Glass Quality and Specification of Curved Panels

Glass distortions may cause objects to appear irregular and out of focus when observed through a distorted glass panel. Any visual disturbance, such as roller waves, bow, warp etc., should be within the tolerances given in the appropriate standards or manufacturer limits. These standards and limits generally describe how distortions may be measured for a flat panel but cannot be applied to curved panels due to a combination of curvature tolerances and unclear shaped distortion defects. Quantifying visual distortions in curved glass panels is a challenging task, but not impossible according to the automotive and aerospace industry, where distortions may cause visual misjudgment and safety concerns. It is desirable to extrapolate the knowledge of assessing the quality of curved glass panes to the building industry in order to set limits on what is visually acceptable. Therefore, this paper aims to introduce several methods to capture the visual distortions, quantify the results and define acceptance criteria that can be used to assess curved glass panels in the building industry.