This time last year, palletizing was a manual affair in the bulk packing area at Blue Diamond Growers cooperative in Sacramento, CA. But last summer the firm installed an automated palletizing system that neatly accumulates 25- and 50-lb cases from five different almond processing lines and sends them layer by layer to a smooth-running shuttle palletizer from Priority One Packaging (Waterloo, Ontario, Canada). As in years past, cases are printed with generic information by the corrugated supplier. But no longer do workers use roller printers in the warehouse to print variable information on cases, nor does Blue Diamond waste corrugated shippers by having those workers print more cases than are needed in a given shift. Instead, a software-driven ink-jet coding system from Foxjet (Arlington, TX) permits on-line printing of lot number, date code and bar code. The legibility of the codes is consistently good enough to allow bar code scanners from Accu-Sort (Telford, PA) to read them and determine, based on information in the code, which of five accumulation conveyors should receive each case. Each of the five Foxjet coders is located immediately after the five net weigh fillers responsible for filling the cases with whole, slivered, split, sliced or blanched almonds. Each high-resolution ink-jet printing system includes a Foxjet 7400 series controller connected to four printheads (two per side) and a case conveyor with integrated encoder for line speed monitoring. All printheads print images up to 1.9" tall. Overhead path As soon as ink-jet printing is complete, cases are taken by a vertical lift to an overhead conveyor system that carries them about 150' away from the filling area. Then they're lowered back to floor level by way of a serpentine conveyor that adds to the already considerable amount of accumulation space available. Next, cases move along a straight conveyor section that has five accumulation conveyors running off at a right angle. At the intersection of each accumulation conveyor, an Accu-Sort bar-code scanner reads the codes printed upstream by the Foxjet system. The scanners read the codes to determine which of the accumulation conveyors the cases should be diverted onto. When 10 cases are staged on one of the conveyors, a photocell detects it and they're released forward toward the palletizer. Designed specifically for companies with multi-line output, the palletizer carries up to five pallets at a time on its shuttle. This shuttle shifts constantly from one position to another below a stationary loading area. Pallets are automatically loaded into position on demand from a pallet dispenser. Slip sheets are placed automatically as well. Incoming cases first pass beneath the spray nozzles of a gluing system that deliver a stabilizing adhesive. Then cases are accumulated in full layers on a staging area. When a complete layer is formed, a transfer bar pushes the layer onto a layer plate. This plate lifts the layer to the appropriate height, and then a stripper arm sweeps the layer onto the pallet. As soon as the pallet receives its layer, the shuttle moves it away from the layer plate and positions another pallet in its place. Only when a pallet's final layer is in place is the pallet discharged to a downstream stretch wrapper. As Blue Diamond nears the completion of its first full year of automated palletizing, the gains in efficiency are beginning to impress not only Blue Diamond project engineer Darrell Nelson and his staff but the grower members of the cooperative. "It took some thought to put it all together," says Nelson. "But it's worked out beautifully."
