ENKELTLAGET HAERDET SIKKERHEDSGLASPLADE TIL ANVENDELSE SOM SIDE- ELLER BAGVINDUE TIL ET KOERETOEJ

摘要

Thermally toughened glass sheets of thickness 2.5 mm to 3.5 mm, for use as motor vehicle side or rear windows, are produced by differential quenching producing a distribution of regions of more highly toughened glass interspersed with regions of lesser toughened glass. The average central tensile stress is in the range 62 MN/m2 to 53 MN/m2, and there is a distribution of areas in which the principal stresses acting in the plane of the glass sheet are unequal. The principal stress difference in some of the areas is at a maximum in the range 8 MN/m2 to 25 MN/m2, the major principal stresses in adjacent areas in which the principal stress difference is a maximum are in different directions, and the distance between the centers of such adjacent areas is in the range 15 mm to 30 mm.