Investigation and reduced production costs of Wood-Plastic Composite Profile Wall Coverings and Their Foam in Extrusion Process

This paper presents an experimental study on production of Wood-Plastic Composite (WPC) Profile Wall Coverings and their Foams (WPCF) in an extrusion process. The strength-pressure relationship could govern the selection process of the equipment (size), especially for the load bearing applications of WPCs. A modular die was designed and manufactured to produce cube-shaped profile products of various Thicknesses. The induced pressure was also recorded. In Foaming Process azodicarbonamide was used as the chemical blowing agent (CFA). Independent variables were selected as wood content (30, 45, 60 wt %), Die Thickness (15, 25, 35mm) and CFA content (0, 1%).Measured parameters were pressure, flexural strength, cost, density, specific strength (SS) and specific strength to cost (SSC). For design of experiments, central composite response surface was applied. Design-Expert software was utilized to analyze the data. The results showed that, for unfoamed WPC, as the pressure increases, the product strength increases noticeably. For WPC foams, the increasing the wood content caused increase in density, but decrease in cost, SS and SSC. Optimum condition to yield a high SSC occurs at two extremes of low and high wood content. Specific strength for WPCF showed 13 % higher than that of WPC. Besides, the analysis of results indicated the foaming WPC is effective wood content is below 45% in economical point of usage. (Style: Times New Roman, 10pt, Italic)