image: The Chinese tallow tree produces popcornlike seeds in the fall and winter. view more
Credit: Photo by Jim Miller, USDA Forest Service)
A preliminary study by USDA FS Southern Research Station (SRS) researchers and cooperators shows that Chinese tallow tree, a nonnative invasive plant in the southeastern United States, holds promise as a material for bio-based composite building panels. In a technical note in the June 2006 issue of Forest Products Journal, the researchers report positive results from tests on three different types of panels made from Chinese tallow tree.
Because Chinese tallow tree grows rapidly, has seeds rich in oils, abundant flowers, and colorful fall foliage, it has been widely planted both as an ornamental and a crop across the Southeast. Now considered a noxious pest by the USDA Natural Resources Conservation Service, the plant has become a serious problem in east Texas, Louisiana, and Mississippi, where is establishes dense stands that quickly out compete most other tree species.
The rapid expansion of the Chinese tallow tree into Southern forests has lead to a call to investigate its possible uses in the forest products industry. The low density and light color of the wood make it an ideal candidate for producing composite panels, especially oriented strandboard, medium density fiberboard and particleboard, said Les Groom, project leader for the SRS Utilization of Southern Forest Resources unit in Pineville, LA, and co-author of the article with SRS research scientist Tom Eberhardt and technologist Chung Hse.
One of the barriers to using Chinese tallow tree for composites has been the fear that by developing an industrial use for the plant we would be encouraging people to plant more of it, Groom continued. But if it performs well as the sole material for composite panels, it should also perform well when mixed with other species. So, if mixed stands of trees are harvested commercially for use in composites, the Chinese tallow tree in the stand could be added in without affecting product quality.
Using standard industrial methods, the researchers produced three types of panels„Ÿflakeboard, particleboard, and fiberboard„Ÿand tested them for various mechanical and physical properties. Chinese tallow tree tested up to standards for all three panel types, with the woods relatively low density and high compaction ratio adding to its potential. We have heard anecdotally that buyers prefer brightly colored panels, so the light color of Chinese tallow tree might also work to its advantage, said Groom, who emphasized that the studies were preliminary, and that more research is needed on the basic anatomical, chemical, mechanical, and physical properties of the species.
Most research has focused on eradicating this plant rather than using it, said Groom. Finding a commercial use for Chinese tallow tree could actually underwrite efforts to control it.