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TU-Clausthal Institute of Organic Chemistry

Glass

Borosilicate glasses are highly resistant to chemicals and temperatures and are mainly used in laboratories, chemical process engineering and in the household. The temperature resistance and insensitivity to sudden temperature fluctuations of borosilicate glass is due to the low coefficient of thermal expansion of borosilicate.

The glasses consist of 4 to 8 % alkali metal oxides (sodium oxide Na2O, potassium oxide K2O), 2 to 7 % aluminum oxide (Al2O3), up to 5 % alkaline earth metal oxides, 70 to 80 % silicon dioxide (SiO2) and 7 to 13 % boron oxide (B2O3).

Special designs

The following special designs can be made from borosilicate glass in our workshop:

  • Modified standard parts and apparatus
  • New developments, e.g. flat-head glass discharge tubes for better rotation of the ground joint
  • Special coolers with specific outlets
  • High performance double jacket intensive cooler
  • Special electrodes: copper, platinum and alloyed steel
  • High vacuum taps with ventilation
  • Borazine synthesis apparatus
  • Temperature-controlled dropping funnels
  • Chlor-alkali electrolysis apparatus
  • Double-walled electrochemical cells from DN 60
  • GC glass columns
  • Metal magnetic floats for level measurement
  • Frit melting up to Ø 100 mm
  • Special circulating stills
  • Special bomb tubes
  • Glass-glass connection with intermediate glasses
  • Glass-metal melting
  • Falling film apparatus
  • Horsetails
  • Vacuum systems - pumping stations
  • Chemical process systems
  • Repairs of viscometers
  • NMR rinsing machines
  • Thermocouples glass/metal e.g. platinum/rhodium
  • water monitors
  • Repair of platinum electrodes
  • Temperature sensors made of special glass with platinum thermocouples
  • Lead glass repairs in glass apparatus construction
  • Glass melting of special metals e.g. Vacon 10® (KOVAR®, Pernifer 2918®)
  • Processing of special melting glasses e.g. 7510, 8245, 8250, 8230, 8243, 2877 (G20), 8448, 8449
  • Mini-Plant
  • Platinum welding
  • Special short-path drip catcher
  • Salt bridges
  • Mercury or oil diffusion pumps
  • Various glass coatings