Challenge to the Production of Fine Wood—Plastic Injection Molded Composites

This paper presents an experimental investigation on injection molding of wood-plastic composites where the wood constituents are very fine in size (below 50 micron). Moisture and water absorption, MFI values, and shrinkage values were also measured for various wood contents from 40% to 70%. The results indicated that the moisture content is highly increased when adding wood content to 70%. MFI measurement also exhibited a very large drop when adding wood content from 60% to 70%. The prediction was that the conventional injection molding of the composites with 70% content of very fine wood particles would be highly challenging. The experiments in molding process revealed that while modification of sprue design and increasing mold temperature could enhance mold filling for wood contents up to 60%, but for the composite of 70% wood content, the mold filling was incomplete.