas of use

The combination of strength and thermal insulation properties, ease of processing and processing, low cost - thanks to these characteristics, polystyrene foam is widely distributed in various spheres of our life. Most often, this material is used for: packaging of various goods and equipment; isothermal packaging of food; production of disposable dishes; energy emissions in the automotive industry; rescue swimming agents; bulk outdoor advertising, etc.

The lack of threat of dusting is the main positive difference of polystyrene foam from mineral wool, allows you to use this material for thermal insulation of refrigeration equipment in the food industry.

Polystyrene foam is used for thermal insulation of the road leaf, preventing the freezing of the base. For this purpose, high density polystyrene foam brands are used - from 35 kg / m 3 and higher. This material is used for thermal insulation of the railway canvas, effectively preventing the rails of the rail and their sediment on unstable soils.

One of the first to apply foam for insulation of buildings began the American Hut Heddd. According to him, the idea of \u200b\u200bthermal insulation of houses emerged by chance - Hut ordered a cup of hot coffee in a cafe and suddenly noticed that the hot liquid in a one-time cup of polystyrene does not burn his fingers at all. After spending an experiment in 1984 - building a house on Alaska and insulated with its foam - he was convinced of the effectiveness of the polystyrene heat insulator.

According to GOST 15588-86, it is permissible to use polystyrene foam as an insulating intermediate layer of building structures. In the countries of the European Union, polystyreneol for more than 40 years is successfully used in the facade insulation - the plates of polystyrene foam are pasted on the main structural material, be it concrete or brick, with an external (outer) side, they are covered with a layer of plaster.

According to European architects, the use of polystyrene foam in facade insulation reduces energy consumption for heating three times.

Plates and blocks of extruded polystyrene foam are used as a non-removable formwork and simultaneous heat insulator. The technology used is as follows: polystyrene foam plates are installed at a given distance from each other, they are connected to each other with a special system of screeds, the reinforcement reinforcement is laid between the slabs and concrete is poured. A variety of finished polystyrene blocks allows you to build facades of complex architecture. The walls filled out of the extruded polystyrene foam and filled with concrete walls are sure to apply a protective coating - outside it can be a facing brick or cement-sand plaster, from the inside two layers of drywall with docking "into the dispersion" or layer of plaster. An important condition for formwork from expanded polystyrene: the density of this material in the formwork blocks should be at least 35 kg / m 3.

Glue for expanded polystyrene should not contain in its composition organic solvents that destroy polystyrene. The most safe to use cement-based adhesives, packaged in kraft bags of 25 kg and laid water - the inorganic components of such mixtures will not be on a polystyrene no negative effect. Important moment: It is necessary to achieve the greatest contact area of \u200b\u200bthe plate of polystyrene foam with a warmed surface (ideally - 100% contact area) to eliminate the air sinuses acting as the bridges of cold and accumulating condensate.

Heat resistance

The high thermal insulation properties of polystyrene foaming are explained by its structure formed by the set of balls of the balls, in turn consisting of a variety of cells with air enclosed in them. And since the air inside the cells is not capable of moving, it is it that acts as thermal insulator - a fixed air environment has excellent insulating properties. In essence, polystyrene foam consists of air - 98% air and only 2% of the initial polystyrene.

The thermal conductivity coefficient of this material is lower than any other heat insulator, incl. Mineral wool, and is in the range of 0.028-0.034 W / m · k. The thermal conductivity of polystyrene foaming increases with increasing its density, for example, in extruded polystyrene foam with a density of 45 kg / m 3, the thermal conductivity coefficient is 0.030 W / m · k. Working temperatures in which expanded polystyrene retains its properties - from - 50 to +75 o C.

Water absorption and vapor permeability

If you compare the extruded polystyrene foam with a foam produced from the same styrene, but a few other technology, then the vapor permeability of the foam is zero, and the extruded polystyrene foam has vapor permeability in 0.019-0.015 mg / (m · h · par). The question arises: how is it possible, because the structure of any material from foamed polystyrene can not miss steam? The cause of vapor permeability is more dense compared to the foam of extrusion polystyrene foam - steam penetrates into the balls and the components of their cells along its parties, cut when forming, while the forming of foam products is performed without cutting. With water absorption, the situation is the opposite: the foam is capable of absorbing up to 4% of water during immersion or contact with it, and extruded polystyrene foam is only 0.4%, which is explained by its greater density.

Close-up structure of extruded polystyrene foam

Strength

For strength, the unconditional leader is extruded polystyrene foam - its static bending strength is 0.4 - 1.0 kgf / m 2, the foam is 0.07-0.20 kgf 2. The links between the extrusion polystyrene molecules are repeatedly stronger than in the structure of foam. Therefore, the production and use of the latter is increasingly declining - a more durable and modern thermal insulator comes to replace the foam, which is a polystyrene foam, obtained by plying through a press extruder.

Interaction with chemical and organic products

No exposure to exposure to polystyrene foam: construction solutions based on plaster, cement, anhydrite or lime; Bituminous resins, caustic soda, soap and salt solutions, mineral fertilizers, groundwater and emulsions used during asphalting. They damage, destroy the structure and completely dissolve polystyrene foam in some cases: olifa, some types of varnishes, organic solvents (turpentine, acetone, etc.), alcohol-containing compounds and petroleum products.

In addition, on the open surfaces of polystyrene foaming is the destructive effect of ultraviolet with sun rays - regularly irradiated surface loses elasticity and strength, after which the destruction of the polystyrene structure is atmospheric.

Soundwork

The use of polystyrene foam for sound insulation is effective only partially - with sufficient thickness, this material is great for protection against shock noise, but it is not capable of fighting air noise, whose sound waves apply to air. The inability of polystyrene foaming to extinguish the air noise is associated with the full insulation of the components of its cells and a significant rigidity of the external surfaces.

Biological stability

The life of mold on the surfaces of polystyrene foam slabs is not possible - these are the results of the 2004 laboratory tests conducted in the United States commissioned by American producers of expanded polystyrene.

Characteristics for fire safety, environmental friendliness and durability of polystyrene foam

Manufacturers of this thermal insulation material call it extremely environmentally friendly, non-combustible and maintenance properties for many years. Externally, it looks like that - the exclusion of freon from the technological process does not harm the ozone layer, the introduction of flames makes polystyrene foam not supporting combustion, and laboratory tests of dozens of freezing and thawing cycles are characterized by durability. However, the more close study of expanded polystyrene shows a slightly different picture ...

The oxidation of the air-based materials based on styrene is completely impossible, and the foaming rate is higher than that of extruded polystyrene foam - in the structure of foams, larger balls and less strong connections. The higher the temperature - the greater the oxidation rate, while the polystyrene is not required to burn, the separation of toluene, benzene, ethylbenzene, formaldehyde, acetophenone and methyl alcohol occurs during the air oxidation process at room temperature more than + per C. In addition, the freshly foam polystyrene highlights styrene not polymerized in the production process. I repeat - 100% the polymerization of all the raw materials laid into the reactor is impossible.

All types of polystyrene are combustible - from the point of view of the official system of classification of building materials, those of them that lose the initial volume when heated in airspace is combustible. The approval of the polystyrene manufacturers of any type of its independent attenuation does not reflect the fire characteristics of the polystyrene to the fullest, i.e. The information is intentionally distorted.

Most of the manufacturers of this thermal insulator claim that the heated expanded polystyrene is distinguished by no more poisonous substances than the tree. If combat poisoning substances are distinguished during the burning of the tree, then such a statement is true - after all, under the influence of heat over 80 o C, the polystyrene is distinguished by a large amount of smoke and soot in the air. Small amounts of hydrobromide (hydrogen bromide), hydrogenide (sinyl acid) and carbonyl dihloride (phosgene).

So what gives manufacturers of polystyrene foam to argue that their product is less dangerous during fire, than wood? According to Russian GOST 30244-94, this statement would be simply impossible, because this standard refers materials based on polystyrene foam, as the most combustible, to groups G3 and G4. But in Europe there is a different methodology for evaluating a flammability, or rather, their integer three are biological, chemical and complex. According to the biological methodology of the toxicity estimate, the most dangerous material is precisely wood materials - quickly burn with the release of a large amount of CO2 at temperatures of self-burning. But the assessment of the toxicity by the biological method is given only by several finite parameters, unpleasurable, for example, when comparing the toxicity of combustion products of wood and polystyrene. Similarly, things are the calculation of toxicity with the chemical method ...

The real picture gives only an integrated method, unconditionally used in Europe to all polymeric materials.

However, in Russia, Suppliers of European Polystyrene and Local Manufacturers demonstrate expert opinions only on biological and chemical methods, actively giving this data to the general public.

Another classic stroke, allegedly demonstrating polystyrene, is suspended in the air, the burner flames are sent to it - so part of the plate, where the open flame falls, burns, but then the fire does not apply. What conclusion can be given a polystyrene after watching this video? And no - if the same polystyrene plate is put on a rigid non-flammable surface, then the melt drops formed during the combustion of the material will be highlighted with high temperature and open flame across the entire area of \u200b\u200bthe plate, which grows completely!

The smoke coefficient for polystyrene foam not containing antipyrine is 1,048 m 2 / kg, but in self-pulling polystyrene foam with their antipirens entered into its composition, this figure is higher - 1 219 m 2 / kg! For comparison: coefficient of rubber smoke formation is 850 m 2 / kg, and wood with which manufacturers constantly compare polystyrene products - only 23 m 2 / kg. Since for not a specialist in fire safety issues, the lifting effects of smoke formation are not explained, I will give such data - if there is a smoothness in the room more than 500 m 2 / kg, then at the distance of the elongated hand will not be visible to an even account.

The consequences of the combustion of polystyrene are known in the 2009 tragedy, which occurred in Perm, in the nightclub "Chrome Horse" - most of those killed in this fire suffocked the products of the burning of the insulation, who were openly covered by the inner partitions. It should be noted that the club owners saved on the insulation, using non-extruded polystyrene foam, and the packaging foam of a smaller density that is superbly burning and is not inclined to self-filing.

Durability of polystyrene foam

When buying a really high-quality thermal insulation material, compliance with all requirements for installation, the full closure of the external area of \u200b\u200bexpanded polystyrene with a layer of high-quality plastering or decorative panels, its service life will be over 30 years. But these conditions actually never respected by 100% - non-professionalism of the installers, attempts by customers to reduce costs, errors in the calculations and hope "on Avos".

The classic miscalculation is the bid on the thickness of the polystyrene - they say, if they mount the plates of 30 cm thickness, the thermal insulation effect will increase at times with the simultaneous increase in the service life of the material. In fact, with increasing thickness, the service life of polystyrene heat insulation will be reduced, because Significant temperature differences will cause strain and shrinkage, forming cracks and a decrease in the area of \u200b\u200bdirect contact plates of polystyrene plates with an insulated surface, forming extensive air sinuses. In the European Union countries, the thickness of the polystyrene foam used for facade insulation cannot exceed 3.5 cm - this requirement, in addition to the durability of thermal insulation, is associated with fire safety, because the thinner of the polystyrene layer, the smaller of the combustion products will be highlighted by fire.

In order to reduce the threat of fire, manufacturers are injected into polystyrene antipyrenes, as a rule, it is hexabromotsicodekan. In Russia, polystyrene foam with antipirens in its composition is marked with a Literus "C", meaning "self-fighting".

By and large, self-fighting expanded polystyrene is burning no worse than the materials that do not contain the flames.

The question arises - so what does the letter "C" mean? And it means that this polystyrene is not self-splashing when the temperature is raised, nothing more. According to the degree of flammability, a self-fighting expanded polystyrene was assigned a class of G2, but it is worth considering that during the period of operation the flame retardant will gradually lose its properties, i.e. After a few years, the actual class of flammability of such polystyrene was not higher than g3-g4.

Criteria for the choice of polystyrene foam

Cheapness, high thermal insulation qualities made polystyrene-based materials extremely popular in the construction market. And the increase in demand led to the emergence of many enterprises, in line by offering products of their own production, claiming its exceptional quality.

Be careful by selecting the brand of polystyrene - as a facade insulation, it will be correct to choose the PSB-C (polystyrene of self-tapping) not lower than the 40th brand. It is worth considering the nuance - the manufacturer within the framework of the same-developed PSB-C-40 density in the range from 28 to 40 kg / m 3, and not 40 kg / m 3, as an unfinished buyer implies, focusing on the figure in Mark . It is quite natural that the manufacturer is more profitable to produce a brand 40 with the smallest density, because it earns more, spending less on the feedstock. The stamps of polystyrene foam below the 25th use in construction is meaningless - the density of such polystyrene will actually correspond to the packaging foam, unsuitable for facade insulation due to the rapid loss of operational qualities.

It would be nice to find out what the technological process of obtaining expanded polystyrene is applied at the enterprise of this manufacturer. If an enterprise produces polystyrene foam density of more than 35 kg / m 3, then it must be an extrusion method, because Without compressing during the production process, the largest polystyrene density will not exceed 17 kg / m 3.

You can find out the quality of polystyrene by having doubtted it - the low density material (used only for packaging) will be reduced between the balls, their shape in the place of don is a rounded, the size is different. The dome of the high-quality extrusion polybedyrol will show the forming polyhedra of the same size, the dymna line will partially pass through them.

The correct decision will be the acquisition of polystyrene foam of the well-known manufacturers of Europe "BASF", "Nova Chemicals", "Styrochem", "Polimeri Europa" or domestic "technonikol", "Penopeleks". Production capacity of these manufacturers of polystyrene foams is sufficient for the release of a really high-quality product.

In completion

In the presence of negative characteristics of combustibility and combustion products, polystyrene foam is one of the best and, at the same time, inexpensive thermal insulators. Conding the polystyrene plate between the two layers of cement plaster, it is possible to obtain high-quality thermal insulation of buildings and premises - to deny this fact is meaningless. In Europe, about 80% of public and residential buildings are insulated by the facade of precisely polystyrene foam.

Polystyrene foam as a construction insulation, a full-fledged test of time has not yet passed - from the moment of the first application no more than 40 years passed.

Widely distributed information information on unchanged quality for 80 years of operation is based on laboratory tests, which can be influenced by - say, providing a special batch of samples to analyze.

When insulating polystyrene foam of the facades is extremely important to completely protect the outer surface of this thermal insulator with a sufficient layer of plaster on the cement binder - the slightest area of \u200b\u200bthe contact of polystyrene foam with the atmosphere and the solar ultraviolet will result in its rapid destruction.

Is it worth it to insulate this material inner premises - not worth it, despite all the assurances of manufacturers. They will give guarantees, but what will be all this will be in case of fire ...

Abdjuzhanov Rustam, RMNT.ru