2640 



Chapter 22 



Figure 22-39. — Mechanized pallet assembly line incorporating two nailers, (or manu- 

 facture of pallets 24 to 60 inches in length and 26 to 50 inches in width. (Drawing from 

 Viking Engineering and Development Incorporated.) 



RESIDUES FROM PALLET MANUFACTURE 



As lumber cost represents close to 50 percent of the selling price of a wood 

 pallet, knowledge of degree of utilization is essential to successful operation. 

 (See also table 27-122A and paragraph Yield of pallet cants and lumber in 

 subsection PALLETS, section 27-2.) 



A small amount of the hardwood lumber purchased by pallet producers is 

 sawn for the furniture and flooring markets. Such lumber is usually in thick- 

 nesses of 1 or 2 inches. National Hardwood Lumber Association standards allow 

 rough boards to be sawn from Vs- to y4-inch-thick in V^s-inch increments and V4- 

 inch to 2 inches thick in V4-inch increments. The pallet manufacturer usually 

 purchases cants and lumber in the thickness needed so that remanufacture is 

 efficient. Cants are surfaced on two sides and resawn to final dimension. Hard- 

 wood pallet lumber is usually purchased to specified dimensions nominally 4 

 and 6 inches wide, and stringers to nominal 2- by 4-inch dimension. With good 

 purchasing and manufacturing procedures, residues from surfacer and ripsaw 

 can be minimal. Notching machines, trimmers, and cull boards create substan- 

 tial residues, however. In a closely controlled operation, residues may total 12 to 

 15 percent of incoming wood. Not all operations are so efficient, however. 



Perry (1976) analyzed residues from nine pallet plants in Ohio, Kentucky, 

 Tennessee, and Alabama. He found that 30 to 40 percent of the weight of lumber 

 admitted to production lines was converted to residues during manufacture of 

 pallets. Six to 18 percent is lost as surfacing residue, 6 percent at the cutoff saws, 

 and another 7 to 19 percent at the ripsaws. Five percent of the weight of end 

 deckboards is converted to residues during chamfering, and 7 percent of stringer 

 weight during notching (fig. 22-40). 



Perry found that a thousand board feet of input lumber had ovendry weight 

 and moisture content varying with species, as follows: 



