Virginia Tech wood scientists hope that their vacuum-drying project will benefit wood pallet and container manufacturers and hardwood sawmill businesses not only in the state but across the nation.

"The vacuum controlling system eliminates the need for a heating system, saves energy, and does not release ozone-depleting chemicals into the earth's atmosphere," says Zhangjjng Chen, one the researchers working on the project at the Center for Unit Load and Design in the wood science and forest products department of Virginia Tech's College of Natural Resources.

"Plant sanitary measures currently require that wood pallets and containers which pack goods that are imported or exported should be heat-treated or fumigated," Chen explains. In response to these requirements, the Center for Unit Load and Design is developing the basis for vacuum control of insects in solid wood packaging materials, which would serve as an alternative to the current method of eliminating insects in wood.

Chen and his research partners project that low pressure, achieved by applying a vacuum to a system, will create an environment sufficiently low in oxygen that will eliminate the insects in several hours to days. Their research data indicates that there may be an opportunity to apply this technology to eliminate insects in wood.

The material being tested is freshly cut red oak. Larvae of the longhorn beetle, Hylotrupes bajulus, will be used for all of the evaluations and will serve as a substitute for the Asian Longhorn Beetle, Anoplophora glabripennis because life stages are approximately the same. Experts believe the Asian Longhorn Beetle was introduced in America via infested shipping materials.

Principal investigators responsible for the vacuum control project include Virginia Tech's wood science and forest products research specialist Zhangjjng Chen, professor Marshall White, along with entomologist professor William H. Robinson. Chen and White work with the wood and moisture relationship that occurs in vacuum drying. Robinson is an entomologist, who has extensive knowledge on wood insects.