Kyoto/London - Kyocera has successfully strengthened the development of plain bearings especially for magnetically coupled agitators. Based on universal expertise, Kyocera offers different ceramics for this application from a single source. This guarantees the reliable traceability of the materials. Due to Kyocera’s core competence in technical ceramic, both components are Kyocera proprietary and come from a single source, which guarantees full material traceability. This is especially important in the production of pharmaceuticals and food. The pin and bearing ring are made of different ceramic materials. Both components’ material perfectly match each other with strict tolerances and surface requirements. Thanks to Kyocera’s extensive mechanical machining facility, high quality surfaces with minimal friction in the operating mode and with reduced breakage risk in dry run conditions could be developed.
The key components of magnetic mixers are ceramic sliding bearings which are in direct contact with the mixed product. Frictional wear, temperature changes and corrosive attack by cleaning chemicals determine the material selection for these highly stressed components. Usually, the male bearing is made from zirconium oxide and the female bearing is made from silicon carbide. The fixed bearing journal made of zirconium oxide is firmly connected to the tank plate of the tank. The static, robust male bearing is attached to the vessel's tank plate and the rotating female bearing is integrated and sealed with the mixing head. The inner bearing made from zirconium oxide has increased resistance to impacts and damage from sudden rotor settling or during assembly/disassembly of the mixer. The outer bearing made from silicon carbide provides superior abrasion resistance and low surface roughness.
In the production of pharmaceuticals and in the food industry, several substances such as powders and liquids are mixed for being employed in aseptic equipment. Hence, complete sterility of all mechanical components in such equipment is required. In this type of application magnetic stirrers are commonly used where there is no mechanical connection between the motor and the rotor of the stirrer, and the torque is transmitted by means of a magnetic field. Magnetic drive mixers without mechanical seals such as slide ring or stuffing box packing minimize the risk of contamination of the final product.
The hardness of Kyocera’s sliding bearings ensures long lifetime and no particle shedding. Thanks to the sterility and inertia of the ceramics, the tank stays maximally clean. Ceramic bearings do not require additional lubrication. The resistance to temperature variations of both ceramics allows the use of cleaning and sterilization in place (CIP/SIP).
All of the materials employed for Kyocera’s bearings comply with applicable FDA requirements and USP Class VI classifications.