Hallo Pier,
I can give you some more information because we have a collection of
various glass types used for lab purposes. Several types of glasses are
similarly (i.e., Rasotherm, Duran). Here a short overview:

Vycor:
SiO2    B2O3    Al2O3   CrO2    Na2O    As2O3
96%     ca 3%   both <1%        both traces
Vycor is chemical resistent against alkaline (NaOH) and acidic (HCl) treatment
longt time high temperature: 900°C, shortly 1200°C
see: www.schroeder-glas.com

Reference: Eigenschaften des Glases, Kap. 3
Thuringian Labor Glass
SiO2    Na2O    K2O     CaO     MgO     B2O3    Al2O3
69      10      6       8,5     0,8     2,5     3,8

Rasotherm
SiO2    Na2O    K2O     CaO     MgO     B2O3    Al2O3
79,9    4,1     0,7     0,2     0,1     12,6    2,7
temperature resistent up to ca 450°C

Duran 50 (Schott)
SiO2    Na2O    K2O     CaO     MgO     B2O3    Al2O3
79,7    5,2             0,8     0,9     10,3    3,1
transformation temperature: 568°C

Supremax
SiO2    Na2O    BaO     CaO     MgO     B2O3    Al2O3
56,8    1,3     6,6     4,5     7,8     6,6     22,9
temperature resistent up to ca 700°C; transf. temperature: 715°C

Pyrexglas
SiO2    Na2O    K2O     CaO     MgO     B2O3    Al2O3   As2O3
80,5    3,8     0,4     0,2             12,9    2,2     0,5
transf. tempaerature: 565°C

Typical Borosilicateglass
SiO2    Na2O    B2O3
55-75   5-10    20-35

Hope to help you.
Best regards
Gerhard



Am/Um 14:49 13.12.00 +0200 schrieben Sie:
>Dear all,
>
>This time a question from me.
>In literature a number of different glass types are reported. It concerns
>some names probably originating from the former eastern European producers?
>Names such as: Rasotherm, Uviol-glass, or Supremax (last one used by Fiedler
>and Proksch, 1972) were used. Can anyone explain to me what types of glass
>these are? Borosilicates, silicate glass, .... and what is a comparable
>quality in common glass types.
>
>I hope to get a fast answer - I will move soon from this address and I will
>not be able to look into e-mail as regular as I am used to for the comming
>month.
>
>Best wishes,
>Pier.
>
>****
>Address: see my next message to the list!!!
>****
>
>
*************************************************************
Dr. Gerhard Strauch
Centre for Environmental Research Leipzig-Halle Ltd
Department of Hydrogeology
Theodor-Lieser-Strasse 4
D-06120 Halle
Germany
Tel: ++49/345/5585 206  Fax: ++49/345/5585 559
e-mail: [log in to unmask]
************************************************************