Study On Technique Of Sawing-Drying Ripping In Processing Small Diameter Oak Log

This paper narrated the contrasting production trial and its results as well as connected theoretical basis of domestic laminated board (the length of stud was not limited) from small梔iameter (14棗24cm) and low grade (grade3) oak logs using the technique of SDR and tradition according to principle of inner link and impact among sawing, drying and further processing solid products. On the basis of the relation between small梔iameter hardwood log?s outside specific feature and lumber recovery, sawing productivity, live? sawing was applied ,software was designed for maximum recovery main lumber sizes for different diameter logs ,the initial technology of break梤ebreak 梩rimming 梒ross cut was changed to break 梩rimming , a new measuring method and calculating formula for sawing deviation were used and target size was determined ,thus , the recovery for main lumber was increased by 1. 31% and sawing time was decreased by 5%. On the basis of the relation between small梔iameter hardwood log?s inside specific feature and the crook during sawing and drying, the flitch was sawn by live梥awing, the flitch restrained the release of the growth stress and the crook from the sides of flitch after sawing immediately: the flitch during drying balanced the growth stress, drying stress and drying difference in longitude; the humid stress during initial and middle drying stage was reduced by canceling presteaming and using low temperature drying: the remaining stress was removed by strengthening the conditioning, thus, the crook and other deformation during drying were controlled effectively and the percent of grade one and two for dried boards was increased by 24%. The results of production trial proved that the technique of SDR enhanced the wood utilizing percent. form log to planed lumber by 7. 81%, from log to laminated board by 5.41%, comparing with the technique of tradition, under the condition that the grade percent of planed lumber being not decreased when small梔iameter, low梘rade oak log was processed to domestic laminated board.