PC-based Control, Robotics Help Packaging
PakTech sells handle application machine systems, manufactures plastic handles for multicontainer packages, and makes tooling equipment to mold the handles that its machines apply. PakTech machines can serve most applications in the packaging industry for the bundling of products. Examples include beverage bottles, spray bottles, lawn fertilizer containers, and personal care products. PakTech also integrates its systems with those of container manufacturers to add handles to containers before filling.
Cost of PLC control
“During the process of developing a new control system, we required a control solution that wasn’t as restrictive and tightly packaged as our previous solution,” said Dan Shook, director of operations, PakTech. “We also sought a user interface specific to our type of equipment so that the look and feel would be the same across different PakTech platforms.” Previously, a large PLC manufacturer also provided touch panels and “proprietary software to create push button interfaces, etc. In addition, we wanted to develop more brand-specific look and feel to PakTech application machinery.”
PakTech began a redesign of its handle application machinery starting with the MPA60 model. This “multipurpose applicator” machine can apply handles at 60 cases per minute. The machine integrates a Fanuc robot arm so that the user doesn’t have to be heavily trained in robot programming.
PakTech installs the machines. “Essentially all the customer has to do is select the product by hitting the start button,” Shook said.
Speed and affordability are essential. “We needed to bring down our controls costs to find a better balance of performance and price,” Shook noted. “Our competitors’ machines are often are stuck in the 25-case-per-minute range with a lower quality die-cut handle. Their answer to ‘more speed’ is by adding more machines that are operated in parallel—this is simply not sustainable if you want to control your plant floor utilization and machine footprint.”
For one competitor to get a “50-case-per-minute machine,” it offers “two low-performance machines at $120,000. The base PakTech model with the previous major brand PLC cost $200,000 or more,” Shook said. “We needed to expand our control ability while reducing our costs, which we couldn’t do with a separate servo platform and PLC platform.” The prior vendor’s control system with components costs at least $50,000, “a serious threat to our competitiveness and sustainability.”
The original equipment manufacturer (OEM) needed fewer layers of engineering.
PakTech had several years of PC-based control experience with Husky injection molding machinery, used to manufacture plastic handles. That solution offered easier programming and Ethernet communications for easier robotic integration and better remote connectivity, via the Internet to reduce support expenses.
“Having an industrial PC installed on the machine is a critical component to best-in-class remote connectivity,” Shook said.
PakTech systems typically integrate with a conveyor and receive products upstream. Sensing when the products are present, PakTech machines control the sequence to a particular location using a Fanuc robot to apply handles via pick-and-place. PakTech systems check if the handles were applied correctly, and then the products move downstream for further packaging steps. The system also communicates line speed to other plant systems, such as enterprise resource planning (ERP) software. PC-based control facilitates remote maintenance with easier HMI and robotic connections than using a traditional PLC, PakTech said.
The MPA60 from PakTech uses a PC-based automation and motion control system with an embedded PC with Intel Celeron M ULV, 1 GHz processor or industrial PC with Intel Core Duo, control panel, motion control software, and HMI. For communications, the MPA60 uses IP67 EtherCAT I/O modules for mounting outside cabinets in harsh environments. The motion system includes servo drives (used as variable frequency drives: VFDs) and servo motors, also communicating with EtherCAT.
The small embedded PC measures roughly 6-in. W x 4.5-in. H x 4-in. D in PakTech’s configuration, and it provides a direct backplane connection to the I/O terminals. The software helps transition to IEC 61131-3 structured text (ST) programming, still using ladder logic (LL), when needed.
“We prefer to utilize function blocks, structured text, and the programs created in C+ in a way that’s in the background from the customer’s perspective and lockable. This goes a long way to protect PakTech’s intellectual property and enhances flexibility.” PakTech systems include one-touch operation, easy-to-set-up controls, and tool-less changeovers, eliminating time-consuming and costly efforts to modify and debug PLC code for customers.
“Breaking through the old way of designing packaging systems in North America while maintaining customer trust is vitally important for us,” Shook said.
For the I/O and information exchange on the robots and vision system, PakTech must also have networking infrastructure to accommodate Profibus and EtherNet/IP. For teaching the robot and vision system, PakTech has implemented a user-friendly Web-browser system over the EtherNet/IP connection. The previous control system required the user to connect with a laptop computer, establish an IP connection, and navigate to a main screen with the controller, which “required too much training and documentation to be a workable solution,” Shook recalled. With the selected “PC-based control architecture, we’ve implemented a simple push button on the machine that opens the interface to teach the robot and vision system—it’s exceptionally simple by comparison.”
The machine-mountable I/O solution enabled PakTech to meet the requirements for high-performance networking and data acquisition in the field to various areas of the machines. “In the past, all our I/O was centralized, and we had a great deal of wiring back and forth to the field.” The new system reduces wiring and the related costs and time required, Shook said.
Using EtherCAT as a drive bus “further consolidated the panel because we now have two motor outputs with every drive,” Shook noted. “We were previously using a dedicated VFD, and those were fairly large units, taking up a large amount of cabinet space by comparison.
“We needed to implement motion control flexibly without having an automation platform that was overloaded with unnecessary controllers. For instance, our previous control technology involved a PLC and a separate motion controller communicating via SERCOS. PakTech has successfully consolidated these components—with EtherCAT and PC-based control we can implement the motion and logic in the same controller,” saving space.
The new system “cut our required training time in half for our customers” because of less time to train the plant maintenance technician on how to navigate through the previous system.
PakTech also gained the ability to interact with the machine platform over a remote connection versus logging into one component at a time as with the previous control architecture.
“We’re confident we’ll maintain 99% efficiency with installed machines, and we’re expecting a 20% improvement in reliability over our previous design. Today we have 20% more control cabinet space to accommodate additional hardware requests from customers.” The switch also is expected to reduce the panel-build by 8 hours. PakTech gained ability to scale up to full servo functionality without buying anything extra, and “we’re paying about the same amount as our previous vendor’s VFD that provided zero servo capability,” Shook said. Savings is about $3,000 per servo axis.
Also, there’s no need for yearly run time licenses. A new high-performance machine (the CCA2400) “will apply the closed top rings at an extremely fast rate of 2,400 cans per minute—to keep up with this speed.”
PakTech control engineers expect to continue to introduce the system as the standard platform across all machine lines.
PakTech container handles
Product packaging serves a variety of obvious purposes, including point-of-purchase advertising, content information, product protection, and ensuring freshness—but a purpose considered perhaps less frequently is the easier organization and transport of packaged goods. A key component in this area of packaging is the multipack handle. In 1992, Jim Borg, founder of Eugene, Ore.-based PakTech, designed the TwinPak handle to accommodate a pair of gallon-sized milk containers, and the rest, they say, is handle history.
Today PakTech makes handles to unitize 2 to 12 containers as well as the UniPak bale handle for carrying large, single bottles. PakTech also makes machinery to apply handles in-line at almost any speed necessary. PakTech also offers in-house products and services that can be hard to find, including: part design and engineering, mold development, injection molding manufacturing, UPC label application, as well as the design, manufacture, and service of in-line application equipment.
Typically, PakTech customers initiate a new project because they require a new multipack handle design. PakTech gets a clear idea of the customer’s project and provides a 3-D image of the handle within a week to begin a prototype. PakTech can easily provide injection molded samples within two weeks, helping PakTech remain competitive, adapt to changing requirements, and quickly bring new products to market. The company also recently released a new multipack solution for the canned beverage market, applying new proprietary PakTech plastic handles for 6- and 4-can soda and beer packs. These plastic handles cover the tops of cans, allowing them to remain 95% to 98% cleaner (based on recently completed third-party testing) than those with standard “rings.” PakTech plastic handles also are 100% recyclable. The new machine is expected to use PC-based controls from Beckhoff Automation.
Beckhoff’s brand of PC-based control technology is used in the Husky and PakTech machines, according to Dan Shook, director of operations, PakTech.
MPA60 from PakTech uses a Beckhoff automation and motion control system comprising a CX1020 embedded PC with Intel Celeron M ULV, 1 GHz processor, or C6920 industrial PC with Intel Core Duo, CP6201 control panel, TwinCAT NC PTP software and TwinCAT PLC HMI.
For communication, the MPA60 has EtherCAT Terminal I/O, EtherCAT Box modules for IP67-rated I/O for mounting outside cabinets in harsh environments. The motion system includes Beckhoff AX5000 EtherCAT servo drives (used as VFDs) and AM3052 series servo motors.
The CX1020 embedded PC measures roughly 6 x 4.5 x 4 inches (W x H x D) in PakTech’s configuration connecting directly to Beckhoff I/O terminals.
TwinCAT NC PTP helps customers migrate to structured text (ST). “We’re using TwinCAT’s ability to work with ladder logic so we can make code that looks like what some of our customers are used to when necessary. We prefer function blocks, structured text, and the programs created in C+ in a way that’s in the background from the customer’s perspective and lockable. This goes a long way to protect PakTech’s intellectual property and enhances flexibility,” Shook said.
Beckhoff AX5000 can scale up to full servo functionality without buying anything extra, and “we’re paying about the same amount as our previous vendor’s VFD that provided zero servo capability,” Shook noted, saving up to $3,000 per axis.
“With Beckhoff, we buy the license once and all updates are free, regardless of how old the license is,” Shook explained.
– Shane Novacek is marketing communications manager, Beckhoff Automation LLC. Edited by Mark T. Hoske, CFE Media, Control Engineering, www.controleng.com.