Soda-Lime Glass

Glass

Basics- Hard, brittle

Soda-lime glass

Process

-It is prepared by melting the raw materials. Eg. Such as sodium carbonate (soda), lime, dolomite, silicon dioxide (silica), aluminium oxide (alumina), and small quantities of fining agents in a glass furnace at temperatures locally up to 1675 degree Celsius.

-It is usually composed of 60-75% silica, 12-18% soda and 5-12% lime.

-It is process in two different methods such as float process for windows, blowing and pressing for container glass.

Technical information

-It has light transmission appropriate to be use in flat glass in windows.

-It has a smooth and nonporous surface.

-It is virtually inert and resistance to chemical attack.

-When glass is cut and has no edgework it is referred to as, clean cut.  Clean cut glass is used whenever the glass is installed in a frame and sharp edges are not exposed.

Limitations

-Can withstand the glass transition temperature for window at 564 degree Celsius.

-Hardness (Mohs scale) : 6

-Can be turn into any shape.

-Common use =3/32″- single strength (SS); for windows & picture frames.
                             1/8″ - double strength (DS); for windows & picture frames.
                             3/16″- for windows, small table tops .
                             1/4″ - for table tops, shelving.
                             3/8″ - heavy glass; for table tops, shelving.
                             1/2″ - heavy glass; for table tops, shelving.
                             3/4″ - heavy glass; for table tops, shelving.

Usage

-Used in residential window panes and glass bottles.

-Load-bearing structural glass.

-Modern glass art and light bulbs.

Environmental impact

-It uses common, easy to extract materials, the production process does not generate much waste, and the recycling ratios of glass are one of the highest of all materials.

Advantages

-It is the least expensive type of glass and most commonly use and reusable.

Disadvantages

-It is dangerous if it breaks. It might hurt as it turns into jagged shards.

-Easily loss of strength compare to tempered glass.

-It is not resistant to sudden temperature changes or high temperatures.

Company in Australia

-http://www.kkglass.com.au/Float.html

-http://www.helmaus.com.au/

Reference
-Materials for architectural design, By Victoria Ballard Bell with Patrick Rand
-http://www.lenntech.com/glass.htm

Tempered glass

Basics- Hard, brittle

-The manufacturing process heats the raw materials until they are completely fused, they are then cooled quickly become rigid without fully crystallizing.

Tempered glass = toughened glass

Process

-It is made by a process of heating annealed glass to 1200 degrees F (649 degrees C) and then quickly cooling it.

-Consider a type of safety glass

-Four to five time stronger than “normal” annealed glass.

Technical information

-It is float or plate glass that has been heated and rapidly cooled, increasing its inherent strength and ductility.

-It can have some distortions from the tempering process.

-Almost all large sheets of architectural glass are tempered, thereby reducing the required thickness of the glass.

-When designing with glass, they are three types of forces to consider = Tensile forces, compressive forces and shear forces.

Limitations

-Size limitations on diameter tempered= minimum of 11 ¼ diameter, maximum 60’’ diameter, maximum thickness is ½’’,

 Minimum tempered size 8*8 (non-diameter).

Usage

-Tempered glass is safer than regular types, it is ideal for use in car windows, shower and tub enclosures, doors,  display cases, and tabletops.

-Large sheet architectural exterior.

-For any other application that would become dangerous in the event of a human impact.

Environmental impact

-Tempered glass can be recycled but it is difficult to re-melt compared to annealed glass.

Advantages

-Chemical and corrosion resistant.

-It is suitable for windows that are exposed to high wind pressure or extreme heat or cold.

-Resistance to impact stresses

-Strength, which effectively resists wind pressure and impact, provides safety in many applications of tempered glass.

-Tempered glass can reach up to 24,000psi for breaking stress (large light 60 sec. load) compare to annealed glass which only can reach up to 6,000 psi.

-Tempered glass breaks in a unique way. If any part of the glass fails, the entire panel shatters at once. This distinguishes it from normal glass, which might experience a small crack or localized breakage from an isolated impact.

Disadvantages
-Tempered glass cannot be cut, drilled or altered after it is manufactured.

-It is much more expensive than annealed glass.

Company in Australia

-http://perthcityglass.rtrk.com.au/?scid=77857&kw=71117&pub_cr_id=6595552538

-http://www.kkglass.com.au/index.html

Reference
-Materials for architectural design, by Victoria Ballard Bell with Patrick Rand
-http://ezinearticles.com/?What-Is-Tempered-Glass?&id=2794691

-http://www.grayglass.net/glass.cfm/Flat-Glass/Tempered-Glass-/catid/1/conid/217