Efficiency through automation

Pfizer, Inc. is currently the biggest pharmaceutical producer in the world, with an annual turnover of approximately 45 billion US-Dollars and 122,000 employees worldwide. The company is market leader in prescribed drugs, consumer healthcare and animal drugs. In Germany the consumer healthcare sector consitutes more than 90 % of the total revenue. With its headquarters based in Karlsruhe, Pfizer has several centres in Germany where various employees work in research, development and manufacturing to maintain and increase the high quality and effectiveness of their pharmaceutical products. To meet these requirements, Pfizer utilises the latest automation and information technology within their plants. There is constant testing and implementation of new technologies to achieve a higher degree of performance whilst concurrently achieving a rapid return on investment.

The end of the production line is an especially important area with regards to security requirements in the pharmaceutical industry. At the end of production sensitive pharmaceutical products have to be filled in their respective containers and sealed correctly. Pfizer needed to automate the sealing and laser etching of tubes for a liquid sampling bank. They had looked at various robotic pick and place systems, but these were found to be expensive and over-complex for this type of application. Pfizer decided to build their own machine. The main aim was to design and build an in-house machine that could cut out silicone bungs and place them in sample tubes. The machine had to cut out the silicone bungs from a matrix of 96 and then insert the bungs into 96 tubes arranged in an 8 x 12 matrix. A rotational action was needed for both actions. Accuracy plays a major role during this process. Both these processes had to be accurate to 60.1 mm since the shoulder on each bung was less than 0.5 mm and the tubes needed to be pro-perly sealed. Repetition was another target. Pfizer were also looking for 100 % success rate for sealing each of the 96 tubes. Even the slightest imprecision would not be accepted. Not only were the chemicals expensive but if one tube was not sealed properly, the whole tray of 96 would be rejected. Productivity was a further aim. Over 1 million tubes in 3 months needed to be sealed to meet production targets.

Pfizer selected the linear drive system LinMot from Quin Systems. LinMot servo controllers are normally used as drive controllers. Using signals from a supervisory control system, the motors drive the motion to the positions required. This action can be combined with the use of integrated motion profile curve functions. This was found to be especially useful for tailoring the motion when inserting the bung into the tube. This allows changes in set points to be carried out in an optimised, smooth and gentle manner. Customised functions, complete sequential control and PLC functions can be integrated with the servo controller using application software.

Quin sized and supplied the linear servo system, comprising motors and multi-axis control units. A PLC co-ordinates the pre-stored moves in the LinMot control units. A great advantage was that the motion programming was simple and capable of being undertaken in-house. The stored profiled motions saved time and helped with accurate tube sealing. Finally, a simple support structure was also engi-neered in-house, using standard parts (linear bearings, etc). The success of the new system is directly measurable: With the help of the drives from Quin Systems Pfizer was able to significantly increase the throughput of the machine. Now it cuts and bungs 96 tubes in 13 min, is used 24 h/d seven days a week and achieves a record of 100 % reliability.

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Further information on LinMot

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