Effects of the removal of matrix substances as a pretreatment in the production of high strength resin impregnated wood based materials

摘要: The unique microstructure of wood has many anatomical features, which provide both high toughness and strength wood. Considering its outstanding the fact that Young’s modulus microfibril, a cellulose crystal framework cell wall, reaches 140 to 150 GPa, it is believed possibility be basis for materials. For this reason, we are studying production based materials using low molecular weight phenolic resin impregnation followed by heat curing under compression [1–5]. wall composed 50% matrix substances, such as lignin hemicellulose, whose mechanical properties not microfibril. Thus, in previous report [5], studied effects removal substances pretreatment alkaline cooking most widely used procedure pulping remove Veneers Hoop pine (Araucaria cunninghamiii) were treated with NaOH + Na2S aqueous solution (25% active alkali, 25% sulphidity) at 120 ◦C or 135 4 h, resulted 20% loss. These veneers subjected (PF resin) after parallel lamination, higher bending than without obtained. However, when temperatures 170 further increment could observed despite an increase loss up 30%. results analysis Klason showed due study mainly attributable hemicellulose. was considered requires temperature also causes damage kind carbohydrate same may result reduction properties. Hence, study, obtain less NaClO2 treatment hemicellulose combination mild conditions attempted veneer work [5]. (70 g), dimensions 80 mm longitudinal direction (fiber direction), 60 cross 1 thickness 45 12 h 2000 ml 2% pH 4.5. This repeated 3 times rinsing running water 2 h. reached 14% 24% concentration 2%, respectively shown Table I. After drying, these samples then soaked 10% PF (Aika Ko-gyo Co. Ltd; average weight, 200, 8) reduced pressure three days. dried successively room 7 days 70 gain untreated 21 23%, respectively. impregnated laminated (nine-ply) compressed MPa 160 specimens cut (longitudinal direction) 10 (cross-longitudinal direction). final about mm. conditioned 90 regulate moisture content before point testing cross-head speed 5 mm/min test span 50 Instron 1185 universal machine. As I, improved treatment, 40% (control) density. effect on between 20 30%