China trials anti-bacterial stainless steel

CHINA: In a development with potential for commercial refrigeration equipment, a Chinese research institute has produced trial production sheets of an anti-bacterial stainless steel.

The material, which could potentially prove to be very attractive to a wide range of industries and users, is referred to as Cu-bearing anti-bacterial stainless steel. It has been produced following research carried out by the Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS) in Shenyang in north east China.

The Cu-bearing anti-bacterial stainless steel is said to combine the strength and corrosion resistance of stainless steel with the strong anti-bacterial characteristics of copper.

Around 40 tons of type 304 Cu-bearing antibacterial stainless steel have been produced by the Institute in a width of 1200mm and different thicknesses of 0.4-2.5mm.

The material is said to have exhibited excellent antibacterial performance under the inspection of Institute of Physical and Chemical Technology, CAS. In addition, it is said to have met the state regulation on bio-safety for metal ions release and cytotoxicity under the inspection of Institute for Food & Drug Inspection of China.

According to the research team, several manufacturers are already co-operating with IMR to develop different antibacterial stainless products, including sinks, air conditioning trays, tablewares, washing machine drums, surgery devices and orthopedic implants.

Copper is well known for its ability to kill bacteria but has previously only been used as a coating. In tests, the Cu-bearing stainless steel is reported to have shown strong anti-bacterial rates against both Escherichia coli and Staphylococcus aureus. It also inhibited the formation of bacteria on the surface of the stainless steel due to the release of Cu ions.

While the producers do not provide details of exact composition of the new material, previously published research has indicated the use of 4.5% copper.