United States Department of Agriculture, Forest Service, Forest Products Laboratory, General Technical Report FPL-GTR-91
Filled thermoplastic composites are stiffer, stronger, and more dimensionally stable than their unfilled counterparts. Such thermoplastics are usually provided to the end-user as a precompounded, pelletized feedstock. Typical reinforcing fillers are inorganic materials like talc or fiberglass, but materials derived from waste wood, such as wood flour and recycled paper fiber, are also effective as fillers. The goal of this project was to generate commercial interest in using waste-wood–paper-derived fillers (WPFs) to reinforce thermoplastics. The research strategy was twofold: developmental research and outreach. Specific objectives were (1) to improve wastepaper fiber preparation, feeding, and compounding methods, and optimize composite performance, and (2) to communicate to end-product manufacturers the advantages of WPF thermoplastics.
The research was led and supported by the Forest Products Laboratory (FPL), with input from a consortium of 15 fiber suppliers and plastics manufacturers. Additional funding was provided by the Wisconsin Department of Natural Resources. Equipment was leased and installed at FPL. Eight general purpose formulations were developed—they included extrusion and injection molding grades of both polyethylene and polypropylene, reinforced with WPFs. An information packet containing performance data, appropriate processing conditions, sample pellets, sample parts, and a questionnaire was sent to nearly 500 commercial
plastics manufacturers in Wisconsin, Illinois, and Michigan. In response to requests for in-house trials, FPL researchers conducted nearly 18 site visits. The researchers ensured proper handling of the material, provided consultation, and gathered information about processing and performance. The trials went very well, and parts were successfully manufactured at all facilities. Products included automobile trim components and housings, vacuum cleaner parts, paint brush handles, bicycle parts, cosmetic cases, and other household items. Great interest has been shown in the use of WPF thermoplastics; one consortium member is establishing a 4 million kg/yr (9 million lb/yr) facility. Total market demand is conservatively expected to exceed 45 million kg/yr (100 million lb/yr).
English, Brent et al. 1996. Waste-wood-derived fillers for plastics. USDA Forest Service, Forest Products Laboratory, General Technical Report FPL-GTR-91. Madison, WI