Medical technology compatible ball bearing material from Igus

Igus is expanding its range of high-performance plastics for medical technology. New in the medical range is xirodur MT180, a material for lightweight, lubrication-free, and hygienic xiros deep groove ball bearings – certified to the strictest standards including USP Class VI and DIN EN ISO 10993.

Because the material has certified biocompatibility, manufacturers of medical technology such as bioreactors can select certified bearings and save time and money when approving their products.

In medical and pharmaceutical technology, machinery and plant manufacturers are increasingly replacing metal components such as deep groove ball bearings with mating parts made of high-performance plastic. The advantage of using Igus’ xiros series ball bearings is that they run without lubrication, are maintenance-free yet also low-friction and hygienic.

But not every plastic is suitable in every medical technology application. Until now, manufacturers have often had to plan time and costs for the certification of new assemblies. “That is why we invest a lot of energy in research and development to bring materials to market that are already certified to the medical strictest standards,” says Rob Dumayne, drytech director at Igus UK.

“Materials that manufacturers of medical technology can use without hesitation. One of our latest developments is xirodur MT180, a biocompatible material from which lightweight, hygienic and non-magnetic xiros deep groove ball bearings can be manufactured.”

The new xirodur MT180 ball bearings are suitable, for example, for bioreactors that cultivate microorganisms in a culture medium. Reactors like these played a crucial role in producing RNA vaccines during the Covid-19 pandemic. The xiros ball bearings can be used in the agitator.

The bearings do not pose a risk of contamination, and this is certified by a classification according to USP 88 Class VI of the United States Pharmacopeia (USP), a US pharmacopoeia or pharmacy directory that sets quality standards for drugs – one of the strictest standards worldwide.

“Our new material xirodur MT180 has thus achieved the highest biocompatibility class,” explains Dumayne. In this class, the high-performance plastic is even approved for contact with the bloodstream and is therefore as biocompatible as materials used in implants. The material also complies with DIN EN ISO 10993 for medical devices.

The single row xiros deep groove ball bearings made of xirodur MT180 belong to the family of rolling bearings. These consist of four components: an inner and outer race, a cage, and balls. The cage and bearing races are injection moulded from xirodur MT180, and the balls are made of stainless steel or glass. Glass ball bearings are completely non-magnetic and electrically insulating, so they are also suitable for magnetic resonance imaging (MRI), an imaging method that uses a pulsating magnetic field to visualise the inside of the body layer by layer.

Since the magnetic field is many thousands of times stronger than the Earth’s magnetic field, classic metal rolling bearings are unusable for MRI. “Ball bearings made of xirodur MT180 are not only suitable for bioreactors and MRI, but also for prostheses and orthoses, X-ray robots, laboratory equipment and hospital beds,” emphasises Ulf Hottung, industry manager for medical technology at Igus in Germany.

Dumayne adds: “The ball bearings made of high-performance plastic are not only corrosion and dirt resistant, but also up to 50% lighter and particularly durable. To ensure quality and safety, we put each of our ball bearings through its paces in our in-house test laboratory.”