Construction variables considered in fabrication of a structural flakeboard

Abstract

Flake geometry, flake quality, flake alignment, average density, density gradients, layer thicknesses, and resin content were factors considered in determining the final construction details on structural flakeboards made from 1) western softwoods and 2) southern hardwood residues. After making compromises between board properties, a three-layer design was recommended for both board types. Long, thin face flakes enhanced bending properties while thick core flakes maximized internal bond strengths. The lower compaction ratio associated with high-density hardwood species restricted the range of the variables used, as compared to those considered by the softwood board. The use of high quality surface flakes and a surface water spray were other methods used to improve the performance of the hardwood board. Alignment of face flakes substantially increased the bending properties in the aligned direction for both board types. Being bound on one hand by economics and on the other by strength and durability requirements, a liquid phenolic resin content of 5 to 6 percent was used for the binder. By carefully choosing construction variables and fabrication techniques, acceptable panels from forest and mill residues were recommended for structural application.

Citation

Geimer, R.L.; Price, E.W. 1978. Construction variables considered in fabrication of a structural flakeboard. Structural flakeboard from forest residues : proceedings of a symposium presented by the USDA Forest Service, June 6-8, 1978, Kansas City, Mo. Washington, DC : U.S. Dept. of Agriculture, Forest Service, 1978. Gen. Tech. Rep. WO-5: Pages 69-80