Class VI is not a performance guarantee

EPDM (ethylene propylene diene) elastomeric seals have received considerable bad press within the pharmaceutical and bioprocessing industries with regard to their operational performance.

Much of the talk has however missed the key point that it is in fact low-cost elastomeric materials, which are unsuited to the demands of the job, that are turning-in sub-standard performance.

The constant drive to reduce unit costs for elastomeric seals is in danger of turning a critical component into a commodity spare part. Many manufacturers, in order to meet the low prices demanded, are buying ‘off the shelf’ compounds, which are selected for their ease of manufacturing rather than operational performance. As a result, whilst pricing points may be achieved, operational capability is often severely compromised.

Seals may well be of a material that is USP Class VI certified, but this is only an indication of biocompatibility and by no means an indication of how the material concerned will function as a seal. Neither does it guarantee the origins and traceability of the elements that go to make up the final compound or provide any certification of the suitability of the production methods that would be involved in making a seal from that compound.

Throughout the development of the Elast-O-Pure® family of products for biopharmaceutical applications, James Walker has benchmarked its progress using comparative testing against compounds already in regular use within the biopharmaceutical industry. In every case, the lower cost elastomers of our competitors have presented problems with regard to their resistance to CIP and SIP regimes, proved difficult to remove from ferrules at change-out, had a shorter life and presented significant issues with respect to intrusion and recession.

The end result of years of research and development for James Walker is now seen in the company’s Elast-O-Pure range of materials. These have been formulated and refined with operational performance as the key driver rather than working to pre-determined cost levels. The result is therefore not surprising – industry leading performance in terms of resistance to chemical and steam cleaning processes, very tight intrusion tolerances, high levels of material purity and exceptional longevity.

Inevitably, performance of this level comes at a higher cost than a commodity seal, but the cost premium is repaid many times over in longer maintenance intervals, increased throughput or yield and reduced failures and deviations.

17 September 2012

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