When you enter the Aesculap AG factory premises, you feel a bit like you've traveled back in time. In one part of the factory premises, historic buildings with brick facades house state-of-the-art offices and production facilities. The family-owned company was founded in Tuttlingen over 150 years ago and has remained loyal to the location ever since. Since 1976, Aesculap has been part of B. Braun, one of the world's leading manufacturers of medical technology and pharmaceutical products and services. With around 3,400 employees*, Aesculap is the largest employer in the city and is aware of its responsibility - this also applies to the architecture of the site. The company carefully preserves the old building structure. This means that new occupancy concepts have to be developed time and again.

This is now also evident in the premises of the former company cafeteria. Eating is now absolutely forbidden there. This is because the former cafeteria is now a state-of-the-art clean room for the final production of sterile surgical instruments and medical technology components. To this end, Aesculap AG invested in the largest and most modern cleanroom facility on the site to date. A controllable environment was created on almost 1200 m², which protects the sensitive products from contamination during production. The cleanroom system achieves ISO Class 7 and 8 and is operated with 88 filter fan units that use ULPA 15 high-performance filters to ensure the entry and circulation of the purest air.

Clean production in three shifts
In the clean room, employees work in up to three shifts. The employees' protective clothing must not be removed at any time and must fit properly, jerky and rapid movements must be avoided, and conversations must also be kept to a minimum. All this serves to reduce particle emissions by the personnel.

Ralf Ketterer, segment manager at Aesculap, is responsible for the smooth running of cleanroom production and knows that in addition to the technology, it is the employees* who are most important for safe production: "Often, little attention is paid to the working atmosphere when planning a cleanroom. We deliberately wanted to change this and have been confirmed by the feedback from our employees. Everyone feels very comfortable. The room is bright, the space has been used optimally and, above all, it runs extremely quietly." However, the new facility is not only generously designed, but above all geared towards growth. A possible expansion has already been planned and provided with the necessary connections.

Modular system with expansion options
Before work could even begin on site, a long period of planning and conversion lay ahead of everyone involved. To begin with, the rooms were completely gutted and extended. The cleanroom company Schilling Engineering was commissioned with the detailed planning, delivery and construction of the cleanroom. Thanks to the modularity of their CleanMediCell. system, developed in-house, the requirements for future expansions can be met without any far-reaching reconstruction measures. Media columns supply the large cleanroom with connections via the ceilings. In the event of an expansion, the connections can be prepared in the accessible ceilings so that the cleanroom only has to be opened briefly, resulting in only minor interruptions to production.

For flexible expansion, the cleanroom walls are double-boarded so that an extended media supply can also be easily installed via the walls. "We have planned the cleanroom for the next 10-15 years. About a third of the space is not even needed yet," Ketterer explains. The cleanroom's modular system gives us flexibility here, "which was very important to us."In a cleanroom of this size, the entry and exit of personnel and materials is also crucial. The personnel airlocks, which are separated by gender, take up 165 m² of space. Various material locks, the size of which has even been designed for the case of transporting new machines and complete plants, simultaneously ensure that the material is brought in safely. The finished parts are then discharged via a conveyor belt with automatic lift doors leading to a vertical conveyor shaft. One floor below, final packaging takes place - then already outside the cleanroom.

The material locks and entrance doors of the bright cleanroom have a special feature. Even from a distance, the green LED lighting can be seen, signaling that the system is in trouble-free operation and a door can be opened. If the airlock has to be flushed first after entry, the room lights up blue; if a door is open, the intelligent lighting turns to red. Ketterer is convinced of this function: "It actually makes it easier to enter and get materials in, because the employees* can see from a distance whether the airlock is free." "I can even see the green light from other buildings, so I know everything is okay. It has a calming effect on me in the meantime."

Structure with spacing rules
The cleanroom facility at Aesculap is the largest project to date for the cleanroom specialist from Wutöschingen. Initially entrusted with the engineering, the service technicians of the family-owned company in southern Baden were able to be assigned exactly according to plan after the contract was awarded and were able to carry out the construction without any delays. The large profile sections had to be brought into the third floor via the windows using a cargo crane. After several months of intensive installation work, the cleanroom was handed over ready for operation with the final qualification. Ralf Ketterer is fully satisfied with the entire process: "One should also not forget that the installation, with the start of construction in March 2020, fell exactly at the beginning of the Corona period. However, the service technicians from Schilling flexibly adjusted to the new situations at all times and really got stuck in so that the construction could be completed on time," concludes Ketterer.

This article was published: contamination control report 2/2021