Foam from the usual means of sealing window openings has long passed into the status of a full-fledged building material, which is widely used in a variety of types of work. A variety of areas of application of this product determines the need for a differentiated approach to the technology of its manufacture. However, differences in the production methods of polyurethane foam are more cosmetic in nature, without affecting the basic technological processes.
Product manufacturing technology
The chemical process for the manufacture of foam is implemented in three stages:
- Preparation of basic raw materials.
- Creating an active mixture for the manufacture of foam.
- Modification of the prepared framework in order to ensure the necessary physical and chemical performance.
Already in a separate order, aerosol cans and other containers for marketable foam content are produced. A separate technological stage is also organized for injection as part of the overall production of polyurethane foam using specialized equipment.
An important condition for the production process is the control of the polymerization of the foam mixture. At the main stages of manufacturing, it is required that the foam obtains the desired structure with a sufficient margin of rigidity and elasticity. To support certain properties and characteristics, special modifiers and plasticizers can be added to the mixture to increase the special qualities of the material, such as fire resistance or moisture resistance.
Raw materials for production
In a broad sense, the raw material base for the manufacture of polyurethane foam refers to a polyester composition, the components of which are produced by chemical plants under special conditions. Foam producers buy this raw material and, on its basis, prepare mixtures according to their own recipes. What ingredients form the manufacturing raw material? The main and most common elements include polyesters, propellants, isocyanates, polyols and polyisocyanates with various chemical additives. For example, to accelerate certain reactions between different groups of components, additional catalysts may be added. In general, the number of constituents of the polyester composition can reach ten, taking into account the components that stabilize chemical production processes.
Production equipment
A typical conveyor line for the manufacture of polyurethane foam contains the following functional modules:
- Semi-automatic dispenser. Provides targeted delivery of mixtures to other functional organs and devices, including cylinders. The average dosage varies from 250 to 450 ml.
- Valve Roller. Equips cylinders with foam dispensers.
- Pump. Installations on servomotors that ensure the movement of the mixture through technological delivery channels.
- Rotation module. Universal unit for filling containers with liquid mixture and propellant gas. This unit is close to automatic equipment for the production of polyurethane foam with conveyors, which, within the framework of one technological procedure, perform the tasks of filling and rolling aerosol cans.
In addition, modern plants are widely equipped with measuring instruments for monitoring technical operations and the state of the mixture. For example, the basic set of such devices includes micrometers, manometers, level gauges and thermometers.
Foam composition
In the composition, you can find a slightly different set of ingredients than the composition of the chemical raw materials from which the polyester composition was formed. This is due to the basic stages of processing and production modification, as a result of which a special group of components with the markings “A” and “B” has already been formed. The first group is formed by a hydroxyl-containing liquid, which, when combined with components “B”, forms an active polyurethane foam base. It is important to note the proximity of the chemical mixture with the gas component, which also fills part of the aerosol can. Propylene is used as the buoyant component - it is a colorless gas, which is obtained as a result of oil processing by the pyrolysis method. In cans, it is usually located closer to the neck, however, the correct position is where the active mass is on top. For this reason, it is advisable to invert the can before opening the valve.
Operational properties of polyurethane foam
The polyester mixture is not in vain passes through several technological stages with processing and modification. Careful preparation of polyurethane foam at the production endows it with the following operational qualities:
- Sealing ability.
- Thermal insulation.
- High adhesive ability (adhesion).
- Mechanical strength.
- Providing noise reduction effect.
- Compliance in processing.
If we talk about the weaknesses of polyurethane foam, then an opinion has long been formed about this product as unsafe from an environmental point of view. Are such concerns true? It should be noted that modern people have been confronted with different forms and types of polyurethane foam since childhood. However, this applies to cured materials and substances. And the same goes for frozen foam, which is harmless. However, in molten form under direct sunlight or under conditions of artificial heating, the foam may release unwanted toxic substances.
Large manufacturers of polyurethane foam
Foreign companies set trends in this segment, demonstrating unsurpassed product quality. The leading manufacturers of global production of polyurethane foams include the Belgian company Soudal and the German Kim Tec. Both manufacturers produce high-quality foam specifically for construction and installation works. In the domestic sector, it is first of all worth noting the Tula manufacturer Profflex. Under this brand, a wide range of household and professional compounds is issued, focused on the tasks of sealing, sealing, sealing, etc. In addition, it makes sense to turn to products of Russian brands “DeLux”, “VladPromPen”, “Premium Product”, etc.
Conclusion
Foam is quite a specific tool, requiring the user at least basic knowledge about the features of its application. Although the modern production of polyurethane foam increasingly focuses on facilitating the process of its technical application, the mechanics of the action of polyurethane foam imposes a number of requirements from the point of view of organization of installation. This applies to the setting time, and contacts with other materials, not to mention the possibilities of expanding the already frozen foam under the influence of high temperatures. But, despite the operational subtleties and nuances, polyurethane foam continues to be a valuable assistant to both professional builders and ordinary home craftsmen.