- 15 - 



On the unit shown the average time for emptying a 27-box pallet box was 

 approximately 7 minutes of which 1-3/4 minutes was spent changing boxes. With 

 a more convenient, efficient installation, the percentage of time required for 

 changing would be less. The rate of operation, which was about 215 loose- 

 filled boxes per hour, depends on the size and speed of the grading crew. As 

 the rate increases, the percentage of time required for changing boxes increases 

 With the operation shown, there was an accumulation of apples in the old-style 

 washer used in the packing line just ahead of the grading crew. This permitted 

 evening out the flow to the grading crew so that they received almost a con- 

 tinuous flow of fruit. 



A pallet-box dumper of the type shown in figures 15 and 16 costs around 

 $500. This unit was satisfactory and saved the plant operators considerable 

 investment over the larger capacity box dumpers. Their planned operations 

 will require handling from 500 to 1,000 pallet boxes per season. 



The other system using lower-cost pallet-box emptying equipment 

 necessitates the use of an emptying door or end gate in one side of the box. 

 Such an addition to the box costs an estimated one dollar per box and, with 

 large-scale operations, might equal the cost of a dumper. Pallet boxes wit 

 the trap door are rolled or lifted into place and tipped to a maximum of 

 about 30 degrees with a suitable mechanism. Opening the door allowed the 

 apples to flow out onto the conveyor at the start of the packing line. 



No comparative fruit injury studies were made in Washington in 1957 

 between the box-inverting and the trap-door types of dumpers. Tests were made 

 in British Columbia with both types of emptying and the results with each 

 were reported to be comparable as far as fruit marking or other injury was 

 concerned. 



TYPES OF PALLET BOXES STUDIED 



In conducting the research, it was necessary to limit the number of 

 different types of pallet boxes to be considered. Eleven types were studied 

 in all but the cooling studies. Four were constructed by the Agricultural 

 Research Service, 3 were already in commercial use, and 4 were constructed by 

 the Agricultural Marketing Service for plant handling, cooling, and storage. 

 Dimensions and structural features of the 11 pallet boxes studied are shown in 

 table 1. 



The 4 ARS pallet boxes are actually 2 types — one uses plywood sides, the 

 other tightly spaced individual boards. All ARS pallet boxes have spaced 

 bottoms. Outside heights are 30 and 32 inches. All 4 are mounted on 4-way 

 pallets. 



The 3 commercial pallet boxes for which data were developed included 

 one lined with fiberboard, the second had solid sides and solid bottoms with 

 1^-inch slot around the bottom, and the third had spaced sides and bottom. 



