Physical properties of strawboard as affected by processing parameters

Wheat straw has been recently considered as an alternative to wood fibers i n manufacturing particle boards. The objective of this study was to investi gate the effects of processing parameters on straw particle board quality. Commercial ground wheat straw was used in a full factorial experimental des ign to examine the effects of three processing variables (initial straw moi sture content (MC), resin binder content (BC), and press temperature) on st rawboard physical and mechanical properties. The MC was tested between 2 an d 12%, BC between 2 and 8%, and press temperature between 135 and 218 degre es C. Strawboard density was held constant by controlling the gap in the pr ess mold. Dimensional stability and water resistance was determined by a 24 -h water-soak test, and mechanical properties by a three-point flexural tes t. In the tested parameter range, BC was the most significant factor affect ing the strawboard dimensional stability, water resistance and mechanical p roperties. Initial straw MC was the second most significant factor influenc ing strawboard quality. MC had a more significant effect on board mechanica l properties than on dimensional stability. Press temperature had a more si gnificant effect on the strawboard dimensional stability than on mechanical properties. (C) 2000 Elsevier Science B.V. All rights reserved.