Factors Effecting Bulk Density of Expandable Polystyrene on Pre-expansion Process

Abstract

The expandable polystyrene is a light weight material which has been widely used in constructions, packaging and Marines devices. The manufacturing of the expanded polystyrene products is a multi-step process that depends on extremely high mutually correlated factors. EPS density is considered to the main index in most of its properties. Most mechanical properties depend on the density of EPS. The cost of manufacturing an EPS block is considered linearly proportional to its density. Non -mechanical properties like insulation coefficients are also density dependent. In this reach the pre-expansion process was studied to determine the effect of the expansion pressure, expansion time and size of bead on EPS bulk density. Analysis of test results confirmed that with increasing of beads size the bulk density of EPS decreases. Study showed that with increasing pressure the bulk density of EPS decreases. And with increase the expansion time the density decrease .Through the appropriate choice of time and pressure during the expansion process a wide range of density of EPS can be obtained.