An insulating element for thermal isolation includes a vacuum cell having a wall with a corrugation.

Provided is a sleeve for glass tube molding capable of suppressing generation of foreign matter such as rust from a sleeve shaft and suppressing adhesion of foreign matter such as rust to the molten glass without degrading mechanical strength of the sleeve shaft. A sleeve for glass tube molding includes a sleeve shaft including a through-hole and a refractory cylindrical body inserted coaxially with the sleeve shaft around the sleeve shaft. A superior rust-resistant material having rust resistance superior to that of the sleeve shaft is provided to cover a part or whole of an inner surface of the through-hole of the sleeve shaft and to cover a tip of the sleeve shaft.

A laminated or single layer glass cylinder and its method of making are disclosed. The laminated cylinder glass is a precursor component to enable making subsequent drawn tubing having high optical quality. The laminated cylinder glass may comprise a first layer of glass as a clad glass and a second layer of glass as a core glass. The second layer of glass may be bound to the first layer of glass. The second layer may have a higher CTE from about 5×10.sup.−7/° C. to about 100×10.sup.−7/° C. than the first layer of glass. The first layer and second layer of glass may have different softening points within about 200° C. of each other. In some embodiments, the first layer and second layer of glass may have different softening points from about 50° C. to about 200° C. of each other.

An apparatus for forming glass tubing is described. The apparatus for forming glass tubing comprises an endless former with an outer surface and an inner passage defining an inner surface. The apparatus for forming glass tubing further comprises two chambers from which molten glass may flow. One chamber flows molten glass to the outer surface of the endless former and another chamber flows molten glass to the inner surface of the endless former. The two flows of molten glass meet at the bottom of the former to form glass tubing.

The present invention is directed to methods for making high quality glass tubes, and apparatuses for making high quality glass tubes. Because glass tubes made using the methods and apparatuses disclosed herein are substantially free from the optical defect known as paneling, the glass tubes may be used in displays for consumer electronic devices. The glass tubes are made by a continuous process in which a flow of molten glass is provided on an inner surface of a hollow, rotating mandrel such that the glass coats the inner surface of the mandrel and flows downstream on the inner surface of the mandrel, during which it is cooled to provide a higher viscosity. The glass is then removed from the mandrel and drawn to obtain a glass tube. A flow of molten glass may also be provided on the outer surface of the mandrel and joined with the glass flow on the inner surface of the mandrel when the glass flows exit the mandrel. The apparatuses presented herein are configured to provide high quality glass tubes using this method.

Methods for producing glass articles from laminated glass tubing include introducing the glass tubing to a converter. The glass tubing includes a core layer under tensile stress, an outer clad layer under, and an inner clad layer. The methods include forming a feature the glass article at a working end of the laminated glass tubing and separating a glass article from the working end of the laminated glass tubing, which may expose the core layer under tensile stress at the working end of the glass tubing. The method further comprises remediating the exposed portion of the core layer by completely enclosing the core layer in a clad layer. Systems for re-cladding the exposed portion of the core layer as well as glass articles made using the systems and methods are also disclosed.

A method of making a glass sheet comprises laminating a high CTE core glass to a low CTE clad glass at high temperatures and allowing the laminate to cool creating compressive stress in the clad glass, and then ion exchanging the laminate to increase the compressive stress in the outer near surface regions of the clad glass. The core glass may include ions that exchange with ion in the clad glass to increase the compressive stress in inner surface regions of the clad glass adjacent to the clad glass/core glass interfaces. The glass laminate may be formed and laminated using a fusion forming and laminating process and fusion formable and ion exchangeable glass compositions.

Methods for producing glass articles from laminated glass tubing include introducing the glass tubing to a converter. The glass tubing includes a core layer under tensile stress, an outer clad layer under, and an inner clad layer. The methods include forming a feature the glass article at a working end of the laminated glass tubing and separating a glass article from the working end of the laminated glass tubing, which may expose the core layer under tensile stress at the working end of the glass tubing. The method further comprises remediating the exposed portion of the core layer by completely enclosing the core layer in a clad layer. Systems for re-cladding the exposed portion of the core layer as well as glass articles made using the systems and methods are also disclosed.

A method of making a glass sheet comprises laminating a high CTE core glass to a low CTE clad glass at high temperatures and allowing the laminate to cool creating compressive stress in the clad glass, and then ion exchanging the laminate to increase the compressive stress in the outer near surface regions of the clad glass. The core glass may include ions that exchange with ion in the clad glass to increase the compressive stress in inner surface regions of the clad glass adjacent to the clad glass/core glass interfaces. The glass laminate may be formed and laminated using a fusion forming and laminating process and fusion formable and ion exchangeable glass compositions.

A method and a device for encasing gemstones, such as diamonds, in glass. In order for their optical effects and appearance to be maximized, the gemstones are placed at a defined position and at a defined orientation. A suction cannula is provided for that purpose with an opening to fit the gemstone and to hold the gemstone by vacuum. Guide elements, such as spirals or meshes, are carried on the suction cannula so as to assure even distancing from the walls of the glass tube into which the gemstone is inserted.