Kopp Glass of the USA has announced the successful installation of two annealing lehrs manufactured by specialist EW Bowman.
The installation, according to Kopp Glass, is part of a major capital improvement programme that begun more than a year ago. The lehrs will enable the technical glassmaker to provide more consistent annealing, thus enabling better lens performance in its target applications. They also enhance the capability anneal intricate and difficult shapes, which would not have previously been achievable.
In addition to providing a better environment for annealing, the lehrs will also be used for colouring and decorating processes. They are designed to provide better colour consistency with red and yellow coloured lenses.
It will also be possible to cure decorating enamel used to opaque certain portions of the lens surfaces using the lehrs.
“The convective heating methodology utilised by the new lehr equipment provides improved temperature uniformity over an increased furnace volume, thus producing more consistent colours and an improved anneal on our thick, intricate glass designs,” said William Chen, Director of Research and Engineering at Kopp Glass.
Both lehrs were manufactured in the USA and were designed to be as energy efficient as possible. Natural gas is used to fire the lehrs, while electricity is used to power the eight circulating fans within them. The design allows temperature control within a 10°F range.
