TPi September 2015

products & developments

The permeability problem Most valves, mastics, seals and gaskets are a good barrier against liquids. However, some of them leak when it comes to vapours, such as hydrocarbon products and water vapour, which can actually permeate through the materials that make up the walls, seals and mastics. According to Versaperm Ltd, many materials, such as cellulose, EVOH or PVOH, allow water vapour to flow through almost as if they were not there. Some plastics allow hundreds of times more vapours to flow through than others. This leads to gaskets and seals not actually sealing properly for some vapours.

precise task at hand. Measurement techniques include flame ionisation, catalytic combustion, infrared, photoionisation, mass spectrometry, capacitive,coulometric,electrochemical, electrolytic, gas chromatography, impedance, infrared, paramagnetic, pressure measurements, semiconductor and thermal conductivity. Versaperm’s permeability meters typically achieve accuracies in the parts- per-million range (parts-per-billion with some gases). The systems are suitable for use on most materials, membranes, containers, films, laminates, coatings and components. They are also suitable for general testing, and QC, lab and development work. As well as manufacturing the instruments, Versaperm offers a permeability laboratory service for companies that need to test samples on an irregular basis.

Versaperm offers a solution to this problem with its range of dedicated and generic permeability measurement instruments. The equipment is both accurate and simple to use. For some applications it can produce results in as little as half an hour, as opposed to the days or weeks taken by the conventional technique of gravimetric testing.

Versaperm Ltd – UK info@versaperm.com www.versaperm.com

A wide range of application-dependent sensors is available depending on the

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Tube Products International September 2015

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