VALCO GROUP to discover the process of Polyurethane manufacturing
Polyurethanes, also known as polycarbamates, are some of the most versatile polymers. First developed in late 1930s, they are used in building insulation, surface coatings, adhesives, and solid plastics. Polyurethanes can be produced in four different forms including elastomers, coatings, flexible foams, and cross-linked foams. Each one has specific uses based on theirs properties.
Polyurethanes are produced by reacting an isocyanate and apolyol of various types (most common isocyanates: TDI (toluenediisocyanate) and MDI (methylenebisdiphenyldiisocyanate); mostcommon polyols: PTMEG (polyetetramethylene ether glycol), PPG (polypropylene ether glycol)).
During the process of Polyurethane manufacturing, the raw materials are pumped from their own storage tank to a common mixing vessel kept under controlled pressure and temperature. Here, additives are incorporated in accordance with a specific recipe. The temperature control inside the reacting vessels is usually made by a recirculating system such as the one illustrated in figure 1.
Polyurethane foam is the most widely used flexible foam plastic. It is produced by adding a blowing agent such as carbon dioxide and methylene chloride. Hard polyurethane plastic can be formed if the polymerization reaction is carried out without blowing agent. In some applications, continuous systems are a good alternative to the batch polyurethane production process, as it can reduce the risk of failed batches.