Finnish company Glaston has partnered with arcon to launch measurement equipment and technology to reduce the iridescence of toughened glass.
The Isotropy value scale has been developed by German group arcon to measure the iridescence pattern in toughened glass.
According to this scale, with the new technology the value of tempered glass is 95% or more, which is way beyond the normal levels of 55-60% achieved by standard furnaces on the market today.
In practice, the value of 95% or more means that iridescent patterns cannot be seen without the use of polarised sunglasses.
The measurement equipment and the related technology will now be available as an option with new Glaston flat toughening furnaces or can be provided as an upgrade for existing Glaston toughening lines.
Iridescence is a phenomenon inherent to toughened glass and not a fault as such. Iridescence is a result of stress variations in the glass, which in turn is caused by local glass temperature gradients during heating or quenching in the toughening process.
The resulting iridescent pattern depends on the machinery used, and the intensity of the iridescent pattern varies according to the amount of polarised light at the point of observation.