Flex­ible assembly of devices

Flex­ible like never before: A new trans­porta­tion system opens up a wide range of options for Harro Höfliger in the design of future pro­duc­tion lines. As MOT Flex, the tried-and-tested MOT plat­form demon­strates its strengths in the agile assembly of med­ical and phar­ma­ceu­tical prod­ucts, for instance auto-injectors.

Quietly buzzing servo-con­trolled shut­tles speed around a cen­tral oval on guide rails – the so-called tracks. They accel­erate, decel­erate, group and arrange them­selves with the com­po­nents or prod­ucts they have picked up before reaching the down­stream pro­cessing sta­tion. At the end of this fas­ci­nating chore­og­raphy there is a per­fectly assem­bled auto-injector which allows patients to admin­ister their drugs with a pre­cise dose.

With its new intel­li­gent trans­porta­tion system, the tried-and-tested MOT assembly plat­form offers sig­nif­i­cantly more flexi­bility in pro­duc­tion. Indi­vid­u­ally con­trol­lable shut­tles based on linear drives move indi­vidual parts and the end product quickly and flex­ibly from one sta­tion to the next. Mag­netic force keeps the highly dynamic trans­port vehi­cles securely on track. The system soft­ware always ensures suf­fi­cient safety clear­ance between the shut­tles and pre­vents them from col­liding. Spe­cial track switches enable agile split­ting and merging of product streams. This flex­i­bility also gave the new Harro Höfliger assembly plat­form its name: MOT Flex.

Mag­netic force holds the indi­vidual shut­tles on the guide rails.

“The drive system offers us a mul­ti­tude of new options and has what it takes to fun­da­men­tally change the design and oper­a­tion of pro­duc­tion lines,” says Rainer Wol­bers, Oper­a­tions Director Assembly Tech­nolo­gies. “The MOT Flex is char­ac­ter­ized by a small foot­print and an eco­nom­ical work­flow. The infeed and out­feed of prod­ucts can also be recon­cep­tu­al­ized, because it is pos­sible to con­nect tray­loaders and pal­letizers directly to the intel­li­gent trans­porta­tion system without pucks.”

varying speed

Format changeovers can be car­ried out much more easily and quickly than with con­ven­tional chain drives. This allows for assembly of diverse med­ical and phar­ma­ceu­tical devices, such as pen injec­tors, auto-­in­jec­tors, inhalers and many more, on one line. “Depending on require­ments, par­allel pro­cessing sta­tions, buffer zones and much more can be real­ized for our cus­tomers,” Rainer Wol­bers explains. “The capa­bility of varying speed and accel­er­a­tion between pro­cessing sta­tions allows the shut­tles to be dis­trib­uted to mul­tiple sta­tions in time-crit­ical processes. The effort required for less demanding tasks like pres­ence mon­i­toring, how­ever, can be kept to a minimum.”

“The trans­porta­tion system sets com­pletely new stan­dards in terms of flex­i­bility.“Rainer Wol­bers,
Oper­a­tions Director Assembly Tech­nolo­gies at Harro Höfliger

The new MOT Flex with the inno­v­a­tive shuttle system was first used in a line for the final assembly of auto-­in­jec­tors. The core task in this project was to insert the drug-pre­filled syringes into the syringe housing with high pre­ci­sion and to press them in reli­ably according to the manufacturer’s instruc­tions. Printing the auto-injector with laser tech­nology was also part of the process. Spe­cial atten­tion was paid to effi­cient han­dling and gentle, smooth trans­port of the syringe without any glass-to-glass contact.

On this line, two robotic arms accu­rately grip the pre-assem­bled syringe units from the tray, which is fed via Harro Höfliger’s TS Pallet Euro pal­letizer, and places them in the shut­tles. These speed along with their trans­ported load to the first pro­cessing sta­tion. Here the syringe unit is sep­a­rated again and the drive unit for trig­gering the injec­tion is removed in order to insert the pre­filled syringe. Then the device is reassem­bled in the steps to follow. After the sub­se­quent quality con­trol, the nimble trans­port vehi­cles deliver the fully assem­bled auto-injec­tors back to the robot sta­tion: The gripper arms care­fully pick up the end prod­ucts and load them in the fin­ished trays, which are auto­mat­i­cally placed on pallets.

The new drive tech­nology enables a very com­pact design. ­Tray­loaders and pal­letizers can be linked directly without pucks.

Mul­tiple options

The shut­tles have already started the next round and are whizzing around the oval with a new load. “The trans­porta­tion system sets com­pletely new stan­dards in terms of flex­i­bility,” says Rainer Wol­bers. “This makes it easier than ever to assemble com­pletely dif­ferent prod­ucts on one line.”

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Photos: Helmar Lünig