Chewing Gum Maker Vertically Integrates Manufacturing Process for Increased Production
Denmark-based Dandy Chewing Gum produces more than 30,000 tons of chewing gum each year. The company's annual production has doubled in the past two years, just to meet market demand. One of the reasons that Dandy has been able to increase its output so dramatically is that they have vertically integrated the manufacture of key ingredients such as gum base and are more fully automating their batch processes for making many different gum brands.
"Our need for automated production systems was caused in large part by the overwhelming success of our sugar-free chewing gums products, which require more gum base than standard sugar-sweetened gum," explained Torben Schwartz, project engineering manager. "Our variety of gum brands was also expanding, with new medicinal gum products that dispense carbamide tooth decay protection or nicotine dosages via the chewing gum."
The automation project began in February of 1995. It was targeted specifically at replacing an aging gum base production department, which was quite small in size, with an entire new building that would have the capacity to meet Dandy production requirements for years to come. At the same time, project engineers launched a three-phase program for optimizing all plant operations, choosing the Wonderware Factory Suite of application development software tools, from Wonderware Corporation (Irvine, CA) as the means to implement much of the automation effort.
About Dandy
Nearly 95% of the company's gum products are manufactured at the main plant in the fjord city of Vejle, on the eastern coast of the Jutland peninsula in Denmark. A packaging plant in Russia is responsible for taking gum produced in Vejle and packing it for that marketplace. With annual revenues exceeding 1.6 billion Danish Kroners (about U.S. $286 million), more than 97% of the company's gum output is exported.
The process used to make the gum base involves granulation of rubber materials from bulk powders. The ingredients are weighed and batched, then pelletized in an underwater pelletizing system manufactured by Gala/Xantec, a German machine builder. The finished pellets are shipped in bulk containers to the gum making plant up the road where they become the principal ingredient in all Dandy chewing gum brands. Dandy uses a "dragee" process - in which the gum base is coated with sugar or other flavored sweetener - to make chiclets, rather than sticks of gum.
"The Xantec machines use the Wonderware InTouch human-machine interface (HMI) software as their machine control system and that is where we first saw these highly graphical displays that could be used to replace hardwired buttons, switches and indicators," Schwartz explained. "We liked the software so much we decided to use it as the primary supervisory control and data acquisition (SCADA) system for our plant."
The Dandy engineering staff enlisted a number of suppliers to assist in designing and implementing the factory upgrade. They used the AN Group, a Danish system integrator, to help with project analysis and software design. Installation was managed with the help of Kjaergård EL. Wonderware distributor Industrial Communication Denmark sold Dandy the InTouch software and advised on its use.
"We began the project with a very thorough analysis of how information flowed through the factory so that we could better describe all of the operator commands and actions that would need to be taken," Schwartz said. "We then referenced that data flow information to the system solutions. The system was so well designed that it was correct from the start - we didn't have to make a lot of changes after it was installed."
The resulting automation solution is an object-oriented system. Each data point in the factory has its own tag name identifier for the database. Siemens S5 programmable logic controllers (PLCs) are used as the primary control devices, using modular sequenced PLC programming. InTouch was used as the standard interface for all production machines so that no matter which machines operators are running, they have the same functionality. "The installation was done in three phases," Schwartz said. "It began with automation of all machine operations, in 1996. The second phase, implemented in 1997, involved horizontal integration, in which we optimized all activities to smooth the data flow through the plant, and set up real-time data systems for managing material flow. The third phase, also done in 1997, included integration of these factory systems with our AS/400 system at corporate headquarters. All were linked to monitor consumption of raw material stocks and finished goods management."
Integrated Batch & Production Systems
The initial automation phase created in 1996 manages the batching of bulk materials and pelletizing of ingredients into gum base. Phillips weighing controllers measure precise amounts of rubber ingredients for each batch of gum base. Each Pepperell + Fuchs material container used to transport ingredients through the plant has its own individual electronic brick code tag. The tags are read by Datalogic bar code scanners as the containers move around the plant floor, so ID and lot numbers can be tracked for product geneaology. Six Siemens S5 135-U Series programmable logic controllers (PLCs) are linked in an H1 network to control the batching and production operations.
"We have nine InTouch stations we use to run this plant; there are no manual controls anywhere," Schwartz said. "We have one master node and a system development workstation, plus one station each for the ingredient insertion and granulating systems, one for ingredient weighing and batching, one for mixing, one for the pelletizing machines, one for the outlet end of the plant and one for the power plant and environmental systems.
"We have two NetDDE servers that manage data communications among the PC and PLC networks, using the Siemens 3964R protocol for the PLCs and RS-422 for the PC connections," he continued. "This provides us with a backup capability should we have a failure on either network, but we have not had to use it much. The total system presently consists of about 150 operator screens and about 6,500 data tagnames.
"This system runs 24 hours a day, seven days a week, and one of the greatest benefits has been that it provides a common user interface for all of our different equipment," Schwartz explained. "The system looks the same to all of our operators, regardless of which application they're running. It's easy to maintain and enhance different systems also, using a single graphical user interface (GUI). We can identify problems faster and can optimize production more effectively because we have so much better control of it. Each operator has a unique identification associated with his or her name so all they have to do is sign on to the system and they're authorized for any tasks that they need to perform.
"Our operators like the system, so they've adopted it easily," he added. "People have had to change their way of thinking about our production systems because they came from a completely manual way of doing things. But the benefits have outweighed any reluctance to use the new system. Our people like the highly graphical way data is presented because it's more intuitive for running the operations."
Although the operator interface graphics for the Xantec pelletizer machines were done by the machine manufacturer, Dandy staff and the AN Group systems integrators took the same approach for creating flexible screen designs. As one example, the historical trend charts clever graphics of actual "pens" for data display. Operators can select whatever tags they want to display and click on a button to have the system plot the trends accordingly. Now that the Dandy staff is familiar with screen creation the plan is to create graphics standards that can be distributed on diskettes so that no matter who designs InTouch screens, they will all have the same look, feel and level of detail.
Some of the Dandy staff have enjoyed the changeover more than others. The new systems are used to provide remote services that were not possible previously. "Our primary maintenance person lives a long way from the plant and he really enjoys being able to dial in on a laptop computer and see the whole factory," Schwartz said. "He now has the ability to resolve problems from home, which has saved him travel time at odd hours. The only thing he can't do is manual ingredient adds - and as soon as we automate that, that will be possible, too."
Future System Replication
The automated production systems at Dandy have allowed the company to double its production capacity in only two years and the company is planning on similar increases being required to meet future demand. A major new market has been created in Russia since the opening of that country and eastern Europe. "We set up a packaging plant to meet demand in the Russian market, but we're now doing a study to see what sort of plant we can build to perhaps handle the entire production process there. We estimate it could be as large as a $100 million investment for us, but we know that we would use similar automation systems there if we build the plant," Schwartz said.
InTouch Specifications:
• Hardware Required: Runs on any machine that will support Microsoft Windows 95 or Windows NT 4.0 workstation
• Software Required: MS Windows 95 or NT 4.0
• Networking: Supports any standard NetBIOS network: Ethernet, Novell, Token Ring, Arcnet, etc. DECnet, Serial and TCP/IP connectivity supported.
Wonderware Corporation, a unit of the Siebe Control Systems Group, was established in 1987 to develop and market human-machine interface (HMI) software products for use on IBM PC and compatible computers in industrial and process automation applications.
In 1997, the company offered its entire product line as a single toolset called the Wonderware FactorySuite. This cost-effective bundle of products was modeled on the concept of the Microsoft Office suite of office automation programs. It provided industry's first integrated set of application programs for developing most any application in manufacturing, continuous process and batch industries.
For more information contact: Wonderware Corp., 100 Technology Drive, Irvine, CA 92618. Tel: 949-727-3200; Fax: 949-727-3270.