Simple Introduction to the EPS Raw Material
The expandable polystyrene is a small granular resin and generally has a diameter of 0.01 to 0.1 in. Most of such particles are beads produced by suspension polymerization, while larger diameter particles are also obtained by pelletizing. The size of the beads used is determined by the minimum wall thickness of the final foam product. It is easier to make larger particles to make low-density foam products, and smaller particles are easier to make into evenly filled parts.
The properties of a foamed plastic product depend on the base polymer, but are greatly affected by the density of the foam. A 97% by volume foam foam product with a density of 11b/ft3 is air, which has poor mechanical properties. The air contained in the foam is divided into millions of cells, and their presence gives the polymer foam a number of valuable properties. These characteristics include thermal insulation, energy absorption, floatability, high stiffness/weight ratio, and low cost per unit volume. Most of the properties of expanded polystyrene have a very obvious functional relationship with its density, so the manufacturer does not need to redesign the mold, and only minor adjustments to the actual operation according to the simple change of the processing technology. Other properties of the PS foam are also dependent on the type of polymer and the amount used in foaming. Since the mechanical strength of the foamed PS product can be adjusted by the foaming density, it is sometimes possible to obtain the desired strength by selecting another foam polymer.