Hardwood pallet cant quality and pallet part yields

Raw materials are the largest cost component in pallet manufhcturing. The primary raw material used to produce pallet parts are pallet cants. Therefore, pallet cant quality directly impacts pallet part processing and material costs. By knowing the quality of the cants being processed, pallet manufacturers can predict these costs and improve manufacturing efficiency. The purpose of this study was to develop and evaluate hardwood cant grading rules for use by pallet manufacturers and suppliers. Yield studies were necessary to accurately quantify the relationship between pallet part yield and cant quality. Twenty-eight yield studies were conducted throughout the Eastern United States at pallet mills producing parts from hardwood cants. Three preliminary pallet cant grades were used to segregate the cants according to the volume of unsound wood. A total of 47,258 board feet of hardwood cants were graded and processed into pallet parts. Pallet part yield and yield losses were determined for each preliminary cant grade. The average pallet part yield from the preliminary cant Grades 1,2, and 3 were 83,77, and 47 percent, respectively. Yield losses attributed to unsound defects were 2,8, and 39 percent for preliminary Grades 1,2, and 3, respectively. It was shown that although the grade rules produced statistically different quality divisions between grades, amore practical approach is to establisha single minimum cant qualitybased on yield and an economic assessment of cant and pallet part value. A new cant grading procedure is proposed specifying a single cant grade permitting up to one-third (33%) unsound volume. I n "price taker" markets, successful firms are the low cast producers, and pallet manufacturers are no exception. The single largest cost component of pallet manuhcturing is raw material costs. Cants and lumber typically account for over 60 percent of the operating costs. In the last two decades, cants have replaced lumber as the primary raw material for hardwood pallet manufacturers (Reddy et al. 1997). As stumpage prices and competition for wood-based raw materials increase, pallet cant prices will continue to rise as well. The value of cants to pallet manufacturers is a function of pallet part yield and sawing costs. Knowing the value of cants will help pallet manufacturers more accurately control costs and price products. Even though pallet cants are the largest volume hardwood lumber product produced in the United States, no standard grading rules exists for this product. The National Hardwood Lumber Association (NHLA) provides grading criteria for Common Timbers and Industrial Blocking that indicate the allowance of unsound wood as long as strength for intended use is not impaired due to this defect (NHLA 2003). However, unsound volume restrictions and size and number of cutting units are not specified. Several studies over the last 30 years have examined the relationships between hardwood cants and the yield and quality of pallets parts obtained from them (Craft and Whitenack 1982, Craft and Emanuel 1981, Large and Frost 1974, W~tt 1972). Most recently, a study by Araman et al. (2003) examined the The authors are, respectively, Operations Manager, Atlanta Hardwoods Corp, Mableton, GA @itchell@ hardwoodweb.com); Professor, Dept. of Wood Sci. and Forest Prod., Virginia Tech, Blacksburg, VA ([email protected]); Project Leader, USDA Forest Serv., Southern Res. Sta., Blacksburg, VA ([email protected]); and Research Associate, Dept. of Wood Sci. and Forest Prod., Virginia Tech, Blacksburg, VA @[email protected]). This paper was received for publication in March 2005. Article No. 10019. %Forest Products Society Member. OForest Products Society 2005. Forest Prod. J. 55(12):233-238. FOREST PRODUCTS JOURNAL VOL. 55, NO. 12 percentage of unsound volume in hardwood pallet cants. This research shows that significant proportions 90 percent of hardwood cants have less than 10 percent unsound volume, and that only 2 percent of cants have more than 30 percent unsound volume. This study, as well as the others, supports the justification that cant quality can and should be assessed in order to predict pallet part yields and to better control raw material costs.