An Interview with Guenter Liebhart, Design Engineer

Expertise Series

Bosch Engineer Interview, KKE Series – capsule checkweigher

Germany is renowned globally for well engineered and quality products. What influenced you to become an engineer?
I was first a toolmaker apprentice as a young man and this influenced me to learn more about mechanical design.

Why did you choose to work for BOSCH?
My final project for my mechanical engineering degree was done here at Bosch Packaging. This was my first contact with the company and its packaging technology. While being employed by another company, for design work, I was contracted to assist Bosch on a project. Some time after that project was over I joined Bosch.


Guenter Liebhart


What machines have you worked with in your current position?
I’m currently working with the capsule checkweighers, KKE 1700, 2500, 3800 and the GKF 2500 capsule filler. Previously I worked on the GKF 2000. One specialty I have is the design of the tablet-specific dosing disks used on the GKF for feeding tablets into capsules.


What were some design considerations with the current Bosch KKE capsule checkweigher?
We wanted to define the separation of mechanical and process areas. This was achieved with a cantilever design for the process area. The mechanical cabinet is also separate from the control cabinet. Batch records and modern 21 CFR Part 11 compliance was required by the market, which lead to an IPC-based control system. This platform also allows for software version upgrades.


What engineering projects are currently being undertaking on the KKE capsule checkweighers?
I did the design work on the current KKE 2500 to be used in a containment environment. This unit is for use in-line with our containment encapsulators. Changes from the original design included modification of the doors so they could be sealed and maintain a slight under pressure. Another significant change was made to the frame to increase the accuracy to < 2mg.


With the old generation of KKE 1500/2000 machines an anti-static bar was a common option. Why don’t we see them on the KKE 1700/2500/3800 machines?
Because the orientation of the weighing pan on the older KKE 1500/2000 allowed for static to interfere with the weight measurement. The static bar above this area, as an option, was the best solution. When the design work started for the new KKE line we wanted to find a solution with no need for anti-static bars. The new unit was designed in such a way that the overall configuration of the weighing mechanism did not allow for static to be an influence in the weight.

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