The Netherlands-based Eriks group, which comprises 50 companies and is present in eight countries, is introducing a range of sealing rings for the dairy industry produced from a special rubber compound developed in conjunction with Belgian-based division of Milliken Chemical.
The compound, termed Elastoguard-HNBR, is a high temperature formulation that incorporates Milliken's Elastoguard silver-based biocide, which permeates parts moulded from the material to provide long-lasting protection against bacteria.
The anti-microbial performance provided by the Elastoguard additive is said to be maintained even after parts are subjected to repeated washing and surface abrasion. The companies say that other potential applications for the compound, which is resistant to temperatures up to 150C, include seals, gaskets, profiles, castors, diaphragms and levelling feet.
The Eriks sealing rings, coloured yellow to facilitate recognition, are being injection moulded, in 10 sizes - with outside diameters from 20mm up to 114mm - according to the DIN 11851 standard. In addition to their anti-microbial performance and steam resistance to 150C, the rings are also said to have superior resistance to oils, grease and ageing compared with standard grades of NBR.
They also provide optimum sealing characteristics. First applications for the coupling rings will be in the dairy market, but evaluation programmes are also underway with the brewing industry and food processors. Other, longer-term targets include the medical market and suppliers of laboratory equipment.
"The dairy industry is proving to be very positive in its acceptance of the sealing rings produced from Elastoguard-HNBR," said Eriks international product manager sales and rubber, Marc van Oost. "They are a cleaner product, free of microbes that require less on-line cleaning and will lead to reduced machine downtime. We expect, also, for applications to develop rapidly in other markets where there is a requirement to eliminate bacteria and microbes as completely as possible."
Milliken and Eriks have a technical and commercial co-operation agreement to develop applications and markets for the Elastoguard-HNBR compound. The agreement includes visiting customers, running trials and setting up production facilities, and is already underway in Belgium, Holland, France and Germany. Subsequent developments will focus on Scandinavia and the UK. The anti-microbial technology is also applicable to other types of rubber than NBR, including EPDM, silicones and thermoplastic elastomers.
Milliken's Elastoguard anti-microbial additive is a silver-sodium-zirconium phosphate ion-exchange resin that is non-leaching. Once the moulded part has been vulcanised, the additive is encapsulated in the rubber matrix where it permeates the entire part to give skin-to-core protection. Bacteria absorb the silver ions released by the additive, which break down their cell walls and destroy them. The silver ions are also released into areas that are hard, or almost impossible, to clean with classical detergents, such as hairline cracks in seals.
The silver-based Elastoguard ion-exchange resin in Elastoguard is tasteless and odourless. It has been registered by the FDA (Food and Drug Administration), the EPA (Environmental Protection Agency) and the EFSA (European Food Safety Agency).