Glass & Ceramics

Glass & Ceramics Interior Design Materials Interior Haval Sami Ali [email protected] Glass • Glass and ceramics are related materials, and glass is sometimes considered as no crystalline ceramic. • Clay-based ceramics are the most commonly used in interiors. GLASS • Glass is a hard, brittle substance made by melting silica (typically from sand) with other materials such as soda ash and limestone at very high temperatures . When cooled, the atoms are locked into a random state before they can form a perfect crystal arrangement. • This amorphous structure is responsible for the transparency of glass and its ability to be blown into a bubble or pulled and twisted when molten. Properties • glass seems hard and rigid, it is elastic and will bend or stretch when force is applied, then return to its original position. Glass is stronger in compression than in tension and breaks from tensile forces. • Tempering increases the strength of glass. The production of tempered glass involves heating and then rapidly chilling the glass to put all its surfaces into compression. • Glass is highly resistant to corrosion. • The ability of glass to resist the passage of electricity makes it useful in the electronics industry. • Glass is transparent, transmitting most of the light that falls on it . • Glass that absorbs infrared wavelengths and transmits visible ones blocks heat while transmitting visible light Types of Glass • Approximately 90 percent of glass made today is inexpensive soda-lime glass composed of silica, soda, and lime. Float glass is used in the production of annealed, tempered, and laminated glasses. • Float glass is the most common method of making flat, clear glass today. • The process involving floating molten glass on a surface of molten lead (now tin) was introduced in 1959 by Alastair Pilkington. • • Crown glass was blown as a sphere and spun into a disk in a process that produced distortion lines in concentric circles . The thinnest, clearest glass was cut from the edge of the disk and used for windows. Annealed glass • is reheated and slowly cooled under controlled conditions to reduce internal stresses that could lead to shattering. Annealed glass can be cut or drilled on-site after manufacturing. It shatters into sharp shards, and is not considered to be safety glass or approved for use in fire-rated assemblies. Tempered glass • Tempered glass is produced by heating annealed glass to 1200°F (650°C). The outer surfaces are then rapidly cooled, putting them in high compression. • Tempered glass is stronger than annealed glass and more resistant to impacts and temperature variations. It breaks into many small fragments. • however, cutting, drilling of holes, and grinding or polishing of edges must be done before tempering. • Tempered glass is used for tabletops, sliding doors, building entrances, and bath and shower enclosures. It is designated as safety glass but is not approved for use in fire rated assemblies Heat-strengthened glass • Heat-strengthened glass is annealed glass that has been partially tempered. It will break into sharp shards. Heat strengthened glass is about twice as strong as annealed glass, and is often used in architectural applications, but is not approved for use in fire-rated assemblies. Laminated glass • Laminated glass consists of two or more layers of glass bonded together with a sheet of plastic . • When broken, the glass shards are held in place by the plastic sheet. • When made from annealed glass, laminated glass can be cut and worked after it is manufactured. • Laminated glass is used for storefronts, balconies, stair railings, and roof glazing. • Security glass Wired glass • Wired glass comprises steel wire mesh sandwiched between two layers of semi-molten glass. When broken, the mesh retains the pieces of glass. Wired glass is approved for use in fire- rated assemblies; however, it is not considered to be safety glazing Textured glass • Textured glass is produced by pressing a sheet or ribbon of molten glass between two rollers, one (or both) of which carries a pattern. Textured glass is available in many patterns, including bubbles, reeded (concave curves), and ribbed Table : Slumped and Fused Glass Products Type Description Slumped glass Softened in kiln to slump into mold with textured surface one side, smooth on other. Partitions, reception desks, water features, doors Bent glass Slumped glass that sags to shape of supporting mold. Storefronts, elevators, walls, display cases, showers Corrugated glass Glass formed into 3-D waved contour. Feature walls and divider panels Fused glass Multiple layers fused together. Furniture, borders, tiles, panels, light fixtures Technical Glass Products • There are many types of architectural glass designed to meet specific technical requirements. Type Description Body tinted glass Colorants added to clear float glass affect tint and solar radiation absorption. Partitions, balustrades, mirrors Fire resistant glass Proprietary fire-rated products; some are safety rated Privacy glass Technical switchable glazing for privacy, solar glare, and (smart glass) heat gain reduction, sunlight diffusion Antireflection glass Coating on float glass reduces surface reflection and increases light transmittance. Storefronts, picture framing, display cabinets, and windows Manufacturing Glass • The three categories of materials used to make glass are formers, fluxes, and stabilizers. • Silica, found in sand, is the most common former. • Fluxes such as soda ash are used to melt formers at lower temperatures. • Stabilizers such as limestone increase the stability of the glass. Environmental Impacts of Glass • The basic material for most glass is sand consisting primarily of quartz granules, which is readily available and nonpolluting. • Recycled glass production uses less energy and produces fewer emissions to manufacture than new glass. • Due to the high temperatures required to melt and refine glass, the embodied energy level of glass is quite high, • Flat glass is at the lower end, laminated glass somewhat higher, and tempered glass the highest. • The production of glass is fueled by natural gas or oil, producing substantial CO2 emissions. • Glass materials are delivered either as powders or fine grains. Dust control systems are difficult to maintain and escaped dust is often a problem. Applications of Glass Transparent Wall Units • Transparent wall units are an assembly of various materials including glazing products to produce a transparent, fire resistant, and sometimes self- supporting unit. An inert material that turns to a foam when exposed to heat is typically used between two glazing components to provide fire resistance. Cast Glass Blocks and Pavers • Cast glass is used to produce glass blocks for walls and partitions that are not load-bearing. • Glass stairs can be made of laminated glass, either annealed or tempered, with a polymer interlayer. • Glass flooring, typically in panels of 10.8 square feet (one square meter), are available clear or colored. • Glass pavers are cast as single layers or as hollow blocks. Clear and textured nonslip surfaces are available. Precast panels are also available. Glass Tiles • Greek, Persian, and Indian artisans made glass tiles as early as the third century BCE. They are durable and impervious to water, • Handcrafted glass tiles are typically made with a high percentage of recycled material Mirrors • A glass mirror is made by adding a reflective coating of silver backed with copper and paint. • Transparent (two-way) mirrors utilize reflective glass made with pyrolytic and vacuum deposition coatings. They permit vision through in one direction while appearing to be a standard mirror from the other; this requires a lower light level in the viewing room..

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