Novel Manufacturing Processes for Polymer Bead Foams - T-Space
11
1 Chapter 1 Introduction 1.1. Bead Foam Technology Polymer bead foams with various 3-dimensional shapes can be manufactured using a sintering process of foamed beads. One of most frequently used bead foams is polystyrene (PS) bead foams. They are widely used in disposable coffee cups, coolers or cushioning material in packaging. Expandable PS (EPS) beads are polymerized in the form of fine polystyrene beads that contain 4 to 7 wt% of n-pentane, which means that the EPS beads are in an unfoamed state when they are sold and transported to a variety of molding manufacturers. Thus, the bulk density of the EPS beads is about 0.64 g/cm 3 and the transportation cost is reasonable. Molding manufacturers can perform pre-expansion with the expandable PS (EPS) beads using a pre-expander system. The pre-expanded beads have to be stabilized in a silo. This period is for the pressure equilibrium between internal cells and atmosphere. Following the stabilization period, the beads are ready to go through steam chest molding. It is the general procedure to fabricate EPS bead foams in industry.
Novel Manufacturing Processes for Polymer Bead Foams - T-Space
