Abstract: The invention relates to an object containing at least one glass spacer between a first element of said object and a second element of said object, said spacer having a concentration gradient in alkali metal ions from its surface and perpendicular to its surface. The object may be a solar collector under vacuum. The invention also relates to a glass bead having a concentration gradient in alkali metal ions from its surface and perpendicular to its surface and its use as a spacer withstanding a pressure force between two elements, said pressure pushing the two elements together.

Abstract: A method for cutting a glazing unit without applying a breaking force. The method applies a treatment to the glass sheet that generates stresses with a biaxial distribution, the stresses being such that the K factor is between 0.05 and 0.4 MPa·m1/2; the K factor being defined by K=[??z2·H(?z)·dz]1/2 in which z is a position in the thickness, ?z is intensity of the approximately isotropic biaxial stress at the position z, H(?z) is equal to 1 if ?z is greater than 0 and is equal to 0 if ?z is less than or equal to 0, with the convention that extension is denoted by positive values and compression by negative values. A subcrack deeper than 10 ?m is scored along the desired line of cutting, the subcrack reaching that region of the glazing in extension. The method allows cutting of glass, without breaking it, along curves with a small radius of curvature, or of glass strips of width similar to the thickness, or of frame shapes used as inserts in a flat field emission display.