Schott Glas

Andreas Berndt

Marten Walther

Dirk Schlatterbeck

Roland Buerkle

Reiner Mauch

Andreas Weber

Inka Henze

Heinrich Ostendarp

Rolf Suennemann

A method of protecting a glass substrate, especially a display glass or a hard disk blank made from a glass or a glass-ceramic, from unacceptable surface damage and scratches, often leading to glass breakage, during processing and transport, is described. This protective method includes applying a removable protective coating made of at least one polymer layer, or at least one polyvinyl alcohol layer, to the glass substrates by spraying or rolling the polyvinyl alcohol or a polymer solution of the polymer to be applied in a polar organic solvent, onto the glass substrate, or dipping the substrate into it. Then when the substrate is ready for its end use, the protective coating is removed by washing in water or polar organic solution so that a residue does not remain on it. The glass substrates, protected in this manner have outstanding surface quality and improved hard disk blanks can be economically produced from them.

Method of protecting glass substrate surfaces

A method and apparatus is described, with which individual rectangular glass panes of thickness between 0.03 mm and 2 mm can be cut from a glass band ( ) drawn vertically from a hot forming device ( ) in an in-line process with reduced rejects and reduced waste. The method provides that the glass band ( ) drawn vertically downward through a vertical zone is cooled below a lower cooling point of the glass and subsequently is deflected through a bending zone ( ) with a bending radius between 0.1 m and 4 m into a horizontal zone ( ) in which it is horizontally oriented. The vertical alignment of the glass band ( ) in the vertical zone ( ) is continuously monitored. At least one cutting process is performed on the horizontally oriented glass band ( ) in the horizontal zone ( ). The device ( ) for monitoring the vertical alignment of the glass band ( ) includes at least three sensors ( &prime;) that detect the glass edges These sensors can be mechanical rollers.

Method and apparatus for making individual glass panes

A method of protecting a surface of a display glass or a hard disk substrate during processing arid transport includes applying at least one polyvinyl alcohol or other polymer protective layer on the surface, which is soluble in polarorganic solvents, so that the layer can be removed after processing and transport by washing in heated water or a polar organic solvent without leaving residues on the surface. The polyvinyl alcohol used to make the protective coating has an average molecular weight of &gE; about 60,000 g/mol and a hydrolysis degree of &gE;95% and the at least one polyvinyl alcohol layer is dried by heating at temperatures of about 150&deg; C. or less to form the protective coating after applying the polyvinyl alcohol layer. The other polymers are less soluble in water than polyvinyl alcohol but are easily removed with organic solvent.

Method of protecting surfaces of glass substrates

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Oldenburg, Germany

Andreas Berndt