Very high chemical resistance

DURAN® borosilicate glass is highly resistant to water, neutral and acid solutions, concentrated acids and acid mixtures, and to chlorine, bromine, iodine and organic substances. Its chemical resistance is superior to that of most metals and other materials, even during prolonged periods of exposure and at temperatures above 100 °C.
Only hydrofluoric acid, concentrated phosphoric acid and strong alkali cause appreciable surface removal of the glass (glass corrosion) at elevated temperatures (>100 °C).

It is also widely used on an industrial scale in all other application areas in which extreme heat resistance, resistance to thermal shock, mechanical strength and exceptional chemical resistance are required. DURAN® properties are specified in DIN ISO 3585. In contrast to other borosilicate glasses, DURAN® is notable for its highly consistent, technically reproducible quality.

High Temperatur usage

The maximum permissible operating temperature for DURAN® is 500 °C. Above a temperature of 525 °C the glass begins to soften and above a temperature of 860 °C it changes to the liquid state. DURAN® can be cooled down to the maximum possible negative temperature and is therefore suitable for use with liquid nitrogen (approx. – 196 °C). During such use/ freezing. In general DURAN® products are recommended for use down to – 70 °C. During thawing ensure that the temperature difference does not exceed 100 K.

Temperatur resistance at low temperatures

DURAN® can be cooled down to the maximum possible negative temperature and is therefore suitable for use with liquid nitrogen (approx. – 196°C). During such use/ freezing In general DURAN® products are recommended for use down to – 70 °C. When working at low temperatures, the effect of any expansion of a DURAN® vessel’s contents must be borne in mind.

During cooling and thawing ensure that the temperature difference does not exceed 100 K. In practice, therefore, stepwise cooling and heating are recommended. When freezing substances in such items as DURAN® bottles or DURAN® test tubes, the container should only be filled to a maximum of 3/4 of its capacity. Moreover, it should be frozen slanted at an angle of 45 ° (to enlarge the surface area) and dependent on the properties of any screw caps or other components used. For the blue PP screw cap the minimum temperature is – 40 °C.