The direct relationship between a material being closer to its elastic limit (when using maximum weight in combination with full speed) and a large number of load changes means changes in a material’s microstructure may result in microscopic cracks. Over the course of operation, these “microcracks” will grow. In a worst-case scenario, the entire rotor may crack during a run, resulting in a centrifuge crash. Rotors and lids made of plastic may have a higher risk of experiencing microcracks. Metal rotors and lids, for example those made of aluminum, are more stable.
Plastic rotors, on the other hand, are highly resistant to chemicals, but can only withstand a limited number of autoclaving cycles before the rotor’s aerosol-tightness is significantly reduced. After a certain number of cycles, plastic rotors cannot be used anymore, and they have to be replaced.
Rotors and lids made of metals like aluminum are more applicable in this case.
With these rotors and lids, you only have to replace the sealing ring after a certain number of autoclaving cycles.