Plug and Play: With zero-point clamping technology for the right pharmaceutical packaging
Without tools and with just thumb pressure, operators equip the robot arm with the suction gripper that fits the packaging cartons. That benefits security in packaging high-priced medications.
“That changing the suction plates without tools is so fast and easy surprised us and makes operating our packaging machines safer and even more efficient,” emphasises Christoph Rechner from pester pac automation GmbH. Through zero-point clamping modules with latching function from AMF, the lock of the format plates can be opened with mere thumb pressure, where earlier it had to be released through four screws in a cumbersome and time-consuming manner. Rainer Guggenmoos from AMF was sure right from the start that the zero-point clamping system would be convincing even in a completely unaccustomed area. These small power packets often fulfil other completely different tasks.
Zero-point clamping technology in a completely new application
The suction plates form the interface of the robot arm of the packaging machines between the cartons and the pharmaceutical products. They are tailored by the machine with vacuum technology in a product-specific way and ready to ship on pallets. Various suitable suction grippers are used, depending on the carton size. With a change in product or lot, precisely this mould part must be changed whenever the shape of the cardboard box changes.
That zero-point clamping modules are used here is new and completely unusual. For the ones found here are normally found in production or assembly environments, where they clamp fixtures, for example. For example, other modules of this series clamp workpieces in processing machines so that they can be cut. But Christoph Rechner and Rainer Guggenmoos had the idea and the courage to look beyond boundaries. And so in every laser-sintered, additively produced suction plate, two mechanical zero-point clamping modules from AMF (Andreas Maier GmbH & Co. KG) are used. They have a special locking function, through which they can be opened, locked in position, and remain in place by pressing a finger on the actuator knob. After a plate change, the next time pressed, the module is locked through spring force.
Packaging with tracking is the great challenge
Pester himself developed the optimal shape of the suction plates as part of a master’s thesis. As a 3D-printed format part, it weighs only a fraction of the earlier, screwed plates, which were made of aluminium or stainless steel. “With this project, we took several development steps at the same time,” Rechner emphasises. The machines from Pester are used in final packaging that does not contact the product. Almost two-thirds of the delivered machines go into the pharmaceutical and medicine sector, around one-third package consumer products, such as cosmetics or personal-care products. The fully automated machines bundle – such as through tight-band rolling, shrink-tape rolling or full-wrapping – and customise packages for shipment to customers and wholesalers. They can be packed and palletised both in foil and in cartons. Many of the customers of the long-established Allgäu company are global players in the pharmaceutical sector but also large contract packagers. Whoever thinks this is nothing special is wrong.
The crucial point is the hundred-percent control and tracking that the European Directive requires for packaging and shipping of these products. Through a sophisticated, digitalised track-and-trace system, all products are one-hundred-percent recorded and registered, and the data are stored by exact batch for tracking. This also makes imitating more difficult and protects the products from counterfeiting. This is aided not only through several high-speed cameras and sensors; even the suction plate is parameterised. In addition, collision recognition ensures, for example, that no damage occurs or cartons are lost if the plate is installed incorrectly. That, of course, would be disastrous.
Securely package and trace expensive medications
The packaged goods can quickly reach very high values. If, for example, an ultra-modern, new medication for treating cancer is packaged, the value of each pallet can be worth well into the hundreds of thousands. The process times for packaging, customising and implementing are not the greatest challenge. Still, for Pester, part of the company philosophy of “easy to buy from” means always making the machines better in operation. And in setup times, that is, when changing the suction grippers, the developers recognised great potential. “In addition, sometimes our customers stipulate the maximum time the changeover to another product can take,” says the development engineer.
“In the past, operators had to unscrew four star screws and simultaneously hold the heavy plate, which was difficult. That’s almost impossible with just two hands,” Rechner remembers. This is much more convenient with the new technology. “Through the latching function of the zero-point clamping modules, changing the suction plates is not only easier and faster, it’s also completely intuitive. If you do it once, you never forget how,” Guggenmoos adds. Moreover, the plate is no longer as heavy, since it is made additively from plastic. “That has the side effect that the robot can now lift more product weight,” explains Rechner. “And so switching to these clamping modules has really been good for us.”
Two small power packages do the job safely and precisely
Two RM251 mechanical zero-point clamping modules from AMF with latching function are screwed into each suction plate; the matching clamping sleeves as counterpart are located in the holder of the robot arm. “In our assortment, we have both the clamping sleeves for screwing in and for pressing in,” Guggenmoos informs us. The light power packages, which weigh just 28 g, retract with a force of 100 N, and then lock and hold the plate firmly with 1000 N each. “That is enough to hold the suction plate securely on the robot and resist the acceleration forces, and is enough to lift packages weighing 20-25 kg,” Guggenmoos says. “But we don’t use close to that capacity,” Rechner adds. The housing and pistons of the modules are hardened for a durable life. They can be opened mechanically and close securely through an integrated spring, which – also mechanically – applies the necessary force. That takes place with process reliability and repetition accuracy of less than 0.1 millimetre. The entire array is easy to clean. It is usually enough to occasionally blow out the surfaces with a pneumatic pistol when changing the format part, and then you can continue.
Looking beyond boundaries brings new solutions
“If these zero-point clamping modules with latching function didn’t exist, we’d need to invent them,” says Rechner in conclusion. And Guggenmoos adds: “We’ve had the products in our assortment for a long time. They’re the smallest zero-point clamping modules from our product portfolio. What’s new here is the application area.” And so the project shows again what solutions can result when the participants look beyond boundaries.
