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Glossary Of Terms / R-S

Glossary Of Terms / R-S Rub An abrasion or series of small scratches, which produce a frosted appearance, in glass generally caused during transport by a chip lodged between two panels. R - value The thermal resistance of a glazing system. The higher the R-Value the less heat is transmitted throughout the glazing material. The R-Value is the reciprocal of the U-Value. R-value is used by most other building materials and standards. Safety glass Glass which is treated or manufactured into a form that reduces the likelihood of cutting and piercing injury to persons by the glass should it be broken by human contact. These are the manufactured glass types which satisfy the requirements of AS/NZS 2208 for safety glazing. Laminated and toughened safety glass are rated grade A. Wired glass is rated grade B. Safety mirror Mirror which has a sheet of organic material permanently bonded to one side. The mirror holds together if broken and meets the test requirements of AS/NZS 2208. Refer to Vinyl Back mirror. Safety organic coated glass Glazing coated with a continuous film that meets the testing set out for grade A safety glass. Safety plastic A glazing material that is solid in its finished state. Plastic may consist of a single sheet of plastic material, a combination of two or more such sheets laminated together, or a combination of plastic material and reinforcement material in the form of fibres or flakes. It must meet the test requirements of AS/NZS 2208. Salt spray test Accelerated corrosion test in which samples are exposed to a fine mist of salt water. Primarily used to test silvered glass mirrors. Sandblasting The surface of glass is treated by blasting it with sand particles to obscure one or both surfaces of the glass. The effect is to increase obscurity and diffusion. It can make the glass weaker and harder to clean. Sash The separate frame to a window or door which carries the glass. It may be fixed (inoperable) or movable (operable). Screen printing The application of ceramic ink to the surface of glass through a screen or mesh. The ink may be applied uniformly to the entire surface or in a design determined by the mesh stencil. After screening the glass is toughened. 244 Product Catalogue For Glass Processors & IG Manufacturers

Glossary Of Terms / S Seaming Seaming refers to the process of grinding or sanding the sharp edges of cut glass, Security glass Thick laminated or multi-laminated glass designed to withstand various forms of violent attack. (Specialist advice should be obtained to assist in the selection of this product). Security glass Glass Polyurethane Polycarbonate Seeds Small gaseous bubbles in glass, normally less than 2mm in size. Selvedge The extreme side edges of the Lehr or glass ribbon during manufacture which are stripped off and recycled as cullet. Serviceability wind pressure The wind pressure that glass meets in normal conditions. This wind pressure is used to calculate deflections in the glass. Setting blocks Generally rectangular cured extrusions of Santoprene, EPDM or silicone, rubber or other suitable material. The bottom edges of glass are placed on these blocks to support the weight of the glass and avoid frame contact. Shading coefficient A traditional method commonly used in building façade energy evaluation is to consider the energy performance of a designed glazed area compared to the same area glazed with 3mm clear soda lime glass. It is referred to as an indicator of the “shading” performance of the glass design with respect to that of a 3mm glazing. The value is calculated by dividing the total energy transmittance by 0.87 and is specified using a value ranging from 1.00 to 0.00. Shark’s teeth Serrated features in the cut edges of glass. These extend from the score mark through part or all of the thickness. Shark’s teeth seriously weaken the edge and create thermal shock risk. Email: | Web: 245