Production of polyurethane foam: technology, raw materials, equipment

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

Mounting 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. The variety of applications of this product also determines the need for a differentiated approach to the technologies of its manufacture. However, the differences in foam production methods are more of a cosmetic nature, without affecting the basic technological processes.

Product production technology

The chemical process of manufacturing polyurethane foam is implemented in three stages:

• Preparation of basic raw materials.
• Creating an active mix for making foam.
• Modification of the prepared base to provide the necessary physical and chemical performance.

Already issued in a separate orderaerosol cans and other containers for commercial foam content. For injection, a separate technological stage is also organized as part of the general production of polyurethane foam using specialized equipment.

An important condition of the production process is the control of the foam mixture polymerization process. At the main manufacturing stages, it is required that the foam acquire 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, which 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 manufacturers buy this raw material and use it to prepare mixtures according to their own recipes. What ingredients form the production raw materials? The main and most common elements are polyesters, propellants, isocyanates, polyols and polyisocyanate with various chemical additives. For example, to accelerate certain reactions between different groups of components, catalysts can be added. In general, the number of components of the polyester composition can reach ten, taking into account the components that stabilize chemical production processes.

Production equipment

Typicalconveyor line for the production 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 sealer. Equips cylinders with foam dispensers.
• Pump. Installations on servomotors that ensure the movement of the mixture along the technological delivery channels.
• Rotary 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 same technological procedure, perform the tasks of filling and rolling aerosol cans.

In addition, modern production facilities are widely equipped with measuring instruments to control technical operations and the state of the mixture. For example, the basic set of such devices includes micrometers, pressure gauges, level gauges and thermometers.

Composition of polyurethane foam

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 markings "A" and "B" has already been formed. The first group is formed by a hydroxyl-containing liquid, which, when combined with components "B", creates an active polyurethane foambasis. It is also important to note the proximity of the chemical mixture to the gas component, which also fills part of the aerosol can. Propylene is used as a pushing component - it is a colorless gas that is obtained as a result of oil refining by the pyrolysis method. In spray cans, it is usually located closer to the neck, but the correct position is that in which the active mass is on top. For this reason, it is advisable to turn the can upside down before opening the valve.

Performance properties of polyurethane foam

Polyester blend knowingly goes through several technological stages with processing and modification. Careful preparation of mounting foam in production gives it the following performance:

• Sealing capacity.
• Heat insulation.
• High adhesive power (stickiness).
• Mechanical strength.
• Ensure noise reduction effect.
• Machining pliability.

If we talk about the weak points of mounting foam, then the opinion about this product as unsafe from an environmental point of view has long been formed. Are such fears justified? It should be noted that a modern person has been faced with different forms and types of polyurethane foam since childhood. However, this applies to cured materials and substances. And the same goes for hardened foam, which is not harmful. However, when melted in direct sunlight or under artificial heating conditions, the foam may release unwantedtoxic substances.

Large manufacturers of polyurethane foam

Foreign companies set trends in this segment, demonstrating unsurpassed product quality. The Belgian company Soudal and the German Kim Tec can be attributed to the leaders of the world production of polyurethane foam products. Both manufacturers produce high-quality foam specifically for construction and installation work. In the domestic sector, first of all, it is worth noting the Tula manufacturer Profflex. Under this brand, a wide range of household and professional compounds is produced, focused on the tasks of sealing, sealing, sealing, etc. In addition, it makes sense to refer to the products of the Russian brands DeLuxe, VladPromPen, Premium Product, etc.

Conclusion

Mounting foam is a rather specific tool that requires the user to have at least basic knowledge about the features of its application. Although the modern production of polyurethane foam is increasingly focused on facilitating the process of its technical application, the very mechanics of the action of polyurethane foam imposes a number of requirements in terms of installation organization. This also applies to the setting time, and contacts with other materials, not to mention the possibility of expanding the already hardened foam under the influence of high temperatures. But, despite the operational subtleties and nuances, polyurethane foam continues to be a valuable assistant for both professional builders and ordinary home craftsmen.