Braun Melsungen: Accurate and Reliable

TRANSNORM of Harsum has implemented a fully automatic conveyor system for the transport of sensitive infusion set packages for B. Braun Melsungen AG. The 100 m long conveyor lines adapted exactly to the existing building layout and installed below the hall ceiling connect the production area with the automatic packaging lines and palletising robots. Maximum system reliability with the help of technical expertise and quality of the conveyor equipment components such as the controller are ensured as B. Braun operates six days of the week and in three shifts round-the-clock.

The special ingenuity of an intralogistics system is often appreciated only after taking a more careful second glance. This is also the case with the fully automatic conveyor system implemented by TRANSNORM in the factory of B. Braun Melsungen AG at "Pfieffewiesen".

B.Braun - which realises sales of approximately 4 billion EUR and has almost 40,000 employees across four divisions of "Hospital Care", "Aesculap", "Out-patient market" and "B.Braun Avitum"-  is one of the leading companies in the world in the medical industry and supplies its products to more than 50 countries worldwide.

The conveyor system installed at a height of 4 m below the ceiling of the hall is used only for transporting infusion sets packed in PE pouches and, in the process, bypasses the conveyor route from the production area up to the packaging and palletising system.

Dipl.-Ing. (Graduate Engineer) Thomas Höse, who provides Global Technical Support in the "Hospital Care" business division enumerated on the demanding goods being transported: Each unit, which is called a "station pouch", contains five infusion sets packed in pairs that are consolidated with the help of transparent film pouches to one transport unit. Each of the infusion devices consists of the drop chamber with a hose, the roller clamp for adjusting the dose and the so-called "patient connection".

Conveyor system for up to 60,000 infusion set packages per day

In the factory at Melsungen that operates six days a week and round-the-clock, up to 60,000 pouch packages are dispatched under peak load conditions on approximately 120 pallets. As the quantity and weekly operations indicate, absolute system reliability is indispensable. In particular, as Mr. Höse explained, time for repairs, maintenance work and new installations is available only in the course of one week of maintenance in the summer as well as during the New Year period.

Accordingly, both of the new approximately 100 m long conveyor lines were planned in November 2009 and installed, integrated and put into operation in the summer of 2010, explained Dipl.-Ing. (Graduate Engineer) Uwe Ehlers. He is the Sales Manager at TRANSNORM in the Systems Business Division and worked as the Project Manager for the planning and implementation of the two new lines. TRANSNORM has already been operating as the specialist for conveyor equipment for B. Braun for about 20 years and the last installation was a smaller conveyor line at the start of 2009.

Connecting the production and packaging areas below the hall ceiling

The new conveyor system is by no means one that consists of two conventional and by and large straight lines on the floor of the hall. On the contrary, the conveyor routes, which are about 100 m long and installed at a height of about 4 m below the hall ceiling to conserve space, connect the production area in the same building complex but one floor higher with the packaging area.

As far as the process is concerned, the slightly spherical packaging pouches weigh only 300 grams and are filled with five pairs of infusion sets that are transferred via a platform to an S-lift. They are then transferred intermittently through an opening in the ceiling to the conveyor line and finally transported to the packaging station with automatic facilities for packaging in cardboard boxes and palletisation.

The packaging units are fed there via the conveyor belt to the fully automatic cardboard box packing facility. Packaging robots hold the product pouches with a suction gripper and place them in the cardboard boxes provided there, which are placed by another robot on Euro pallets according to a specific packing pattern. The loaded pallets are then transported in a driverless transport system (FTS) operating in permanent shuttle mode directly below the conveyor system into the high-bay warehouse where they are kept on standby for retrieval by the dispatch section. 

Fully automatic process chain implemented to conserve space

This complete complex process chain takes place fully automatically and without any human intervention. The TRANSNORM system is controlled with the help of an S7 controller to which even the S-lift is connected.

The installation of the conveyor system below the hall ceiling, which was more expensive and cumbersome but valuable, meant, on the one hand, constantly free movement for the continuously operating FTS; this takes care of the replenishment of new folding cardboard boxes on the return journey. Meanwhile, on the other hand, it ensures uninterrupted transport of the infusion sets in the direction of the high-performance packing robot. 

"The system is operated with an average hourly capacity of 1,000 units, whereby this throughput is not restricted even with crossings or merging of both lines" emphasised Mr. Ehlers. The focus here was not on speed but the safe and clean transport of sterile products. Infusion sets with damaged outer packing inevitably have to be declared unusable. 

Proven belt conveyor equipment for sensitive goods

"Based on the special requirements for medical products at B. Braun, we have only used belt conveyor equipment here" explained Mr. Ehlers. "And since we implement belt curve conveyors in almost every possible angle, we could adapt the conveyor system optimally to the existing hall layout; we could even implement the demanding linear guides at both transfer stations at the beginning and end of the system both functionally and relatively easily" he continued.

 The complete conveyor system could be implemented by TRANSNORM from the range of modular system building blocks. Mr. Ehlers: "Our conveyor equipment modules - which are proven several times over - are aimed specifically at handling difficult and sensitive products. We are well aware of the so-called non-rigid goods, which also include the "Station pouch" transported here, from the return systems implemented for mail order companies".

However, the stringent FDA standards applicable to the pharmaceutical industry of the American Health authorities also needed to be complied with. As Thomas Höse explained, this meant that even with the requirements prescribed in the system description for TRANSNORM, such as non-toxic systems and special qualities of the surface, there should also not be any abrasion or dust formed and the belts should not emit any particles.

Specific layout and functional requirements of the conveyor system:

 As the Project Manager emphasised, the engineering performance for the system for B Braun "…lies clearly in the specification of the conveyor: It was necessary to specify the appropriate belt deflections, to choose suitable materials, to use energy-saving motors and to match the system precisely with the controller - we could cover all of these requirements optimally with our products".

 As Mr. Ehlers explained, there were even a series of special requirements to be met with respect to the layout of the conveyor equipment lines. "Therefore, for example, a highly reliable interface was to be set up to our conveyor equipment at the ceiling passage of the S-lifts (NERAK) from the production area from above and then we needed to find a route that ran cleanly and accurately along the building contours provided, for example, along the columns".

Redundancies and buffering function by line crossing

Mr. Ehlers also considers it to be a "special requirement" that it should be possible to switch the downstream packaging lines optionally to either of the two conveyor lines as required, which necessitated the construction and installation of a crossing of the lines at a height of about 4 m below the ceiling of the hall.

The possible crossings now provide the required safety and redundancy with the prevalent three-shift operation if, for example, problems should arise with palletisation or at the final packaging system" added Mr. Höse: "The reason being that with the help of the line crossing of the conveyor equipment you can switch smoothly to another packaging machine simply with a mouse click". In doing so, however, criteria such as product uniformity need to be taken into consideration since different infusion sets are produced with 1.8 m or 1.5 m of tube length.

Empty run mode of the system for product change

Moreover, the requirement of the conveyor equipment arising out of this product variance calls for the need to be able to transport different product groups in batches of a single variety to the packaging station. For this purpose, the so-called empty run mode is selected on the system controller that was also implemented by TRANSNORM which releases the conveyor routes for new products as soon as the previous batches of the lines have been handled completely. Overall, there are three operating modes available for the transport and buffering function.  

In addition, the drive motors of the conveyor equipment can be controlled smoothly and continuously with the help of "Movi-Mot" to run at three speed levels and can thus be adjusted flexibly to the throughput requirements of the respective shift.

Expansion options of the conveyor system have already been considered at the time of designing and planning

Therefore, at the time of planning and designing the constellation of the system, it is taken into account that it is cleanly divided into sections right from the very start, as Mr. Ehlers emphasised, and that "…we use the same lengths of conveyors and the same motors, as far as possible, taking the spare parts inventory of the customer into account". In this way, even from the perspective of the restricted timeframe available, any conversions of reconfigurations necessary can be carried out quickly and easily.

Quick reconfiguration and mobile maintenance terminals

The stringent requirements of availability of the system were also taken into consideration for the maintenance work necessary. Consequently, at strategically important points of the conveyor system, you can dock mobile touch-screen panels with the help of which the operating conditions for maintenance and service work can be sensed.

Last but not least, with service-oriented aspects such as these, the conveyor system ensures smooth and streamlined operation - in line with the nature of the lifesaving products that are being transported reliably here round-the-clock.