Sorting with the Experimental Line 



The table on which apples were sorted was of a new design (fig. 3). It 

 looked much like the well-known wooden-roller type table but in performance 

 was quite different. The rollers were aluminum, 2-3/8 inches in diameter, 

 and spaced 3 inches on center. Unique features of this sorting table were: 

 (1) Independently controlled rate of translation, (2) independently controlled 

 rate and direction of rotation, (3) table surface divided into lanes, (4) cull 

 disposal chutes located at side of table--one for each sorter, and (5) brusher 

 located at discharge end of table, so that apples were sorted before brushing. 



During the testing period rollers traveled at 30 feet per minute, and 

 rotated in a reverse direction at 94 revolutions per minute. By rotating the 

 rollers in a reverse direction, apples were caused to roll in a forward 

 direction. It had been established in other research that objects are easier 

 to sort when they rotate forward. 1/ 



At a roller rotation rate of 94 r.p.m. an apple measuring 2-3/4 inches 

 in diameter would rotate 8 times while in a sorter's field of vision. Smaller 

 apples would rotate more times, and larger apples fewer. This rate of rotation 

 offered ample opportunity for a sorter to detect a defect on an apple--if the 

 defect were on a visible part of the apple's surface. After detecting and 

 removing a defective apple, the sorter then had to decide if it were utility 

 or cull grade, and dispose of the apple accordingly. 



Tests were conducted to determine whether the complete sorting job 

 could be performed at the sorting table, so that packers would not have to re- 

 inspect the apples before packing them. If this could be done, productivity 

 of the packers would be more than doubled. But for such a sorting procedure 

 to be successful, no more off-grade apples could go into packed fruit than did 

 when each apple was individually reinspected by its packer. 



Test samples were taken of fruit (1) at the dumper, (2) after it had 

 been passed by the sorters, (3) in cartons of packed combination U. So Extra- 

 Fancy and U. S. Fancy apples, and (4) in boxes of jumble-packed utility fruit. 

 By sampling at each of these points, it was possible to evaluate the effective- 

 ness of the sorting performed at both the sorting table and the packing stations, 



Sorting at the Sorting Table 



In this operation, sorters removed some two-thirds of the utilities, and 

 virtually all of the culls. The actual percentages depended on the number of 

 sorters, dumping rate, and percent of lower-grade apples in the orchard-run 

 fruit. In addition to removing the lower grade apples, sorters also separated 

 culls and utilities, so that these two grades could be boxed separately. 



1/ Malcolm, D. G. , and DeGarmo, E. P. Visual Inspection of Products for 

 Surface Characteristics in Grading Operations. U. S. Dept. Agr. Mktg. Res. 

 Rpt. 45. June 1953. 



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