Automating a Confectionery Packaging Machine
Chocolate products place heavy demands on packaging machine manufacturers. Speed and flexibility need to be combined with gentle handling. The Italian company Fima specialises in the packaging of confectionery products. To make sure that the machines "stay in time" and that the individual modules are perfectly synchronized, the company uses Pilz motion control; not only does it control the automation and drives reliably and flexibly, it's easy to handle too.
Ever decreasing loads, frequent product changes and rapid time-to-market - these are the challenges that chocolate product manufacturers face. Fima, which is based in Bologna, belongs to the OPM Group and is famous for its innovative packaging machines, predominantly for the confectionery industry. Although the company operates internationally, it sells most of its machines into Germany, for that's where there is a huge demand for gentle product handling and a high level of flexibility.
Modular concept for packaging chocolates
Fima's "Sweet Magic HF" (Hollow Figures) wrapping machine can handle several different wrapping styles for chocolate pralines - from envelope style to single and double twist wrapping, through to hollow figure wrapping.
The machine has a belt conveyor with ready-made molds corresponding to the product to be wrapped; it also has an integrated, automatic product infeed.
Like all Fima's machines it has a modular design, in other words, it can be broken down into functional blocks, made up of individual modules or an electromechanical component.
o The "infeed" module consists of a belt conveyor containing product-specific molds, which feeds the products on to the turntable.
o Paper handling: Electromechanical component to unwind, cut and position the foil on the product
o Turntable: Carousel with eight stations, which divides the folding processes into individual steps. Each folding step is undertaken by a specific wrapping module;
o Wrapping module: Each of these modules performs a specific wrapping step;
o Belt module: Used for products that have additional braiding;
o Pick and place: Feeds the machine. The products are picked from a transport plate and placed on the belt conveyor. The products are picked up using suction caps.
Special configuration features
The various modules are very easily accessible for a rapid format change. This is also an advantage for the machine's maintenance and cleaning requirements, particularly in view of the fact that all the modules are self supporting, i.e. dirt drops off as soon as the module is removed.
To switch the format, or the product, all the operator has to do is exchange the wrapping module for the respective packaging type, the product-specific belt conveyor and the turntable. The remaining adjustments for the new format are made automatically when switching to a new recipe.
All the servo motors are linked to the movement of the turntable via electrical cams. The cams are defined via the stored recipes, and all the machine's movements are finely coordinated in the process. All the adjustments for new products result from the recipe selection made on the operator terminal. The pick-and-place station is not a separate part of the machine, as is often the case, but receives the data from the same recipe data set. This means it's possible to undergo a complete format or product change in around 30 minutes, including all the mechanical modifications.
Particular attention was paid to special functions on the machine, to counteract material waste. Thanks to the "No product, no packing material" function, the wrapping material is only unwound and drawn into the machine when the product is actually present.
High-level performance
The machine's flexibility was achieved thanks to the versatility of the motion control system PMCprimo Drive, which is employed in these machines. This enables the operator to optimize the synchronization of the individual axes at any time.
The "Sweet Magic HF" uses five Pilz servo motors, which are automated via the drive-integrated control system PMCprimo Drive. As no space is required for a separate controller, it's also possible to save space in the control cabinet. With the development of the PMCprimo Drive it was finally possible to meet the various requirements of the packaging machine manufacturers. Fima in particular was able to increase the efficiency of its machines demonstrably. Optimum packaging is achieved thanks to the ability to detect the exact position of both the product and the wrapping material.
Also, the control system can react quickly to changes by optimizing a series of pre-defined parameters.
In terms of the software, all functions are implemented using ready-made program modules in accordance with IEC61131-3; all that's needed is to set the parameters. So the programming of complex functions is reduced to a minimum. Another feature of the control system that Fima values very highly is the ability to use all the digital outputs on the PMCprimo Drive as digital cams. This means that the status of the outputs depends on the respective axis position. So fast reaction times are guaranteed and the solenoid valves in the machine are reliably controlled.
Both Pilz and Fima are convinced that they have taken the right course in terms of satisfying the rapid changes in market requirements. This can be achieved through machines with minimum set-up times, which guarantee high plant availability. Not forgetting the flexibility of a modern machine, which enables an immediate reaction to trends and special requests.
Pilz has been a motion control partner of Fima for many years; with the PMC product series (Pilz Motion Control) and all its possibilities, it has contributed to the success that the packaging machines have enjoyed.
Solutions for the packaging industry
Pilz combines the issues of safety, automation and motion control. From sensor technology and the corresponding evaluation devices with diagnostics and visualization, through to actuator technology: Pilz can implement universal solutions. The packaging sector is keen to increase quantities and the number of product types. This is where Pilz can point to new horizons. Many Pilz products are designed to meet the specific needs of the industry. For example, PSEN safety switches take into account the industry's strict hygiene requirements by being resistant to cleaning agents. The range of PMI operator terminals also includes units with approval to be used in flammable and explosive environments. Excellent recipe management is also provided, so that rapid format changes can be supported.
Pilz is a global company, as such, not all standards and information will be applicable worldwide. Please check with your local Pilz office to ensure your factory and/or machines meet local standards.
