Architectural-Glass Coating

Conversely, in the summer, it would still have a high transparency for the visible, but a high reflectivity for the near infrared and a high emissivity for the far infrared. The present state of the art of thin-films deposition still falls short of this goal which may have to wait for the development of suitable photochromic coating materials. 

Winter characteristics of coating Transparent to visible and near IR - Reflective to tar IR 

6mm CItar Class with Solar Control Coating 

the other major deposition process, is used on a large scale. A typical low-E glass is obtained by depositing a thin film of silicon dioxide followed by another thin film of fluorine-doped tin oxide. The Si02 acts as a diffusion barrier and the Sn02 reduces the emissivity. A typical CVD apparatus is shown in Fig. 

These films are deposited at atmospheric pressure on the hot glass in a continuous operation (float-glass process). The CVD reactions are described in Ch. 11. 

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Figure 16.5. Performance of present architectural-glass coatings.

Optically Functional. Laser optics, layer architectural glass panels (up to 3 x 4.3 m), lenses, TV-camera optical elements, and similar apphcations require optically functional coatings. 

Most AR coatings are still produced by evaporation but CVD is gradually introduced particularly in applications with three-dimensional surfaces or deep recesses. AR coatings are used in numerous applications, which include lasers, lenses for cameras and binoculars, instrument panels, microscopes, telescopes, range finders, etc., as well as on automotive and architectural glasses. 

Figure 16.4. Ideal characteristics of optical coatings for architectural glass.

Indium-tin oxide (ITO) is indium oxide doped with tin oxide. Thin films of ITO have commercially valuable properties it is transparent, electrically conducting and reflects IR radiation. Applications of ITO are varied. It is used as a coating material for flat-panel computer displays, for coating architectural glass panels, and in electrochromic devices. Coating motor vehicle and aircraft windscreens and motor vehicle rear windows allows them to be electrically heated for de-icing... 

As an example. Figures 5.32-5.34 show the soiling and cleaning behaviour of standard materials for textile architecture PVC-coated PET fabric, PTFE-coated glass fabric and silicone-coated glass fabric. Before and after... 

Transition metal sol-gel chemistry has successfully been applied since more than 30 years in the form of titania coating on architectural glass, produced by the Schott Gompany in Germany [138]. A smooth and dense Ti02 anatase film was prepared, using the sol-gel techniques and subsequent heat-treatment at a temperature of450-500°G [139-145]. 

Coade Stone. A vitreous ware, used for architectural ornament, made in London by Mrs Coade from 1771 until her death in 1796 manufacture finally discontinued in about 1840. The body consisted of a kaolinitic clay, finely ground quartz and flint, and a flux (possibly ground glass). Coated Dolomite Grain. Also known as unfired semi-stable dolomite refractory, this comprises calcined dolomite bonded with tar or oil. 

TABl 18-1. COMPARISON OF THE COATING METHODS FOR AN ARCHITECTURAL GLASS... 

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