Low cost polyolefin composites containing pulp mill wood residue

Abstract

Abstract Pulp mill wood residue was tested for its suitability as a filler for polyolefins. Samples of wood residue (residue from screened chips) were obtained from three southern kraft pulp mills. Screen analysis of the residues indicated that from 2 to 10 percent, by weight, passes a 48 mesh screen. The aspect, or length to diameter, ratio of the wood residue varied from 3 to over 19, compared to 2.5 for commercial wood flour. While the ash content of the residue was high, its lower cost and higher aspect ratio compared to wood floor indicated potential as a polymer filler. Composites of polyethylene and polystyrene with the wood residue were extruded and then injectionmolded into tensile bars. The results indicate little difference in extrusion torque, tensile modulus, or drop‐ball impact strength between composites containing wood residue and wood flour.