Stretch Island Fruit Inc. Allyn WA manufactures “fruit leather”—dried strips made from all-natural 100% fresh fruit puree and formed into finished 2” x 4” bars. The line includes 13 different fruit flavors.
Traditionally the company had used manually fed production and packaging machines. But growing product demand and the impending expansion of the company’s production facilities offered the opportunity to upgrade and automate packaging operations.
The two existing wrapping machines were antiquated and were causing production bottlenecks as well as ergonomic and noise problems. The company uses a barrier-coated polyolefin-based laminated wrapping film from Flexstar Packaging that provides both low-temperature heat sealability and easy release properties to accommodate the sticky nature of the product. The proprietary-blend sealant film is 1.5-mil thick.
CEO Bob Sagerson had been investigating new packaging machinery options for some time. It appeared that the company would need customized feeding and packaging equipment to fully accommodate the stickiness of the fruit leather product at high speeds and would have to undergo a long design and integration process to achieve the desired packaging efficiencies.
Minimal customization alternative
At a packaging equipment show in San Francisco Sagerson witnessed demonstrations of packaging machines from various suppliers and was particularly impressed by the Linium 301 rotary head horizontal flow wrapper manufactured by Doboy Inc. part of the Packaging Technology Division of Bosch. The wrapper and accompanying robotic feeders as well as downstream interfaces are PC-controlled and the system enables pre-programmed product set-ups and fast changeovers.
The feeding system accepts randomly oriented incoming product on a wide flat-belt conveyor and the tracking system allows for continuous production flow. There is no need to stop and start the conveyor to pick and place products. And the crimper drive assures seal jaw alignment and quality seals on both ends of the wrapped packages.
Notes Sagerson “The flexibility of Doboy’s Linium 301 wrapper seemed to deliver the automation we needed without having to resort to a proprietary or heavily customized solution. We felt very comfortable committing to a proven system like Doboy’s. Their philosophy of using mostly standardized components in their machinery makes maintenance repair and replacement easier quicker and more cost-effective. The choice also offered us the advantage of much faster ramp-up and gave us a more flexible packaging solution at a lower price.”
Installation and start-up
Following a proposal and testing by Doboy Stretch Island Fruit purchased the Linium 301 wrapper and a two-robot Delfi infeed placer in May 2004. Sagerson notes “The equipment was first built and proven at Doboy. So overall lead time was about 4 months.” Stretch Island Fruit mechanics and packaging machine operators were sent to the Doboy facility in Wisconsin for training.
The Linium 301 rotary head horizontal flow wrapper offers the option of manual semi-automatic or fully automatic feeding. The biggest challenge for the fruit leather application was delivery of the lightweight moist cut leather strips in an irregular array through the wrapper’s 61¼2’ conveyor. Arranged in rows the fruit strips require a reliable degree of accurate placement to generate the highest levels of throughput. Doboy worked with Stretch Island Fruit to devise a variable speed conveyor with a servo-driven infeed that increased product placement accuracy.
The dual-robot Doboy Delfi infeed placer provides pick-and-place speeds up to 400 pieces/minute into the lug chain of the wrapper. The robotic arm suction cups were customized to accommodate the flimsy flexible nature of the fruit strip products.
Sagerson says “Once we got the parameters dialed in the robotics really shined.” In the past the moisture content and lightness of weight of the cut fruit leather strips had made gripper performance a challenge. The robotic infeed placer handles the strips with consistent reliability.
With only minor and quickly achieved refinements the new feeding and wrapping system is living up to Stretch Island Fruit’s performance expectations. Thanks in part to the Doboy packaging system Stretch Island Fruit can now produce 300 bars per day—more than double the output attainable with the previous feeding and wrapping equipment. The automated system also has enabled the company to save plant floor space and re-assign personnel and production resources elsewhere further increasing operating efficiencies. After wrapping the products are manually cartoned and cased in various volumes in a non-automated operation
“We like the flexibility of the feeding and wrapping system and the ability to quickly change to different product shapes and sizes” says Sagerson. “This flexibility has opened the door to new product ideas and we hope our growth will allow us to add a second system soon.”