2624 Chapter 22 



Quality distribution of pallet parts from low-grade lumber. — Large and 

 Frost ( 1 974) conducted a study of northeastern and southern hardwood lumber 

 to determine if the mix of lumber presently used to manufacture pallet parts is 

 good enough to provide the quality parts needed in exposed and vulnerable 

 areas of warehouse pallets identified as follows: 



• The two top deck endboards — 15 percent of total deck volume. 



• The two bottom deck endboards — 15 percent of the total deck volume. 



• The two outside stringers — 67 percent of total stringer volume. 



At seven mills a total of 20,942 board feet were graded and cut into pallet parts. 

 Species collected in the northeast included maple, beech, and birch; oak was 

 sampled from central Appal achia and oak, sweetgum, and black tupelo from 

 southeastern states. 



Large and Frost (1974) concluded that amounts of high quality deckboards 

 (Grade 2 and better) in existing pallet lumber mixtures are sufficient to permit 

 the placement of quality parts in the vulnerable peripheral parts of pallets. To 

 place Grade 2 and better stringers in outside positions (67 percent of stringer 

 volume) requires selective cutting, the use of higher lumber grades, lumber 

 sorting, or some other method of improving the quality mix. 



They found that there are significant differences in quality distribution of 

 pallet parts cut from different grades of lumber, and that selective cutting 

 yields a significantly larger proportion of high-quality parts than gang cutting 

 (fig. 22-33). There is, however, no appreciable difference in the quality of 

 parts cut from different species of lumber of comparable quality. 



See also: Craft, E. Paul; Whitenack, Kenneth R., Jr. A classification system 

 for predicting pallet part quality from hardwood cants. Broomall, PA: North- 

 east. For. Exp. Stn.; 1982; USDA For. Serv. Res. Pap. NE-515. 7 p. 



PARALLEL-LAMINATED-VENEER 



As further discussed in section 22-10, it is possible to rotary-peel thick oak 

 veneer and then bond the veneer into two- or three-ply sheets with grain of all 

 plys parallel. Such sheets can then be crosscut and ripped into pallet deck- 

 boards of desired dimensions. Kurtenacker (1975a) successfully used such 

 two-ply, ■y4-inch-thick, northern red oak deckboards, nailed or stapled to green 

 solid oak stringers, in field tests of reusable pallets for handling brick and 

 concrete blocks. 



In use, the laminated-deckboard pallets equalled the performance of those 

 with solid deckboards. During free-fall-on-corner drop tests, the 1 1 -inch- wide 

 edge deckboards provided more resistance to racking (had more rigidity) in the 

 plane of the pallet deck than did similar-size pallets that had a greater number 

 of narrower solid wood deckboards. 



No significant difference was found between laminated-deckboard pallets 

 assembled with pallet staples and those assembled with standard helically- 

 threaded pallet nails; thus, satisfactory performance may be expected from 

 staple-assembled pallets if about five staples are used for every three nails. 



