Schott Ag

Clemens Kunisch

Ralf Jedamzik

Ina Mitra

Lutz Parthier

Kurt Nattermann

Gunther Wehrhan

Axel Engel

Armin Vogl

Thoralf Johansson

Andreas Morstein

Antoine Carré

Joerg Kandler

Gerhard Westenberger

David Sohr

Olaf Claußen

Peter Fischer

Thomas Kaufhold

The present disclosure relates to a method for at least section-wise separating a glass element into at least two glass sub-elements along a separation face and a glass sub-element which is manufactured and/or can be manufactured in particular by the method according to the disclosure.

Method for separating a glass element and glass sub-element

A method is provided for determining the thermal expansion of a low thermal expansion material with very high accuracy of at most +/&#x2212;3 ppb/K or less and/or with a reproducibility of at most +/&#x2212;1 ppb/K or less. A measuring device is also provided that includes an advanced push rod dilatometer.

High-precision method for determining thermal expansion

The present invention relates to a precision component and also to a glass-ceramic which can be used for producing the precision component.

Precision component

The invention generally relates to manufacturing or providing of glass or glass ceramic products. The invention is based on the object to allow for providing glass or glass ceramic products having very accurately characterized thermo-mechanical properties. For this purpose, a deformation of the glass or glass ceramic material is measured at least twice as a function of time with different rates of change in temperature or a mechanical stress. Based on the measurements, relaxation times and weighting factors are determined by modelling. Then, based on the relaxation times and weighting factors related to the distribution of relaxation processes occurring in the product, a time-delayed change of a temperature-dependent or stress-dependent physical quantity, such as thermal expansion or refractive index, is calculated as a function of a predefined temperature change or stress change. The invention is used for selecting during manufacturing suitable glass products exhibiting selected time-delayed properties.

Method for determining time-delayed changes of temperature-dependent or stress-dependent physical quantities of a glass or a glass ceramic

A roller-equipped annealing lehr for flat glass, having a roller conveyor inside a lehr housing, with heating units arranged in pairs above and below the roller conveyor, in rows situated one after another and extending transversely to the feed direction. Temperature regulators are provided with predetermined desired values and actual temperature values that are measured in a position-dependent fashion. In order to achieve a desired stable temperature distribution and to prevent stresses in the flat glass, a feedback loop arrangement for at least one pair of heating units situated at a particular position in the row, presets as a control variable the heating output required to predetermine the temperature distribution in the region of this position as a predetermined portion of a heating output, which is calculated based on at least one actual temperature value measured at a different position in the row.

Roller-equipped annealing lehr

The method for producing single crystals includes drying crystal raw material by removing water, reaction of impurities with a scavenger, preferably a metal halide, and homogenizing the melt. The method is performed with the raw material in a melt vessel with a variable-sized through-going opening, in which drying occurs at 100&#xb0; C. to 600&#xb0; C. for at least 20 hours with a geometric conductance value for the through-going opening of 2.00 to 30.00 mm; the reacting occurs at 600&#xb0; C. to 1200&#xb0; C. for at least nine hours with a geometric conductance value of 0.0020 to 0.300 mmand the homogenizing occurs at above 1400&#xb0; C. for at least six hours with a geometric conductance value of 0.25 to 1.1 mm. Alternatively the geometric conductance value is the same during drying, reacting and homogenizing and takes a value between 0.25 and 1 mm.

Method and apparatus for purification of crystal material and for making crystals therefrom and use of crystals obtained thereby

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Armsheim, Germany

Clemens Kunisch