When to automate: Conventional and robotic applications
Fitting the right modular conventional, robotics, or hybrid motion control system to an automated palletizing application increases flexibility for adapting to future applications and increases return on investment (ROI) for such systems.
Since the 1950s, conventional automatic palletizers have brought speed and reliability to manual warehouse processes. In the 1990s, gantry and jointed-arm robots made significant inroads into palletizing, giving operations more automation choices than ever before. Certain applications are better suited for robotics, while others favor conventional automation. It’s important for operations to choose a palletizing technology that best fits their current and future material handling needs, and offers a sound business case for automation.
Applications favoring robotics
Articulated-arm robotic palletizers are viable solutions for high-SKU, lower-speed operations as well as applications where irregular or varying product shapes demand the precision of a robotic arm, such as bags or pails. [SKU stands for stock-keeping units, numbers or codes associated with particular products.]
Low-speed multi-lines – To handle more than one product at a time, an upstream conveying system needs to accumulate layers or loads of like product, then feed them into a palletizer that automatically changes stacking patterns. A palletizing robot can simplify multi-line palletizing by eliminating the upstream conveyor system. Several loads can be built inside the robot work envelope, allowing the arm to work on all of the loads at the same time while storing the partial loads in cubic form at floor level. This is a very effective method for lower-speed lines that generally operate at rates under 15 cases per minute, per line.
Bag palletizing – Jointed-arm robots dominate the bag palletizing business. Clamshell tooling allows the robot to pick the bag from a roller conveyor and place it on the load without disturbing the contents of the bag, resulting in a square load. Furthermore, robots can achieve higher rates palletizing bags than cases, frequently above 20 bags per minute. Robotic arms that offer the ability to work in confined spaces and dusty environments enhance their appeal in bag palletizing.
Pail palletizing – Most pails are constructed so that the bottom of the pail nests inside the lid of the pail below when stacked on a pallet. Robots can precisely position pails so that each layer nests inside the previous layer, making pail palletizing an ideal robotic application.
Display loads – Display loads frequently require four-way, labels-out orientation, multiple sheets within a single load, special dunnage, etc. While it is possible to address these requirements with a conventional palletizer, a robotic palletizer is a more practical, cost-effective solution.
Conventional palletizing applications
Conventional automatic palletizers are capable of very high speeds, and are routinely specified for high-speed manufacturing lines found in the food, beverage, and consumer goods industries.
High-speed – 200 cases per minute and 20 layers per minute are possible on in-line, continuous-motion palletizers. Since robots are intermittent motion machines, it would take many of them working together to achieve these speeds. For high-speed manufacturing operations, no other alternative can match the speed of conventional automatic in-line palletizers.
Reduced product packaging – Robots pick and place products, while conventional palletizers convey products into position. Since they never pick up the product, conventional palletizers are more tolerant of packaging changes. One conventional palletizer can handle cases, trays, film bundles, polybags, etc.
Complex pattern forming – Because conventional palletizers can handle each case individually, pattern changes have a small impact on rate. To get reasonable throughput from a limited cycle rate, robots handle multiple cases at a time. If case sizes or stacking patterns change, dramatic rate reductions can result. For example, changing from a nine-block, column-stacked pattern to a nine-block pinwheel pattern often will result in a 50% rate reduction on a robotic system.
Hybrid motion control palletizers combine articulated-arm robots with conventional palletizers, yielding a solution with the flexibility and repeatability of robotic arms with the speed and reliability of conventional palletizers. Hybrids are ideal for reduced secondary packaging applications that require gentle handling and high throughput rates.
Robotic pattern forming with conventional layer deposit – This concept combines the best of both technologies for high-rate applications. Robots are used to precisely turn and position the cases, while conventional technology is used to square and deposit the layers. Because the robot does not have to lift the product, it can operate at more than 40 cycles per minute on a wide range of package types. Because cases do not have to be positioned in fixed-lane locations, pattern flexibility is improved and new pattern creation is simplified. The cost for this concept is higher than stand-alone conventional high-speed palletizers, but the added expense can be justified in applications that demand a high throughput rate with small packages arranged in complex patterns.
Recommended: Modular systems, future flexibility
Hybrid applications, which use robots as components of a machine, are experiencing a growth in adoption as advanced processes like mixed-load palletizing become automated. As mass production lowers robot costs and breakthroughs in technology enhance the speed and quality of packaging lines, more applications, such as stabilizing tier sheets insertion, will be performed robotically.
Equipment enhancements and add-ons, such as updated end-of-arm tooling, additional robotic arms, as well as slip-sheet and pallet placement equipment, can increase palletizing speed. Furthermore, easily integrated modules and customizable end-of-arm tooling enable savvy operations to ship robotic arms and associated subsystems to other manufacturing facilities for continued service, a far less costly solution than purchasing new equipment.
Whether it’s conventional, robotic, or hybrid, constructing a modular solution ensures that systems can scale with an operation, handle evolving packaging styles, and be redeployed to alternate production lines. Reconfiguring, re-scaling, and redeploying industrial palletizing robots and automation can help operations exceed planned payback and ROI parameters, while meeting the evolving automation demands of growing operations.
– Earl Wohlrab is palletizing and robotics systems product manager, Intelligrated. Edited by Mark T. Hoske, content manager, CFE Media, Control Engineering and Plant Engineering, firstname.lastname@example.org.
Modular motion controls for conventional, robotic, or hybrid applications help maximize return on investment and assist with:
- Scaling of systems as an application grows
- Adapting to evolving packaging styles
- Easier reuse on alternate production lines.
How can industrial palletizing robots and automation help operations exceed planned payback estimates?