Learn more about food production packaging! Regional sales manager, Derek Williams, talks about how Brenton ensures food items are handled and packaged with the utmost care. Featuring information on washdown, end of arm tooling, vision, and cold room packaging solutions.
As a consumer, nearly every physical object you use on a day-to-day basis was, at some point, loaded on a pallet. Pallets are the simple, structural foundations used to ship loads of product all over the world. They are the commodities on which other commodities are shipped. Because pallets occupy such an integral part of our modern lives, they are among the most engineered and re-engineered products in existence.
Pallets are manufactured in various sizes for various applications. Many pallet standards exist, as do many organizations which set these standards. Some organizations are concerned with strength of materials, some with pallet dimensions, some within specific industries, and so on. ISO sanctions six pallets, the most common of which in North America has dimensions of 40” x 48” (typically 5-6” in height). These pallets fit well in a standard ISO 40’ shipping container. In other parts of the world, like Europe, one will come across metrics pallets with similar, but different, dimensions as those in North America. Different shipping containers are sometimes used to maximize the load capacity with matric pallets.
Most commonly manufactured from wood, these pallets typically use industrial grade lumber in contrast to high grade (commonly known as ‘grade’) lumber like that used in construction, flooring, and furniture. (The industrial lumber comes from the parts of the tree which cannot be used as grade lumber.) Plastic pallets are the second most common type. In general, plastic pallets can be reused more times than wood pallets and are well-suited for applications requiring a high degree of sanitization. For these benefits, among others, plastic pallets often come at a premium over wood pallets.
The two most common designs for wood pallets are called stringer pallets and block pallets. Stringer pallets use boards (or ‘stringers’) to support the top deck boards. Block pallets, as the name implies, commonly use nine blocks to support the top deck boards. In many cases, stringer pallets are ‘two-way’ pallets which can be accessed by fork trucks and pallet jacks from two sides; whereas block pallets are ‘four-way’ pallets which can be accessed from all four sides. There are exceptions to this rule, however, and one could find hundreds of detailed articles evaluating the two types.
As factory automation has become more widespread, so has the automatic loading of product on pallets. The most typical object automatically loaded on a pallet is some sort of secondary package like a box, bag, or drum. Within the consumer goods industry, the most common secondary package is a corrugate shipping case or tray. Most automatic pallet loaders (‘palletizers’) in this industry are designed to handle corrugate cases or corrugate trays.
Conventional palletizers typically use a series of conveyors, guides, and pneumatic actuators to position and orient cases in the desired array which is equal to one layer in the unit load. The layer is then placed onto the pallet by a combination of a tray to support the layer and an elevator (sometimes the layer is elevated and sometimes the pallet is elevated). These types of palletizers can reach high speeds and have the flexibility to be changed from one product/load configuration to another. The reverse of this process can sometimes be used to de-palletize cases at the point of destination.
Robotic palletizers typically consist of a four or six-axis robotic arm integrated into a cell which picks individual cases, or a row of cases, and places them onto the pallet. The cases, pallets, and tier/slip sheets are often picked by the same end-of-arm tool installed on the robot arm. Robotic palletizers are well suited for medium and low speed applications, and applications where multiple products must be palletized at the same time, in the same cell. Robotic palletizers also have the capability of palletizing bulk product (not in cases) like empty bottles shipping to a fill line. Again, the reverse process of the robotic palletizing process can be used to depalletize loads.
When selecting a palletizer, one must consider the speed of the incoming product, the type of pallet, the load configuration, tier sheet/slip sheet requirements, the available floor space, the number of different product types (SKUs), and the size/shape of the products. There are many other factors to consider, but these are the basics used to select the type of palletizer. Automatic palletizers are often combined with an automatic stretch wrapper or automatic bander downstream in the product flow.
Every application is unique and requires a thorough review to ensure the best performing and most cost-effective palletizer is selected/designed. Please reach out to Brenton to discuss a specific application. Brenton has completed over 2,000 robotic and conventional palletizer installations, and our team is happy to use our experience to provide a trustworthy consultation. Learn more at https://www.brentonengineering.com/products/palletizing-systems/
There are countless benefits to robotics in packaging but one hang-up has always been the robotic teach pendent. This pendent is utilized to program and maneuver the robot including managing faults and jogging the machine. For someone who is well versed in robotics, a teach pendent is not an issue. However, once the machine is installed and running in a facility, operators need to have user friendly access to the machine. That is where robotic HMI interfacing comes into play. We are going to look at three benefits for integrating the robot with the HMI.
Single Point of Operation
The first benefit to interfacing with the robot through the HMI is having a single point of operation for the entire line. Operators are familiar with the HMI platform, navigating the teach pendent can prove cumbersome. Most lines are fully integrated to one HMI platform, allowing a single operator to run the entire system. When the robot is interfacing with the line’s HMI they can track the robot’s status, adjust application parameters, robotic positions and run programs all from a facility-familiar platform. To eliminate the operator’s need for the teach pendent allows them to run the entire line from a common HMI platform increasing OEE. This interface makes it easier to start, stop, troubleshoot and make adjustments to the robot (which we will discuss further, below) as well as the entire line.
Managing Faults and Changeover
As mentioned above, the HMI is a much more familiar platform than the teach pendent, simplifying the management of faults and changeover. Alarms and alarm history are echoed from the teach pendent to the HMI. The HMI allows operators to quickly diagnose the fault for shortened downtime. When jogging is required, overall layouts are displayed on the HMI. A more descriptive pattern for Changeover is another benefit received when interfacing with the HMI. Operators can pull information about the entire line and manage changeover and run time.
Display and Functionality
Finally, the most visually obvious benefit, the aesthetics of the HMI. As we move towards PC based HMIs, graphic display is impeccable, functioning much like our smart phones and tablets. Additionally, options available on the HMI such as language and layout, whether PC based or not, are greater than what is offered on the teach pendent.
The HMI will steal the show for much of day to day functionality, but, for now, the teach pendent will maintain its roll. The teach pendent still serves a primary purpose for the robot. Aside from initial set up, the teach pendent is also utilized during standard and preventative maintenance.
By Stephen Gandy, Applications Engineer, Brenton Engineering, part of the ProMach family of brands
End-of-arm tools (EOATs) for robotic palletizing come in all shapes, sizes, and price tags. Knowing what to look for in an EOAT speeds the specification process and leads to correct sizing and lowest overall cost. There are three basic categories of robotic EOATs for palletizing:
Before talking with the palletizing original equipment manufacturer (OEM) about the best EOAT, develop an accurate estimate of how fast cases will come down the line and what the average number of pallets per hour will be. Inflated case and pallet counts can lead to ordering a more expensive tool than needed, while counts that underestimate might result in an inadequate purchase, creating bottlenecks on the line.
For regular slotted cases (RSCs), test the top and bottom seal strength and make those measurements available to the OEM. No one wants ruined products splattered across the plant floor because tops or bottoms gave way due to too much weight. Provide a list of pack patterns required as patterns have an impact on the type of EOAT selected. Give the OEM sample cases and let its engineering team run tests, including the porosity of the corrugated board. Porosity impacts vacuum EOAT effectiveness.
There are two kinds of vacuum-based EOATs – Venturi and dense array. Venturi are ideal for lighter, yet sturdy RSCs weighing up to 30 pounds. Gripping one or two cases at a time, Venturi tools are idea for low to moderate speed palletizing and simple pack patterns. Venturi systems utilize the plant’s compressed air system, which means air hoses and air prep systems will have to be in place. Venturi systems are the least expensive of the options.
Dense array vacuum tools rely on a matrix of many small vacuum cups. Dense array tools have their own compressed air generator for greater air flow. Specifying a more powerful air system increases vacuum. Dense array tools are typically used on RSCs reaching up to 50 pounds. They can palletize multiple rows of cases per cycle. The matrix of vacuum cups supports variation in pack patterns with different combinations – zones – of cups programmed to operate during any given lift. Dense array tools are larger and carry a higher price tag than Venturi systems. Running larger pack patterns requires more equipment on the front end creating a pattern for the robot. This approach involves greater overall system footprint and cost.
Frequent cleaning of corrugated dust off the vacuum cups is part of routine maintenance. Occasionally, even with clean vacuum heads and a vacuum that is operating perfectly, cases simply fail to lift or detach from the tool. In these instances, determine whether the porosity of the corrugated board has changed. Another fact to be aware of is that high acceleration, of the robot, does not work well with vacuum tools. If high speed and acceleration are needed, then investigate clamp-based EOATs.
Clamp-based tools can be operated by either pneumatic actuators or servo electric actuators. One end of the clamp is stationary, while the other end moves in and out. Clamps lift by exerting side pressure, which means they can be used for packaging other than RSCs, including shrink-wrapped bundles such as cases of bottled water and display ready cases. Clamp-based systems allow the robot to accelerate faster than vacuum tools for higher overall speed. Servo-based clamps open and close faster than pneumatic-based clamps, but pneumatic clamps cost less. Work with the OEM to determine whether the speed differential is worth the uptick in price.
Pneumatic clamps are used when cases are all about the same size. Because servo systems can be programmed, they are better for applications where mixed sizes will be handled and for cases that require varying side pressures to hold the packaging without damaging it, for a gentle yet strong grip. Clamping tools require more overall space than vacuum. If the packaging in question will require bottom support during palletizing, then investigate fork-style tools.
Fork tools are utilized for packaging that requires bottom support and packaging such as bags or display cases for which neither vacuum or clamps may be suited. In addition to having a fork support the bottom of the load, these tools can also provide load stability with gentle support on the top and sides as well. Forks are the largest, heaviest, and priciest of the palletizing EOATs. They may also be the fastest as they can palletize multiple rows and can cycle many times a minute. Fork EOATs require the most space to operate, which may or may not be a problem, depending on the plant space available. Due to their weight and size, these tools may require a heftier robot than either vacuum or clamp EOATs, adding to cost.
Other than making sure that forks, clamps, and the robots themselves are properly lubed they are basically maintenance free. Complex pack patterns may not be suitable for clamps or forks. For complex patterns, a conventional palletizer may be the best option.
Work with OEMs that offer the full range of EOATs, including Venturi and dense array vacuum, pneumatic and servo clamping, and fork solutions. An OEM with limited solutions might push a particular EOAT regardless of whether it is the best fit.
For more information:
“This system isn’t where flexible automation is evolving, but rather where it has evolved.” Kevin Frye, Executive Director of Engineering, Ring Container Technologies
Kevin Frye’s quote says it all, Brenton’s small-footprint, hands-free case erecting, sealing, tumble packing, palletizing and stretch wrapping system is the standard for flexible automation. Brenton Engineering with its customer Ring Container Technologies recently had the opportunity to manufacture one of the most flexible and innovative hands-free end-of-line systems in the company’s history. The editors of Packaging World magazine featured the system in their August issue. We wanted you to have a chance to read it. If you have any questions about the approach let us know. Enjoy!
Please visit the link below to check out Brenton’s article on PackWorld.com.
Packaging World Jul 31, 2017