Like the packaging industry itself, secondary packaging is largely specialized, reflecting an incredible variety of product parameters, from shape to size to consistency. But unlike primary packaging, which is normally done at high speeds and thus almost impossible to perform by hand, case packing is often a manual function, especially in moderate volumes or in the early stages of a product lifecycle.
Any number of considerations—rising wage, high employee turnover, ergonomics, tighter food safety regulations—can spur a food processor to automate the pack-off process and redeploy the workforce into higher value activity.
Equipment options span a wide range of devices, from single function machines to sophisticated integrated systems.
For products packaged in a clamshell, especially fresh foods like tomatoes and salad greens, the use of robotics is an increasingly popular solution. With its benefits of longer shelf life, less waste, and a higher likelihood of selling, the clamshell is becoming something akin to a holy grail for several categories of food products, reports John Dulchinos, CEO of Adept Technology.
However, case packing the rigid clamshells presents challenges. There is scant margin for error on the fit of each package in the case. Unlike flexible bags of frozen vegetables, for example, which can be shifted and shaken to fit in a carton, clamshells require exacting placement to ensure case alignment for sealing and further handling.
The precise transfer of the clamshell to its designated space in the carton is the perfect kind of task for a robot. In both primary and secondary packaging, one of the biggest constraints is how to pick up the product gently without damage, hygienically and very fast. According to Dulchinos, Adept has developed special capabilities for clamshell handling, starting with the gripper. “The company’s SoftPIC product line is “a really elegant solution” for handling not just clamshells but also odd-shaped products--bags of fresh foods in their natural state, like apples and oranges, for example.
To deal with the individuality of each application, Adept relies on three-dimensional technology in both sensing and printing technology so it can create uniquely-designed grippers for products very quickly. “This means we can go into applications that were previously not possible because the item couldn’t be picked up,” Dulchinos says. “Our robots can handle the product and do so at a rate that makes financial sense, without contamination or product damage.”
Another value robots bring to these tasks is their adaptability. Vision capability allows them to discern irregularities like random orientation so they can dynamically adjust to product flow. They can be quickly reconfigured for new applications through software controls. That comes in handy when food processors face sudden shifts in customer-driven parameters, such as a new package size or display position.
Robots also have a strong advantage in managing cleanliness, limiting the spread of contamination and offering better product protection. They promote the separation of people and product. Their grippers present a sterile surface for product contact. Tools can be quickly detached, and the units are easy to sanitize.
The boost to productivity is evident in the case packing operations of southern California’s Earthbound Farm, where Adept robots turn in a flawless performance depositing clamshells of produce into cartons. “Robots can perform these highly repetitive packaging operations at exceptional levels of efficiency, throughput and consistency,” Dulchinos observes.
Food processors concerned about efficiency can elect to combine the three steps of case erecting/forming, filling, and closing in a single piece of equipment. Integrating previously separate machine functions into one system is a primary focus of The Aagard Group, relates President Steve Mulder.
Seen as a “major differentiator,” Aagard’s all-in-one approach eliminates the duplication of effort inherent in transferring a case through three separate pieces of equipment, each with its own power drop and control system. The act of letting go of a package and regaining control in the next function is in itself very inefficient, Mulder points out.
In addition to being more productive, all-in-one units take up a lot less floor space and require fewer operators. Machines can be placed closer together, and one person can tend all three functions.
Because applications are so product-specific, Aagard does not have a fixed product line. Every machine the company makes is custom designed and engineered to meet processor needs, which can vary considerably according to product handling, line speed, case range, and other factors.
Systems can be designed either to form or erect cartons. Packing can be done through a variety of methods—gravity drop, a vacuum device, even an articulated robotic arm. “We may take a complete load and push it into the case when doing a bag-in-box line, or we could build one layer at a time, place it into the case, and then put another layer on top,” says Mulder.
For further economies, Aagard can add a case palletizer to the back end of the machine frame. All system functions are integrated into a single control unit, and the configuration can cut square footage needs in half. “Sometimes fitting a machine into a small area can be a bigger challenge than product handling,” he remarks.
Erectors and Sealers
When it comes to individual machines on the pack-off line, A.B. Sealer manufactures both case sealers and case erectors. According to company spokesperson Jennifer Miescke, a prime consideration in case erecting is the quality of the seal. “If the box isn’t squared and sealed properly, it won’t flow down the line. Everything must be perfect,” she notes.
Reliability is also key as this equipment is expected to run 24/7. Engineered with fewer moving parts to streamline operation, A.B. Sealer equipment lends itself to “set and forget” environments, Miescke says. The Piranha tape head, the company’s own design, incorporates features such as positive tape support and a thick blade with deep sharp points for consistent cutting that enable it to work dependably with all types of tape and carton weights.
Just as cartons are typically custom-sized to fit product for minimal waste, A.B. Sealer custom builds case erectors based on processor needs. Machine speeds vary according to box size: 12 per minute for large cartons, 18 per minute for small cartons.