Sanitary seals for food and pharmaceutical applications

They are said to provide longer seal life and tighter sealing, which improves productivity and process optimisation, and to create a safer environment in the day-to-day running of process plants and manufacturing facilities.

Kalrez LS390 seals are available in the UK from authorised distributor Dichtomatik.

There are a number of problems that can be experienced in sanitary seal applications, many of which are related to thermal and chemical resistance challenges, compression set (permanent deformation), and high static friction (stiction). Such issues can lead to intrusion in the production line or dead space, which in turn elevates the risk of contamination or leakage.

Kalrez LS390 has been purpose-designed to overcome these common challenges by providing high hardness properties (Shore A3 88), low stiction, and temperature resistance to 220°C. The seals also offer excellent chemical resistance to process chemicals, WFI (water for injection), and SIP and/or CIP processes. For users, these properties facilitate greater MTBR (mean time between repair), delivering bottom-line cost savings. 

Among early adopters of the parts is a major pharmaceutical plant in Japan. Here, Kalrez LS390 has successfully been deployed in an infusion-drop product operation that uses pure steam SIP. The manufacturer chose Kalrez LS390 because of its improved chemical resistance and low stiction performance. 

Problems had been experienced previously with the company’s existing material (silicone rubber seals), which had issues with steam resistance and high stiction, resulting in a short maintenance period of six months. However, after switching to Kalrez LS390, the performance improvements have been substantial; the sanitary seals provide excellent resistance to chemicals and pure steam SIP, lasting a year without any damage on the contacting surface. These performance attributes have helped to increase productivity, lower maintenance costs and minimise unscheduled downtime, resulting in lower TCO (total cost of ownership).

As a result of their special grey colour, LS390 sanitary seals offer easy identification for correct material selection and application. The perfluoroelastomer can also be used in applications other than sanitary seals.