Production process of laminated veneer lumber
Suitable for application: structural plywood
I. General Situation
Laminated veneer lumber (LVL) is a new type of man-made wood, which is made of small diameter and low quality logs, and is cut into veneers with thickness of more than 3 mm and bonded with parallel-grain blanks. LVL not only retains the natural characteristics of wood, but also has the structural characteristics that solid wood sawdust does not have. It has small strength variability, high allowable design stress and good dimensional stability. Products can be used in building components, building interior decoration, furniture, car and train compartment boards, container boards, etc., with a wide range of applications. The research of LVL as a new type of sheet began in the early 1970s. First, American and Canadian research institutes developed the manufacturing technology of LVL almost at the same time. Then Finland built the first LVL production line in 1976. At present, there are 19 LVL production lines and factories in Japan. In addition, Australia, South Korea, New Zealand, South Africa and Russia all have LVL industrial production. LVL consumption in North America reached 8 million in 1993 and is expected to reach 24 million in 2002.
II. Production process
The production process of this technology is as follows: small diameter log – , truncation – , softening of wood segment – > peeling – , veneer rotary cutting – , shear – ,drying – , gluing – , matching – , high frequency hot pressing – , sawing – ,LVL board square timber,.
China’s forest resources are scarce, veneer timber is scarce, large diameter timber is becoming less and less, and in the 1960s, a large number of artificial forests have been built with low-quality timber, so plywood timber is in short supply. It is an effective way to use small-diameter wood and low-quality wood to produce veneer laminated lumber to meet the needs of car and construction materials in China. At present, the annual demand for high-quality automobile car panels in China is more than 60,000 cubic meters, while the demand for railway car panels is more than million cubic meters. The construction furniture industry is also an excellent market for LVL. LVL can also be used for formwork beams, columns, brackets and sleepers. Therefore, LVL has a broad and good application prospect in China.