Expanded beads of polyethylene moldable at low steam pressure

Abstract

In this study, we explored an innovative approach to extrude expanded polyethylene (ePE) bead foam by utilizing a blend of two types of polyethylene, specifically low-density and linear low-density polyethylene. The intention behind this mixture was to enhance the molding process’s flexibility during steam chest molding. The outcomes of our investigation reveal the adaptability of the devised method and formulation, enabling the production of a broad spectrum of foam densities ranging from 20 to 100 kg/m³. Additionally, we achieved successful molding at remarkably low steam pressures, below 0.6 bar. Our research focuses on the strategic adjustment of processing parameters, including temperature and pressure, along with optimized die geometry for the extrusion foam process. To comprehensively evaluate the foamed molded components, we conducted a comprehensive mechanical and optical analysis. The findings underscore the flexibility and cost-effectiveness of ePE produced through foam extrusion. This method emerges as a promising alternative to expandable polystyrene, especially in applications requiring flexible materials and convenient recyclability without contributing to microplastic pollution in the environment.