Characteristics of the product
Tempered glass is ordinary glass that has been processed by heat-treating method. The transformation procedure of transforming glass into tempered glass must be the last stage of processing as tempered glass is the unified piece of glass. This means that tempered glass contains line of force around the glass except the areas near the edges where line of force cannot reach. There is also forces from the interior pushing line of force equally. This cause the glass to be highly durable towards all actions ranging from pressing, crashing, to even being exposed to changes in temperature. The glass will break if line of force was destroyed, and the internal force will cause the whole glass to break into small pieces.
The process of producing tempered glass begins by bringing ordinary glass to undergo the process of heating until it reaches approximately 650 ºC, and the scorching glass will then be quenched by high-pressure air blast. The outer part of the glass will become stiff before the interior; consequently, molecules arrangement of the glass surface and the interior are different, creating tension in the glass. As a result of tension, two forms of forces are occurred: the first one is line of force surrounding the glass, and the other is interior force which will push out equally in all direction. This will generate the above-mentioned properties.
Any types of flat glass, regardless of different production—plate process, sheet process, and float process, can all be transformed into tempered glass as long as that particular glass contains suitable materials, e.g., no excessive amount of silver. Glass products producing from those procedures include clear glass, super clear glass, tinted glass (grey tinted glass, dark grey tinted glass, bronze tinted glass, and blue tinted glass). Pattern glass can also be used as a raw material if there is one smooth side, otherwise it will harm ceramic roller inside the furnace. (This is because glass in general except pattern glass is produced by float process. Thus, ordinary glass typically refers to those made from float process in particular.)
It is important to note that tempered glass cannot be processed further. Glass products from aforementioned production can be transformed via various procedures to contain more special properties before going to the tempering process.
Manufactured glass that can be transformed into tempered glass are satin glass, sandblast glass, ceramic coated glass, and etc. For special glasses including reflective glass, Low-E glass, self-cleaning glass, hydrophobic glass, and anti-reflective glass, only some of them can be tempered glass raw materials. Thus, consultation with a producer is required.
Mirror and color coated glass cannot be treated in tempering process, it is therefore necessary to proceed in tempered glass production before transforming into mirror or color coated glass.