Whether eating one for breakfast or packing one for lunch, few people give much thought to how oranges reach them from the groves of Florida or California. At Baird-Neece, on the other hand, they think a lot about oranges in transit. Nestled among the orange groves in Porterville, CA, this member of distributor Sunkist Growers, Inc., packs at least 14ꯠ cases of oranges daily-each case holding up to 88 oranges-for distribution in the U.S. and as far away as the Pacific Rim. Recently Sunkist, which sets material specs for some packaging components its members use, developed a new corrugated shipper with a glossier, brighter liner than the one used previously. Despite providing a better printing surface, this liner prevented case flaps from absorbing hot melt sufficiently, which in turn caused some cases to pop open during shipment due to changes in temperature. Baird-Neece plant supervisor Harley Nuckels explains. "If you're precooling [cased] fruit and placing it into a truck, the temperature will change. When it gets to market, the temperature changes again, and the top case on the display pallet has a tendency to pop open." He says that frustrated retailers were rejecting cases of oranges-and demanding a solution to this problem. While selecting a case is the decision of Sunkist Growers, selecting a sealing method is left up to the packing houses. Although other packing houses found other ways to combat difficulties encountered with the new cases, such as using taping systems, Baird-Neece elected to stick with the Nordson (Duluth, GA) hot melt system it was using on its Standard-Knapp (Portland, CT) Model 49 top and bottom case sealer. But how would the company achieve a long-term bond on its case flaps? Another obstacle was that the citrus case has die-cut holes for ventilation, making accurate adhesive placement critical. The single-wall C-flute standard RSC citrus container is produced by Fruit Growers Supply (Van Nuys, CA). It includes a 35#-test white liner that's flexo-printed in three colors. An open and shut case The solution was to add a Nordson cold glue system.The top adhesive station on the Standard-Knapp case sealer and the bottom one as well each includes two Nordson H-200 hot melt guns. Each gun applies a 3/32" half-round bead, 3" long, on the minor flaps of the carton. Simultaneously, eight Walcom(TM) LV217 liquid adhesive guns from Nordson (four guns per station) deposit cold glue beads on the major flaps using 0.3-mm dia nozzles. To assure the cold glue straddles the box vent holes, Nordson designed special gun-mounting brackets with a photoeye sensor and electronic timer. They move side-to-side up to 23/4" apart, allowing adjustable gun positioning. "We had a good Nordson unit," says Nuckels, "but hot melt alone couldn't handle the new box material and high-humidity conditions. Adding a secondary cold glue created a bond that would seal immediately and withstand our tough environmental factors," says Nuckels. The H-200 hot melt guns include Resistance Temperature Detector (RTD) sensors for precise temperature control and consistent viscosity. A Nordson Model 2304 applicator supplies the hot melt and provides a tank capacity of 18.7 lb and system melt rate of 20 lb/hr. The LV217 guns incorporate a zero-cavity needle for a sharp adhesive cut off, while helping prevent adhesive curing or adhesive sticking to the nozzle. A Walcom WM-60 piston pump from Nordson dispenses cold glue at a 12:1 fluid-to-air ratio. With their compact profiles, both the Nordson hot melt and cold glue guns retrofitted easily to the case sealer. "Nordson did a good job plumbing the system," says Nuckels. "The set-up is clean, efficient and easy to maintain." With the previous system, cases would even open up on the packaging line, resulting in downtime. Now, although twice the adhesive is being placed on cases, the system actually allows higher production, from about 1군 cases/hr to 1꼀 cases/hr. "You can increase by about four hundred cartons an hour," Nuckels says. In addition, he says, "There are very few rejects, probably nil." "We're now running at one hundred percent perfection," he states.
