Tempered Glass

Characteristics of the product

Insulated Glass is a type of glass that has spaces between glass which could be one or multiple spaces. These spaces result from using spacers to separate glass, it is therefore possible to look through like normal glass. The main purpose of insulated glass is to reduce heat transfer between indoors and outdoors. The most prevalent spacer used as the middle division is aluminium. An aluminium spacer will be formed with the hole in the middle, and the side that turn towards the space between the glass will have porous part to let the air flow between glass’ space and aluminium spacer’s.

The space of aluminium is a place for putting desiccant. When edges of insulated glass are closed, air will not be able flow in and out between the space inside the glass unit and external atmosphere. Desiccant will absorb humidity out of the air in the glass, letting the air to get dry. Dry air is a good insulator; hence, it enhances a thermal insulation property of insulated glass.

Being a high thermal conductivity material, using aluminium as a spacer will have a weakness for heat release. There are other kinds of spacer which are superior at heat insulation, however these alternatives are unpopular. This is because spacers should not only be adequately strong to handle with force reception and deflection of glass that can occur during the production, but price of spacers also should not exceed that of aluminium. Plastic is one of the examples that can be applied as the alternative.

All kinds of flat glass (float glass, tempered glass, heat-strengthened glass, laminated glass, reflective glass, Low-E glass, and self-cleaning glass) can be a part of insulated glass as long as that particular glass has less than 2 millimeters of deflection.

Having a capability in conducting heat less than dry air, inert glass can be a substitution of dry air in order to intensify thermal insulation properties. Argon is the most common inert gas for producing insulated glass.

The selection of various types of glass and gas will affect properties of glass in terms of thermal insulation, sound resistance, and tolerance towards crash and wind pressure. Superior property may come with higher price. In order to select the best value for money product and ensure the possibility of production and installment, a consultation between an owner, an architect, an engineer, a contractor, and a producer should be held.

Advantages

  1. Reduce thermal conduction between indoors and outdoors, helping to save energy as air conditioner works more efficiently.
  2. As two glass separated from each other, heat absorbed by the outer glass will radiate through dry air (thermal insulation). The internal glass will receive scant heat; those sitting nearby will feel comfortable for not getting heat from the radiation of glass.
  3. Reduce noise from outdoors.
  4. An allowance to increase durability of glass towards the breakage caused by heat, wind pressure, and smash by selecting suitable glass types for insulated glass.

Disadvantages

  1. Insulated glass is thick because of the air layer, and accordingly is difficult to lift and lay down due to the heavy weight.
  2. Based on insulated glass thickness, a supporting groove should be wide. Normal size of aluminium frame cannot be used in this case. The problem is an aluminium frame with an extra-wide glass supporting groove is costly and hard to purchase in Thailand.
  3. As insulated glass is the result of combining various types of glass together, this particular glass has high price.

Application

Due to the fact that tempered glass has a property resisting crash, press, and pressure and is less dangerous than other ordinary types of glass when broken, tempered glass is compulsory as a type of glass to use along with fitting equipment, e.g., frameless glass door set and shower door, rail preventing people from falling attached by fitting, and glass facade attached by fitting process.
For areas that have to handle with high smash or exposure to heavy wind—squash room, the wall separating between audiences and sport fields (such as basketball field), ice hockey field, and ice skating areas, tempered glass is essential as well. There are high chances of bumping into glass in crowded areas, thereby, the law determines the use of tempered glass in various places including department stores, banks, and car showrooms.
As tempered glass has unique properties in terms of resisting heat up to 290 ºC as well as tolerating to temperature changes up to 150 ºC, it can be used for spotlight lamp, fireguard for places near the fire, and the base for gas stove and hot pot support.
It is noteworthy that tempered glass is not resistant to fire, thus it is unsuitable for being used as a fire resistance material and a peephole for oven that temperature can go beyond 290 ºC.

Thickness

Thickness of glass that can be produced: 4, 5, 6, 8, 10, 12, 15, 19 millimeters

Smallest

The smallest size that can be produced: 180 X 180 millimeters or with longer than 250 millimeter for diagonal

Largest

The largest size that can be produced: 2,800 X 6,000 millimeters

* Remark: The size of thin glass depends on raw materials; hence, please inquire about the size before ordering.

Caution in use

  • Tempered glass cannot be cut, pierced, and chipped off after the production.
  • Measuring areas carefully is therefore necessary, and we encourage to use the unit of ‘millimeter’ for an accuracy. Allowing it to be slightly loose will enable to install glass easier, yet it should not be too loose to slip out of glass moldings.
  • A single piece of tempered glass should not be used for making a roof or a wall of high-rise buildings as it is possible to fall over in case glass is broken.
    A single piece of tempered glass should not be applied for floor making, pedestrian areas, or staircase as people can fall down immediately when the glass is broken, and it can harm people down there as well.
  • Tempered glass cannot be used as a substitution for fire-proof glass since tempered glass cannot resist fire and provide safety for residents according to the restriction of fire-proof.

The way to detect a tempered glass

In terms of visual property, it difficult to distinguish tempered glass from ordinary glass. Noticing waves can differentiate them in case raw materials are float glass. Unfortunately, this method is not effective in case of plate glass and sheet glass. This makes it complicated for customers to perceive whether the received glass is the tempered glass or not.
For certain detection, smashing glass to examine whether the glass breaks into small pieces or not is required, nevertheless this will cause to the waste of that glass. If not smashing the glass, special instrument (Laser GASP) can be used for observing tension of the glass to see whether it is a tempered glass or not. In fact, this instrument is expensive, and accordingly is typically used by glass factories only.
There is normal equipment, polaroid film, available at science equipment shops that can be used for detecting whether that particular glass was produced through heat treating process or not. The means to detect is to bring one sheet of polaroid film and place it at the back of a glass at the edge of the glass (there may be a part of the film outside the glass), following by placing another sheet of polaroid in front of the glass in order to look pass to the polaroid film at the back. In case rotating the polaroid film in front of the glass, it is possible to see the glass ranging from the least brightness up to nothing. This is because polaroid film at the back would cut light wave out in a single plane. The light that comes through would be cut out by frontal polaroid. If the plane of light that is cut out is perpendicular, there will be no light getting through. While rotating polaroid film, you could see black brownish line in parallel with the glass brim. Thin glass tends to have the parallel line nearer to the glass brim compared to thick glass. For glass with the same thickness, the glass that parallel line is closer to the glass brim has higher tension, yet this method cannot state whether the glass is a tempered one or heat-strengthened glass.