[in Japanese]

View full abstract

In the plywood industry of Japan, imported timber was mainly used as raw material ; however, over 50% is the domestic material in recent years. As most of demand for plywood is from housing-related field, superiority in quake-resistance, energy conservation, durability and other functional characteristics are extremely important. In an effort to promote domestic demand for plywood products, various technical improvements such as anti-volatile organic compound (VOC) measures, reduction of odor during manufacturing process, and other environmental considerations are made. The promotion of the forest stewardship is essential in stably supplying the raw wood and is also an important factor in preventing further global warming ; therefore forest improvement must be aggressively carried out.

View full abstract

Wood processing involves sawing, drying, gluing, coating, and so forth. Among these procedures, drying may release relatively large amounts of volatile organic compounds (VOC) from wood. The 2004 amendment of the Air Pollution Control Law stipulates regulations to control VOC emissions from factories. The wood-drying process is not subjected to legal control but depends on a voluntary approach. Nevertheless, odors from wood-processing facilities and VOC emissions from wood products have raised concerns. This study examined the emission of VOCs during wood-drying.

View full abstract

To reduce the air pollution of large city in Japan, the air pollution control act was revised recently. The definition of volatile organic compound (VOC) and measurement of VOC concentration in factory were stated in the act. The regulation of the amount of VOC emissions from factory such as some painting and drying process were stated. Although adhesion and drying processes of wood-based material factories were not regulated, the factories have to take voluntary effort to reduce the VOC emission. Thus we investigated the VOC emission from wood-based material factories to support the voluntary effort to reduce the VOC emission. In case of the plywood factory, the VOC emissions from producing processes were included mostly the extractives of wood. With laminated veneer lumber (LVL) factory, the results of continuous measurement for VOC emission showed that VOC emission patterns were different between plywood and LVL hot press process. The amount of VOC emissions from adhesion process in overlay plywood and single layer flooring factories were very low level because of the correspondence of the sick house syndrome problem.

View full abstract

Some wood-drying processes discharge volatile organic compounds from the wood, and large amounts of condensed water including volatile organic compounds are obtained. In the case of coniferous wood, the main constituent is terpenoids, and the composition depends on the drying temperature. The main compounds in condensed water from sugi and hinoki wood are monoterpenoids such as α-pinene and limonene, sesquiterpenoids such as cadinenes and muurolene, and diterpenoids such as ferruginol. These have valuable properties including anti-microbial activity, anti-oxidant activity, deodorant activity, anti-termite and insecticidal activity, and relaxation activity.
This paper describes the contents of condensed water including volatile organic compounds during wood-drying.

View full abstract