Real-Time Monitoring During the Production of Expandable Polystyrene

Polystyrene is a widely used, low-cost plastic and highly versatile. It comes in solid and foamed form. Foamed polystyrene has lower mechanical strength compared to solid polystyrene but also very low thermal conductivity. Depending on the type of production, a distinction is made between fine-pored extruded polystyrene (XPS) and the more coarse-pored expanded polystyrene (EPS), which characteristically consists of small plastic beads that are fused together. Due to its technical properties such as low weight, stiffness and formability, expanded polystyrene can be used in a variety of applications, for example as a shock-absorbing packaging material or for thermal insulation for buildings. During the production process of expandable polystyrene beads, continuous monitoring of the polymerization reaction is essential for the Italian chemical manufacturer »Versalis S.p.A« in order to obtain a high-quality product and high yield and to ensure optimal control of the production line. Important parameters that must be controlled during the suspension polymerization of EPS are the measurement of the polymer particles that form and grow during the reaction, as well as the degree of conversion of the styrene monomer into the polymer.