Expanded polystyrene granules are becoming increasingly popular in the construction industry. They are not inferior in their characteristics to other types of insulation, while being notable for their low cost and environmental friendliness. Their size can vary from 2 to 8 mm. Granules have a dense structure filled with air, so that they acquire a low level of thermal conductivity and water absorption.
Varieties
There are two types of material:
- Primary polystyrene foam. All elements have identical parameters and are implemented in various modifications, for example, Mark-50 and Mark-15, each of which has certain mechanical and physical indicators.
- Secondary. It is a by-product obtained in the manufacture of foam. Expanded polystyrene granules have an irregular shape, but their properties are not inferior to the first type.
Use cases
The material has gained wide distribution and is used as:
- bulk filling in packaging boxes;
- fundamentals for filters in water treatment systems ;
- filler for soft toys, furniture, pillows;
- insulation for wall structures, floors and floors;
- heat-saving and sound-insulating layer in building envelopes;
- decorative means (creation of crafts and interior elements);
- filling for pontoons.
Expanded polystyrene foam granules act as one of the main components in the preparation of expanded polystyrene concrete, which is optimally suited for the insulation of floors, roofs and floors. To make a solid solution, it is necessary to combine polystyrene itself, cement and water in a concrete mixer. Before laying the composition, it is necessary to thoroughly clean the surface. In the process of work, the speed of action has a special role, since the solution solidifies almost immediately. Installation of reinforcing nets is carried out if the working surface exceeds the mark of 50 mm or is made of waterproof material, profiled flooring, linoleum of any kind and wood. If the surface thickness is less than 5 cm, then reinforcement becomes optional. During installation, the ambient temperature must be at least 5 degrees.
Advantages
Expanded polystyrene foam granules have many positive aspects, among which the following should be noted:
- invariable form;
- environmental Safety;
- ease of use;
- low cost;
- minimum weight;
- the ability to use for various design decisions;
- resistance to frost and fire;
- extensive scope;
- high level of heat and sound insulation.
How is polystyrene foam made?
Granules, the price of which starts at 1600 rubles per cubic meter, are produced as follows:
- Repeated or single foaming. Elements are supplied to the pre-foamer, in which their structure expands and gets a round shape. The process can be performed several times in a row, until the desired density level is obtained.
- Curing is necessary to form a stable pressure in the internal cavity of the elements. It takes at least 12 hours to dry.
The foaming stage has two stages, while its passage time is selected for each individual batch, depending on the quality of the material. Of particular importance is the observance of all the rules, since when the required time is exceeded, the structure begins to collapse. As mentioned earlier, polystyrene granules enter the pre-foaming agent, which is a reservoir with holes for supplying steam and a device for mixing the raw materials. In the process of foaming, the temperature reaches 110 degrees. At this time, pentane under the influence of hot steam contributes to the expansion and softening of the material, the total volume increases by 40-50 times, while the structure remains the same.
To accelerate this process, mechanical stirring is used. Then the cells rise under the influence of high pressure and pass into the intermediate tank, from which they are fed into the container for drying.
Features
Foamed raw materials contain approximately 10% moisture. Due to the fact that the condensation of steam and pentane causes a vacuum in the internal cavity, there is a possibility of compression of the material, due to which the thermal insulation characteristics decrease and the total volume decreases. That is why aging is an integral stage of production. This stage provides the normalization of pressure inside the cells and the strengthening of the outer surface.
The necessary resistance properties are achieved by exposure to a warm stream of air penetrating the cells. Moreover, with a decrease in the degree of density, the rate of absorption of air increases.
Expanded polystyrene granules dry out within 5-10 minutes. This process can be combined with material transportation. Curing provides not only the required level of humidity, but also an increase in the fluidity of polystyrene.