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2012
Conference Paper
Titel
Novel concept for manufacturing lightweight centrifuge rotors for laboratories
Alternative
Neuartiges Fertigungskonzept für Leichtbaurotoren von Laborzentrifugen
Abstract
Centrifuges have multiple uses in medicine and in laboratories. Most notably, they are used to separate materials, e.g. blood plasma and serums, and produce genetically engineered substances. Centrifuge rotors hold sample containers. Centrifugal forces equaling 25,000 times the force of gravity act on operating rotors and samples at speeds of 20,000 r/min. Unlike present conventional solutions (rotors made of special aluminum alloys), the load-bearing structures of the lightweight rotors presented here are made of carbon fiber-reinforced polymers (CFRP). Given the fibers extremely high load-bearing capacity, lightweight rotors manufactured with this novel technology set new standards for weight, stability and service life compared to current concepts. In addition, the time typically need ed to heat aluminum rotors is reduced by at least 50 %. This complicated design principle necessitates suitable forming tools that reproduce the complex geometries (e.g. undercuts). Therefore, generative (laminate) methods of geometry generation are used for mold making. With their practically unlimited freedom of design, the technologies can, for instance, already produce close-contour cooling channels during mold making. Furthermore, as mentioned, selective laser sintered geometrically complex inserts will reduce the weight of future rotor bodies. Once this novel concept has been implemented, a lighter weight CFRP rotor will be at least 10 % more stable than a lightweight wound rotor. At the same time, its permissible speed is expected to be at least 10 % higher than that of availabl e lightweight rotors in the same class. To this end, comprehensive physical models and new calculation algorithms for the FEM analysis have been developed, which ensure that lightweight rotors can be manufacture reproducibly.