GLASS

What is Glass?

• Glass is a hard material normally fragile and transparent common in our daily life. It is composed mainly of sand (silicates, SiO2) and an alkali.
• These materials at high temperature (i.e. molten viscous state) fuse together; then they are cooled rapidly forming a rigid structure.
• Glass is used for architecture application, illumination, electrical transmission, instruments for scientific research, optical instruments, domestic tools and even textiles.

Characteristic of glass 
 
• Solid and hard material
• Disordered and amorphous structure
• Fragile and easily breakable into sharp pieces
• Transparent to visible light
• Inert and biologically inactive material.
• Glass is 100% recyclable and one of the safest packaging materials due to its composition and properties


Float glass

• Float glass is produced by floating a continuous stream of molten glass onto a bath of molten tin. The molten glass spreads onto the surface of the metal and produces a high quality, consistently level sheet of glass that is later heat polished.
• The glass has no wave or distortion and is now the standard method for glass production and over 90% of the world production of flat glass is float glass.
• Float glass can be cut using a glass cutter and no special equipment is necessary.
• Float glass is suitable for fixed and opening windows above waist height.




Strengthened glass

Fully Tempered Glass  

• Fully tempered glass is produced by heating float glass and then suddenly cooling it with special blower. 
• Tempered glass is four to five times stronger than standard glass and does not break into sharp shards when it fails.  
• Cutting and drilling fully tempered glass will destroy the integrity of the skin’s compressive strength and will likely cause breakage, therefore fully tempered glass cannot be field-cut. 
• Fully tempered glass must be fabricated with the required holes or cutouts. It is available in thicknesses from 3 to 25mm.

Heat - Strengthened glass  

• Heat Strengthened glass manufacturing process is similar to that of fully tempered except that the glass is on partially tempered. 
• Heat Strengthened glass is not a fire-rated glass product.  
• The color, clarity, chemical composition and light transmission characteristics of glass remain unchanged after heat strengthening. 
• Heat Strengthened glass tends to break into large fragments, similar to annealed glass. 
• Heat Strengthened glass can not be used in hazardous locations as defined by law or building code, or where human impact is a concern. 
• Heat strengthened glass can not be cut or drilled, sandblasted or etched, or edge polished or ground. Any fabrication or field alteration will weaken or break the glass. 
• When tempered glass breaks, the resulting small pieces tend to vacate the framing system under lateral load.

Laminated glass

• Laminated glass consists of two or more pieces of float glass bonded together with a clear layer of PVB (polyvinyl butyral). 
• The process combines heat and pressure to bond the layers together into one. 
• This product is favored for protection in high security areas for its retention in the frame when broken and for its sound reduction quality when combined with different thickness of glass. 
• When subjected to stress, laminated glass ruptures with a pattern similar to annealed glass with large shards, however the PVB inner layer holds the shards together. 
• Annealed, fully tempered, heat-strengthened and wire glass types can be laminated.

Advantages Laminated glass
• Security
The standard two-ply construction provides resistance to penetration when subjected to attempted force entry. In multi-ply configurations, laminated glass can even resist bullets, heavy objects, or small explosions.

• Sound Control
The shear damping performance of the PVB makes laminated glass an effective sound control product.

• Solar Energy Performance
The PVB in laminated glass helps reduce solar energy transmittance to reduce cooling loads

• Ultraviolet Screening
The ultraviolet (UV) filtering performance of the plastic interlayer helps protect valuable furnishings, displays or merchandise from the fading effects of UV radiation.

Wire Glass

• Wire glass has wire mesh or parallel wires rolled into the center of the glass sheet, it s available in various pattern sizes such as clear wire square mesh, clear wire diamond mesh and hammered wire diamond mesh.
• If breakage occurs, the wire helps to hold the glass fragments in the opening, thus preventing personal injuries.
• This the standard glass type used for fire-rated doors or partition assemblies.

Tinted glass

• Tinted glass refers to any glass that has been treated with a material such as a film or coating, which reduces the transmission of light through it.
• The tint in the standard production of float glass adds glare reduction and a heat reducing feature to the window.
• The standard tints available are green/blue, gray and bronze.
• Most laminated glass such as heated glass and fire-rated glass is available in a larger selection of tints.
• This glass type offers the maximum UV protection.


Low-Emissivity Glass

• Emissivity refers to the ability of a surface to absorb or reflect heat. An energy efficient glazing technology, Low Emissivity glass is a poor absorber of heat. 
• Low-emissivity glass (Low-E) was developed to address energy efficiency concerns for glazing. 
• Hard or soft coating are applied to the glass based on application type. 
• Low-E coatings provide more reflectivity for the shortwave solar energy that strikes the glass at a high angle of incidence during the summer , while permitting this warmth to enter during the winter when the angle of incidence is lower.  
• Low-E coatings are applied to side 2 on the first pane of glass in a double-glazed unit. The overall light transmission rate is higher than in tinted and reflective glass type 

clear glas

Low-E