Solid Wood Products 



2565 



1.0 TON 



BARKY 



SAWLOGS 



FUEL 

 .23 



TOTAL 



1 .00 TON 



Figure 22-1. — Materials balance for manufacture of y4-inch-thick, tongue-and-groove 

 oak flooring, based on ovendry weight. Sawiog weight includes bark. (Drawing after 

 Koch 1976a.) 



Hardwood lumber varies substantially in thickness. Applefield and Bois 

 (1966) measured lumber in 16 furniture plants at 12 locations in North Carolina 

 and found that 19.7 percent had miscuts, 16.0 percent was too thin, and 1.7 

 percent was oversize for a total of 37.4 percent mismanufactured. Sawing 

 variation cannot be eliminated, but it can be reduced. Besides the cost in loss of 

 lumber recovery, oversizing increases the cost of kiln-drying by decreasing the 

 number of boards in a kiln charge, shortening sticker life, and increasing kiln 

 time required for drying. Simpson and Tschernitz (1978) computed that an 

 increase in red oak thickness of 3/32-inch increases drying time more than a day 

 and drying cost for 4/4 lumber by about $5 per thousand board feet. 



Higher lumber recoveries can be attained through training, improvement of 

 equipment to reduce sawing kerfs and tolerances, change in sawing patterns, and 

 improvement of cutting accuracy. New sawmills should incorporate reliable 

 thin-kerf sawing equipment and proved automated saw and log positioning 

 equipment. To aid mill managers in evaluating the economic feasibility of 

 sawmill improvement, Harpole (1977) provided a procedure to estimate the 

 break-even point at which costs equal anticipated benefits. 



Sawiog values. — Martens (1967) commented that if the value of hardwood 

 lumber had increased at the same rate as the cost of producing it, abandoned 

 sawmill sites would be less common; in the Appalachian region some 2,800 

 sawing and planing mills (about 40 percent of the operating plants) went out of 

 business between 1948 and 1958 and the trend continues, in general, the very 

 large and the very small mills are disappearing, and surviving intermediate-size 

 mills are becoming more automated. 



Success in the hardwood sawmill operation requires good estimation of true 

 sawiog value and knowledge of how changing hardwood lumber prices affect it. 

 Martens (1967) computed these changes for the period 1955-1965; in general. 



