Fast accurate water vapour permeability metering

Edited by the Processingtalk editorial team Aug 3, 2005

Versaperm is launching an entirely new instrument for the fast and accurate measurement of water vapour permeability, crucial in understanding a paper's handling, printing and pulpability

Versaperm Limited, a world leader in water vapour permeability, is launching an entirely new instrument for the fast and accurate measurement of water vapour permeability - which is both the world's most damaging contaminant, and is also crucial in understanding a paper's handling, printing and pulpability.

Water vapour is omnipresent and highly invasive.

It can cause ink to go-off too quickly (or slowly) can cause machines to jam and is the easily the most important characteristic of any coating.

Using materials with inappropriate vapour permeabilities costs the UK alone considerably over GBP100M every year and needlessly reduces the active life and effectiveness of a huge range of preparations.

The Versaperm WVTR (Water Vapour Transmission) MK VI meters: highly automated computerised control can cope with several samples at a time - and still give a reading in as little as 30 minutes for some materials.

The conventionally gravimetric measurement technique takes several days and gives significantly less accurate/reproducible results.

Additionally the instrument can be configured to measure the diffusion rates of most gaseous elements (O2, CO2, N etc).

The MK VI needs very little re-calibration and requires, at most, minimal training to give results that can be accurate to better than one part per million (with some samples a few parts per hundred million).

Sensitivities are typically in the range 0.05 - 3200g/m2/day.

A wide variety of options is available, depending on the specific applications, but both single and multi-sample systems, plus a range of measurement chambers and sensors can be supplied for testing samples from the size of a thimble up to a pallet load and beyond.

As well as vapour transmission, the equipment can be used to measure the Equilibrium Relative Humidity (ERH) of substances - that might otherwise be decomposed by normal water content measuring techniques.

The company also operates a laboratory service to measure permeability for companies where the volume or logistics of measurements does not demand a dedicated instrument.