Thermoformers leverage advanced controls

For one maker of thermoforming equipment, servos have replaced hydraulics and pneumatics, while at another a new control system means nimbler equipment.

SencorpWhite used NPE 2018 May 7-11 in Orlando, FL, to introduce the Ultra 2, said to be the largest production steel rule die in-line thermoformer in the global plastics industry. On the machine, which has a footprint of 50’ x 11’, the process tonnage of 35 tons for form and 130 tons for trim is generated entirely by electric servo motors, and the steel rule die inline arrangement results in faster changeover and an overall cost only 10% of conventional punch & die systems, according to company sources. Onboard, 44 zones of heating are being controlled by a monitoring system supplied by Siemens, who also supplied the servos and other motion control components for this machine.

“The genesis of the Ultra 2,” says Brian Golden, Product Manager for Thermoformers at SencorpWhite, “was market analysis in which we determined a distinct need among our major industry segments for a more precise thermoformer with optimum control of form and trim operations, as well as a large forming area to increase production. The Ultra 2 boasts a 34-inch x 48-inch forming area. Typically, such a large machine would involve major challenges in motion and heat control, especially when running at higher production speeds.” That’s why the SencorpWhite engineering team, led by Greg Danti, turned for assistance to its longtime supplier Siemens.

“We were challenged from the outset, as SencorpWhite was looking for a faster thermoformer to do higher-end work,” says Siemens’ Hue Lieu, SencorpWhite Account Manager. “Likewise, they were seeking ways to achieve faster assembly, faster operation on the machine, overall cost reduction in various areas of heat and motion control, plus finally a greater throughput due to their newly designed steel rule die and proprietary off-loading system.” All of these things had to be addressed, says Lieu. “Just another day at the office, right?” he adds.

Overall, the Ultra 2 was in development approximately 21⁄2 years, with the bulk of the engineering focused on the electrical and electronic controls. “The Siemens team brought our unique TIA Portal to the table,” says Mathias Radziwill, Head of the Siemens Plastics Industry Group. “This system enables complete access to the entire suite of Siemens products and software available, allowing machine builders to engage in a totally digital enterprise during machine development, performance evaluations, simulation scenarios, build stages, and commissioning, plus it has full diagnostic and energy management tools. Many machinery builders view TIA Portal as their gateway to Industry 4.0.”

Servos are the key
The key to the machine form and trim tonnage was the implementation of electric servos. “It eliminated an array of mechanical components, with their obvious cost and assembly time expense for the customer,” says Lieu. “The servos also run the indexers on the rail system, which upped the productivity of the machine by 40% or so.”

SencorpWhite Director of Engineering Danti confirmed this fact. “With the industry trending towards higher-performance electric servos, we elected to move away from our previous reliance on pneumatics and hydraulic solutions for generating our tonnage.”

Siemens also assisted in the development of the proprietary off-loading system on the Ultra 2, introducing the SencorpWhite team to its Simotion D motion controller, which runs the system in 100% servo mode. Through the use of the Siemens Scout system, the machinery builder here was able to “test drive” a number of drives to select the optimum combination of features and price point. This new system utilizes stationary motors, driving the need for coordinated motion control. The Scout system provided the technical solution for this requirement.

Parts produced on the Ultra 2, given its combination of volume, speed, and accuracy, range from packaging used in the Health & Beauty Aids industry to medical packs to clamshells to various high-volume jobs where the increased number of parts per shot has tactical market advantages for customers.

In production, the inline steel rule dies allow faster changeover for the SencorpWhite customer. It’s hours, not days, according Danti. The original design called for electric motor drive. But Siemens’ Senior Accout Manager Lieu explains, “Servos were ideal for this application, and once we walked through the updated architecture with the guys, we all saw the light bulbs going off. The combination of less manufacturing time, fewer components, and the increase in speed with the desired accuracy won the day.”

On the HMI side, the selection of the Panel Pro IP67 gave the SencorpWhite team the optimum solution for a display that could withstand any anticipated working environment. As for heating control on the machine’s 44 temp zones, the choice was the Siplus HCS4300 control system, with detailed diagnostics that can detect internal faults in the load circuit, blown fuses, and defective heater cable. Network voltage and internal temperatures are also monitored per zone. The heating on the machine is radiated top and bottom, with individually controlled zones for form and trim. All communication is run over ASI Profinet, and CAT3 safety compliance is provided.

On the proprietary off-loading station, SencorpWhite achieves a 99.5% breakout of the web and the off-loader feeds a parts stacker via a specially designed five-axis servo and three-conveyor motion-handling system.

Golden concludes, “At the end of the day, we want our customers to have more good quality parts in the box, with less waste, less energy consumed, and a lot more profit in their pocket. That’s what we can offer them with the Ultra 2.”

Thermoforming machines for foam
The other maker of thermoforming equipment worth taking a look at is Commodore Technology. Recognizing in recent years that customers wanted shorter runs and more variety in order to keep pace with evolving consumer purchasing behavior, Commodore set out to create a new machine for thermoforming polystyrene foam trays and hinged-lid containers used for meats, baked, items, and deli foods. What they sought was a machine that would be more productive, more efficient, and faster to build. The first step to accomplishing this was to find a new control system that would help the company keep its long-standing promise of speed, efficiency, and value.

It was 2015 when Commodore began development on the machine it had in mind: the Model SX-28S Thermoformer. The firm partnered with Schneider Electric to develop a new servo-based control system that uses a Magelis G5U HMI, Lexium LXM52 servo drives, BMH motors, and PacDrive LMC101 and LMC201 controllers.

The primary goal was to increase cycles per minute at the forming station and the trim station. In addition, there was a desire to move to servo controls instead of hydraulic controls, because hydraulics could leak fluids, which were unacceptable in sanitary conditions like food processing. To take the equipment design to a new level, Commodore took advantage of servo drives and updated control technology.

Using the new servo-driven control system from Schneider Electric, the SX-28S thermoformer can perform up to 50 cycles per minute on forming and up to 175 cycles on trimming, a 70% increase compared to older machines.

The Magelis HMI has a 5.7 inch full-color touchscreen panel that promotes customization through simple software programming and gives operators intuitive controls that are easy to learn. The Magelis HMI provides more information so an operator can see and measure progress on the line.

“On the Magelis, our software specialist is able to do his job effortlessly,” says Kurt Bartosch, Engineering Manager at Commodore Technology. “It’s easy to train our customers because the controls are intuitive, and we can create a look and feel that matches other HMIs they use in the plant.”

The Lexium motors and drives were combined into a predefined servo bundle for easy integration and commissioning. Lexium bundles include standard interfaces, embedded safety function, and DC bus sharing.

The PacDrive controller has built-in templates and is synchronized with the entire system, so programming is done only once instead of separately on all servo drives, saving Commodore up to 15% on set-up.

Using an integrated solution with components provided by a single supplier has made it easier to order and to identify problems.

“With a fully integrated solution, there’s no finger-pointing during the troubleshooting process because the components are from the same place and are made to work with each other. It makes much more sense to have an integrated solution, which is why we chose Schneider Electric for all the control components,” says Bartosch.

Value is an important part of Commodore’s success. Measuring equipment as a capital cost per cycle, the SX-28S operates at $2,100 per cycle, while industry competitors cost up to $3,500 per cycle.

The SX-28S addresses concerns for many stakeholders at foam manufacturing companies. For the owner, the thermoformer performs better at a lower cost. For the operator, the machine’s speed keeps the line running and its interface is easier to use. For the maintenance technician, access to real-time diagnostics and worldwide technical support keeps things running smoothly.

For startup manufacturers or customers with high-variety, low-volume product runs, fast changeover is essential for maximizing uptime. The molds on the SX-28S can be easily changed, and because it’s a narrow web system the molds are half the price of a wider machine’s molds.

The SX-28S is a smart machine with built-in capabilities for open, secure access to devices and information. Combined with built-in diagnostic capabilities, the Schneider control system is especially helpful for maintenance and troubleshooting remotely.

Unique on-site feedback
By having its own on-site foam-products manufacturing operation, Commodore has access to immediate feedback on its own equipment. The plant uses 14 Commodore thermoformers and five Commodore extruders to produce up to one million pounds of a variety of foam products each month. Getting performance data in real time helps the equipment engineers see opportunities for improvement.

With the incorporation of the new Schneider Electric control system, the servo technology has helped Commodore make adjustments to its own foam package production. For 30 years, the company used 40 tons of loading pressure to make each foam tray. After implementing the Schneider Electric servo system, feedback from the system indicated that only nine tons of pressure were required—a change that not only saves energy, but ultimately extends the life of each machine. As a result, Commodore used this data in a decision to retrofit all of its older hydraulic machines to make them more efficient.

In order to prevent unforeseen machine downtime due to unexpected maintenance, Commodore has introduced proactive measures to educate customers on the importance of updating control technology before problems arise.

“It’s a constant effort to keep up with the evolution of technology and show customers how they can reach their greatest potential for success,” Hayward points out. “We strive to create the machine of the future, so we reach out to customers, make them aware of obsolete parts, and ask them to consider redesign and its performance improvements.”

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