Control architecture enhances machine innovation

Hensen Packaging Concept GmbH (HPC) (www.hpc-machines.com), Bremen, Germany, has more than 25 years of experience building advanced packaging machinery. Advanced, yet easy-to-use control systems made possible by Rockwell Automation's (www.rockwell.com) Integrated Architecture approach have been key in developing the advanced packaging machinery that keeps these innovations coming.

HPC is best known for its filling and sealing machinery, offering a range of standard and specialty machines to suit a wide range of applications. It specializes in machines designed to fill and seal standup cartons and pouches, a sector that is moving from the humble role of refill packs to highly innovative consumer goods. The company also builds machines to form cartons and assemble finished products in their final packaging, enabling it to offer complete end-to-end packaging systems. Hensen machines are designed to be flexible and easy to maintain, to operate reliably at high throughputs and to enable rapid product changeovers.

Rockwell Automation has supplied automation and controls to many companies featured in Packaging Digest stories. For a list of these stories, go to the Packaging Digest website at www.packagingdigest.com

HPC's customers in the highly competitive world of fast-moving consumer goods are constantly looking to develop new products to catch the jaded eyes of shoppers in supermarkets the world over. In Germany, standup cartons and pouches are mainly used as refill packs, but in North America and the Far East, manufacturers are now using standup pouches with resealable tops to package liquids such as energy and sport drinks, laundry detergents and personal-care products. In the sports-drink sector, these work particularly well as alternatives to plastic bottles or cans, as the curvaceous pouch, with its molded hand grips, looks different on the shelf and enables thirsty sportsmen and women to gulp down the refreshing liquid faster. Today's high-speed, fully automated packaging machines require state-of-the-art control hardware and software, including accurate motion control, easy-to-use human machine interfaces (HMIs) and powerful logic control.

As a major exporter to customers around the globe, HPC needed a well-recognized automation supplier able to provide first-class, global, technical support and parts backup. The company also wanted to work with proven experts in advanced automation, able to bring their knowledge and experience to help develop sophisticated controls for HPC's next-generation packaging systems.

After carefully considering a number of automation vendors, HPC selected Rockwell Automation and has standardized on the Allen-Bradley Logix automation platform for its latest packaging machines. Logix is a family of PLCs, ranging from the powerful ControlLogix to the compact FlexLogix distributed controller. With such a wide selection available in the Logix range, HPC always has the right controller to match the application, from the smallest machine to the largest production system. Because all Allen-Bradley PLCs share the same Logix control engine, they are programmed using the same easy-to-use RSLogix5000 software, so HPC's engineers only need to be familiar with one development tool. Code can be reused across the range of controllers.

ControlLogix brings together logic and motion control in a single, integrated architecture, and both can be programmed easily via RSLogix5000 using a common set of tools. In addition to this common development environment, the Logix family also takes advantage of NetLinx, a unique Allen-Bradley network protocol with open software interfaces that ensures the efficient flow of data. With NetLinx, data can be sent just as easily over DeviceNet, ControlNet or EtherNet/IP and, because these networks use the open CIP Internet protocol, they also link directly to a manufacturer's enterprise resource planning or other business IT systems.

By ensuring completely transparent communications, NetLinx also enables configuration of the complete machine from a single point of access. Because the engineer can program devices remotely over the network rather than having to physically connect to each one separately, commissioning time is greatly reduced.

Similarly, the maintenance engineer is able to diagnose and correct many problems from the control room without having to go to the machine. Internet technology takes this concept a step further and, by installing an Allen-Bradley 9300-Rades Ethernet modem, users can have remote dial-in access to an entire NetLinx-based control network from a PC anywhere in the world.

NetLinx is one of the keys to Rockwell Automation's Integrated Architecture approach, which means that all of its hardware and software work together seamlessly off-the-shelf. Integrated Architecture offers many benefits to machine builders like HPC, as it dramatically reduces the time taken to design and build control systems. It also improves the performance, maintainability and reliability of the complete machine, increasing the productivity and profitability of the manufacturer.

Another benefit of using DeviceNet with the Allen-Bradley platform is Automatic Device Replacement (ADR). ADR enables devices such as Allen-Bradley PowerFlex drives to be replaced in minutes without shutting down the network, which minimizesing downtime in the rare case of a breakdown.

To communicate information between the controller and servo drives, ControlLogix uses the SERCOS digital interface and high-speed fiber-optic network. The network replaces the complex bundle of wiring associated with traditional servo drives, and it is also used to send and receive information about the status of the drive. The benefits of using SERCOS include ease of commissioning, higher accuracy and improved system performance.

HPC has also standardized on Rockwell Automation's Allen-Bradley Guardmaster machine-safety systems. With a complete selection of safety products, ranging from simple interlocks to screening systems using laser scanners and light curtains, Guardmaster meets all of HPC's safety requirements, while guaranteeing compatibility with the Allen-Bradley control architecture.

The benefits of Rockwell Automation's Integrated Architecture are demonstrated in HPC's latest packaging machine, the HO-Auto. This fully automated machine uses an integrated system of motion and logic control to insert and seal a spout into a carton.

The ControlLogix controller enables the machine to be rapidly changed from one carton size or format to another, increasing the flexibility and productivity of the machine. The time required to change tools to allow different size spouts to be inserted in the machine has been dramatically reduced compared with conventional machines. This has been achieved by using servo drives to reposition key components within the machine according to instructions sent by the PLC via DeviceNet.

An Allen-Bradley PanelView HMI allows the operator to select the machine configuration required, and ControlLogix does the rest. Control of hydraulic valves and feedback from sensors is via Allen-Bradley Flex I/O modules distributed around the machine and linked to the PLC by DeviceNet, reducing the amount of wiring required to be brought back to the control panel. Once completed, the cartons can be delivered to the next stage of production either by conveyor belt or on rails.

HPC also relies on Rockwell Automation motion control for its CMF range of flexible filling and sealing machines. These continuous machines can handle up to 250 cartons/min, which are supplied via a system of rails or direct from an HO-Auto carton-forming machine. The cartons are fed into the CMF by a patented indexing system and are are guided to the filler.

Here they are loaded onto a carousel, where 12 stations fill and seal the cartons. A security seal can also be applied at this stage if required.

Each filling station on the CMF's carousel uses an Allen-Bradley MP Series low-inertia servo motor controlled by an Allen-Bradley Ultra3000 digital servo drive. Offering high torque-to-size ratios, the MP Series motors take up a minimum of space and are easy to install on the carousel. The Ultra3000 drives are also mounted on the carousel and are linked to the ControlLogix PLC via SERCOS interfaces. Slip rings connect the moving carousel to the rest of the machine, allowing DeviceNet and SERCOS networks to operate seamlessly across the rotating joint.

The filled and sealed cartons are transported to thefinal packaging stage on a conveyor belt controlled by a PowerFlex variable-speed drive.

"The excellent levels of integration achieved between networks and the servo technology with Logix reduces engineering time considerably," says HPC's programmer, Jorg von Mallotkie. "This is due to the ability to undertake all configurations of the machine from a single point using one piece of software. Diagnosis of problems during commissioning is also possible from the same single-point interface, enabling us to install and commission the machine far more quickly than before."

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