VPS / PR

Collection PR

The colours from the leaded PR series are suitable for decorating borosilicate glass. As with VPS colours, the main field of application of these colours is the decoration of ampoules, syringes and bottles for the pharmaceutical industry, chromatography, and for chemical, laboratory and cosmetics requirements. Special applications for flat glass, such as the toughened safety glass process, must be tested on a case-by-case basis.

Firing range:

620-640 °C slow firing
630-700 °C fast firing

The average coefficient of thermal expansion of the base frit lies within the range of 50-300 °C at 53 x 10-7/°K and 61 x 10-7/°K.

Whatever the application, the colours must always be tested beforehand on the glass that is to be used and under the production firing conditions. The harmonisation of the ceramic colour with the borosilicate glass to be used is heavily dependent upon the weight and thickness of the applied colour. To avoid any micro-fissures or flaking of the colours, they should generally not be applied too thickly.