SUMMARY - Economic, social, and political pressures in recent years have defined the need for improved use of this Nation's natural resources and, in particular, forest products. This has resulted in a paradigm shift in the production of forest products: the wood fiber source in no longer thought of as an abundant and inexpensive raw material but as a material which must used wisely and efficiently. As such, the primary research in our unit centers on the basic tenet of composite engineering: to reassemble wood
constituents in the most efficient manner into a composite with optimum structural properties. This component focuses on the contribution of the basic reinforcing component, which in most mill environments in the Southern states is the wood fiber, to
the overall structural performance of the final composite. Most of the studies are empirical in nature and focus primarily on the relationship between fiber furnish mechanical properties and the resulting structural performance of accompanying fiberboard or paperboard end-product.

CURRENT COLLABORATIVE RESEARCH - Our research unit focuses primarily on the efficient utilization of woody material as it relates to the forest products industry. Although the research is quite varied in nature, we currently conduct several collaborative projects with the University of Southwestern Louisiana Microscopy Center.

Individual Fiber Stiffness and Strength

Tensile testing of individual wood fibers has been ongoing on commercially-important Southern softwood species to establish a database of mechanical properties for the development of wood fiber-based composites. This research, which is funded by the USDA Forest Service and the Composite Panel Association, focuses on the effect of processing and recycling on wood fiber mechanical properties as well as quantifying the mechanical properties of alternative fiber sources such as flax, bagasse, and others. The confocal laser scanning microscope (CLSM) has been used to determine fiber cross-sectional areas and thus allow us to determine engineering properties such as ultimate tensile stress and Young's modulus. This information will allow manufacturers of wood fiber-based composites to make stronger panels with a more efficient use of wood volume, thus lowering the demand for timber harvesting.

Fiber Surface Morphology

One of the mechanisms which govern the structural performance of wood fiber-based composites is fiber-to-fiber stress transfer. We are currently quantifying the effect of pulping regimes on the surface roughness and subsequently developing predictive models relating surface properties and paper stiffness and strength. The USDA, National Research Initiative Competitive Grants Program-funded study uses the atomic force microscope (AFM) to physically observe fiber surfaces and assign numerical values which relate to fiber-to-fiber stress transfer.