Abstract: In a method and apparatus for marking glass or a glass-like material a writing laser beam and the glass or the material are moved relative to each other in order to form an array of marks on the glass surface or material surface consisting of a plurality of discrete marks which are formed in discrete marking steps and are distributed along at least one direction. Marks directly adjacent to each other in a predetermined direction are formed in two marking steps, which are not carried out directly in succession one after the other. Thus, at least two series of marks are produced in the predetermined direction, wherein said marks are spaced at regular intervals from each other and are interleaved in the predetermined direction. As a result, and because of the temperature regime according to the invention during encoding, a particularly low-stress, crack-free marking of glass can be accomplished.

Abstract: In a method and apparatus for marking glass or a glass-like material a writing laser beam and the glass or the material are moved relative to each other in order to form an array of marks on the glass surface or material surface consisting of a plurality of discrete marks which are formed in discrete marking steps and are distributed along at least one direction. Marks directly adjacent to each other in a predetermined direction are formed in two marking steps, which are not carried out directly in succession one after the other. Thus, at least two series of marks are produced in the predetermined direction, wherein said marks are spaced at regular intervals from each other and are interleaved in the predetermined direction. As a result, and because of the temperature regime according to the invention during encoding, a particularly low-stress, crack-free marking of glass can be accomplished.

Abstract: The method measures the thickness of a hot glass body without direct contact with the glass body and is based on chromatic aberration. This method includes focusing a light beam from a light source on the hot glass body using a focusing device immediately after formation; conducting reflected light from the glass body into a spectrometer to obtain a reflected light spectrum; finding two wavelengths of the reflected light from the front side and the rear side of the glass body respectively at which reflected light intensities are maximum; determining the thickness of the glass body from the difference between the two wavelengths; maintaining the focusing device at a temperature below 120° C. during the measuring of the thickness and substantially preventing heat radiation from reaching the focusing device using at least one heat-blocking filter.

Abstract: The invention relates to a method for treating refractory material which consists of fireclay, light-weight refractory bricks, silimanite bricks, zirconium and zirconium-containing bricks, and fusion-cast bricks with compositions from Al2O3, SiO2, ZrO2 and/or MgO or CrO in order to render it corrosion-resistant so that it withstands contact with a glass melt for a longer time. The surface of the material is treated by laser radiation, forming a vitreous surface layer having a thickness of 100 to 1000 ?m.

Abstract: The method measures the thickness of a hot glass body without direct contact with the glass body and is based on chromatic aberration. This method includes focusing a light beam from a light source on the hot glass body using a focusing device immediately after formation; conducting reflected light from the glass body into a spectrometer to obtain a reflected light spectrum; finding two wavelengths of the reflected light from the front side and the rear side of the glass body respectively at which reflected light intensities are maximum; determining the thickness of the glass body from the difference between the two wavelengths; maintaining the focusing device at a temperature below 120° C. during the measuring of the thickness and substantially preventing heat radiation from reaching the focusing device using at least one heat-blocking filter.

Abstract: The invention relates to a method for cutting glass tubes, characterised by the following steps: a glass strand is drawn; a heating device is driven synchronously with the glass strand and is directed towards the region of a desired separation point; the glass strand is drawn in the region of the desired separation point; a separation device is driven synchronously with the glass strand; the separation device is actuated in such a way that it severs the glass strand at the desired separation point.

Abstract: In an apparatus and a method for marking glass with a laser, the glass is first brought to a temperature above the transformation temperature of the glass. The glass is then acted upon by a laser pulse which produces a mark on the surface of the glass. The peak power of the laser pulse is preferably selected so that it is merely a thermal interaction with the glass surface which occurs. This has the advantage that the material properties of the marked glass remain unchanged compared with the unmarked product.

Abstract: A process is described for producing a desired breaking point for breaking the glass wall of a glass body, in particular a break-open ampule or a tube, or for separating parts out of a pane of glass by generating microcracks in the breaking zone, in which process the microcracks are generated in the interior of the glass wall or the pane of glass.

Abstract: Disclosed is a method for the heat-softened severance of thin-walled glass tubes or plates with a wall thickness of no more than 0.2 mm, wherein the glass is softened on a width of no more than 0.4 mm, the softened area is reduced by drawing to a wall thickness of no more than 0.05 mm, and then is separated by additional heating in the drawn-out area.