2712 Chapter 22 



oversize contour and the interior hollowed, leaving the wall Vs- to '/2-inch thick. 

 This rough-turned bowl is soaked in PEG for about 3 weeks. It is then dried to 

 about 7 percent moisture content, refastened to the lathe faceplate, and finish 

 turned until the walls are Vs- to '/4-inch thick, and the bottom about y4-inch thick. 

 To complete the bowl, polyurethane varnish is applied to the sides, the excess 

 base thickness cut off, and the bottom varnished. 



Procedural details for making other PEG-treated products can be found in 

 Mitchell (1972). 



22-14 PULPWOOD AND PULPCHIPS 



By 1978 pulpwood consumption in domestic mills had increased thirteenfold 

 since 1920, rising from 6. 1 million cords to 78.6 million cords (6.2 billion cubic 

 feet). The 1978 volume data includes 45.9 million cords of roundwood and 32.7 

 million cords of chips and sawdust obtained from slabs, edgings, veneer cores, 

 and other residues of primary manufacturing plus an unknown quantity of forest 

 residues. In addition, export demand increased almost 24 times to 11.8 million 

 cords (0.7 billion cubic feet). As a result of such growth, about half of the cubic 

 volume from domestic forests is used as pulpwood. By 2030, consumption of 

 pulpwood in U.S. mills is projected to be about 180 million cords (U.S. Depart- 

 ment of Agriculture, Forest Service 1980). 



Softwoods have long been preferred for pulp and paper products because of 

 their longer fiber and lighter color. In recent decades, however, use of hard- 

 woods has increased rapidly. In 1950 less than 15 percent of the pulpwood used 

 in U.S. mills was hardwood, but by 1978, hardwoods comprised more than 25 

 percent of the total. Such trends resulted from technological improvements in 

 pulping, availability of substantial volumes of hardwood at lower costs per ton 

 of fiber, improvement in properties of many grades of paper and board with the 

 addition of hardwood pulps, and rising competition and prices for softwood 

 timber. The trend toward increased use of hardwoods will be hastened by a 

 favorable supply situation; the proportion of hardwood fiber used in U.S. mills 

 should continue to rise, reaching about 32 percent in 2000 and 38 percent in 

 2030 (U.S Department of Agriculture, Forest Service 1980). 



Harvesting, manufacture, use, measurement units, and prices of pulpwood 

 and pulpchips are discussed elsewhere in this text, as follows: 



Subject Text reference 



Harvesting and storing Chapter 16 



Economics of forest residue chip harvesting Section 28-9 



The chipping process Sections 18-9, 18-24, and 



18-25 



Pulping Chapter 25 



Chip yields See Index under heading 



Pulp chips 

 Chippable residues See Index under heading 



Yields and measures, 



residues 



