Hem-fir plywood were exposed to two brown rot fungi, Gloeophyllum trabeum and Postia placenta, and one white rot fungus, Trametes versicolor, to investigate the effect of fungal decay on mechanical properties of plywo...Hem-fir plywood were exposed to two brown rot fungi, Gloeophyllum trabeum and Postia placenta, and one white rot fungus, Trametes versicolor, to investigate the effect of fungal decay on mechanical properties of plywood. Results showed that modulus of rupture （MOR） and modulus of elasticity （MOE） of hem-fir plywood declined significantly by inoculating fungi, and weight loss of sample had a modest decrease. The fungi also made a greater effect on MOR than on MOE. Of three fungi, Postia placenta caused a most significant weight loss, and Gloeophyllum trabeum resulted in a largest flexural properties loss. Substantial declines in MOR and MOE of hem-fir plywood were also observed when the plywood samples were stored under wet conditions over 15 weeks, even in the absence of fungal attack.展开更多
The hot-press temperature curves were researched and effects of hot-pressing temperature,thickness of veneer and the numbers of layer on mechanical properties of laminated veneer lumber(LVL)were analyzed with emphasis...The hot-press temperature curves were researched and effects of hot-pressing temperature,thickness of veneer and the numbers of layer on mechanical properties of laminated veneer lumber(LVL)were analyzed with emphasis in the paper.Results showed that there was positive relationship between hot-pressing temperature and modulus of elastic(MOE);the modulus of rupture(MOR)of LVL was best when manufactured at 160 ℃.When the thickness of veneers was 3.25 mm the LVL usually destroyed due to veneer tearing;while when the thickness of veneers was 1.70 mm it easily splited in adhesive layer;the mechanical properties of LVL were best when the thickness of veneers was 1.70 mm;the 3 multinomial degrees of fitting the numbers of layers with MOE and MOR of Eucalyptus LVL matched very well,the R2 value were 0.951 6 and 0.981 2,respectively.展开更多
基金This research was supported by Forest Research Labora-tory, Oregon State University
文摘Hem-fir plywood were exposed to two brown rot fungi, Gloeophyllum trabeum and Postia placenta, and one white rot fungus, Trametes versicolor, to investigate the effect of fungal decay on mechanical properties of plywood. Results showed that modulus of rupture （MOR） and modulus of elasticity （MOE） of hem-fir plywood declined significantly by inoculating fungi, and weight loss of sample had a modest decrease. The fungi also made a greater effect on MOR than on MOE. Of three fungi, Postia placenta caused a most significant weight loss, and Gloeophyllum trabeum resulted in a largest flexural properties loss. Substantial declines in MOR and MOE of hem-fir plywood were also observed when the plywood samples were stored under wet conditions over 15 weeks, even in the absence of fungal attack.
文摘The hot-press temperature curves were researched and effects of hot-pressing temperature,thickness of veneer and the numbers of layer on mechanical properties of laminated veneer lumber(LVL)were analyzed with emphasis in the paper.Results showed that there was positive relationship between hot-pressing temperature and modulus of elastic(MOE);the modulus of rupture(MOR)of LVL was best when manufactured at 160 ℃.When the thickness of veneers was 3.25 mm the LVL usually destroyed due to veneer tearing;while when the thickness of veneers was 1.70 mm it easily splited in adhesive layer;the mechanical properties of LVL were best when the thickness of veneers was 1.70 mm;the 3 multinomial degrees of fitting the numbers of layers with MOE and MOR of Eucalyptus LVL matched very well,the R2 value were 0.951 6 and 0.981 2,respectively.
