Types Of Glass

Fitting Window Panes Since the 1950s, from the first incarnation of the standard glass window production that we know today, there is a huge variety of glass types now in production that can be applied to domestic, commercial and industrial properties, both inside and out. Sir Alastair Pilkington's innovative production method of float glass has since been adapted to meet the demands of modern buildings and environmental concerns in numerous ways. However, 90% of flat glass is still fabricated by the principles of float glass production as Pilkington originally conceived.

For a glass window or glazing product that achieves that little bit extra, outlined below are some of the high tech glasses currently in production.

Alarm glass:

This is a security glass that is specially laminated with a wire of 0.1mm between the sheets of glass. The wire is part of an electrical circuit that triggers the alarm if the glass is damaged, and is therefore ideally suited to secure commercial or industrial premises.

Anti reflective glass:

Handle Glass Safely Standard float glass undergoes a dipping process that coats it with metal oxide layers. The result is that it reflects a low percentage of light, but still allows for clarity and transparency. Anti reflective glass is great for use in places such as a building with a wall of glass keeping the visuals clear, it also increases the glass sheets durability.

Body tinted glass:

During the float glass melt process chemical colorants can be added which tint the colour and increase absorption from the sun. This helps minimise the solar radiation that enters a building, keeping it cooler inside and protecting furnishings from fade. Body tint glass is great for those that want a unique looking building because it's possible to have the glass made in many different shades.

Electrochromatic glass:

Also known as Smart Glass, Suspended Particle Displays (SPD), electrified liquid crystal, thermotropics, photochromics or photochromatics. This smart glass aims to reduce the need for blinds and curtains as it can change with the amount of light reducing the amount allowed to pass through when the sunlight intensifies. It contains an electric current that can be manually turned on or is that automatically responsive to the light.

The intensity of the sunlight triggers a low voltage current which charges a minutely thin coating on the surface of the glass. This causes the electrochromatic layer to gradually change from light to dark. This highly beneficial for glass buildings as it reduces cost and awkwardness of window coverings and reduces the solar heat and UV radiation.

Fire resistant glass:

There are two main types of fire resistant glass, each designed with their own benefits:

1. Heat transmitting - This incorporates wired glass and reinforced laminated glass which offer protection against flames and inflammable gases, but only for a short while. It does not prevent heat being transferred to the other side of the glass, so it will be hot to touch.

2. Fire insulating - This glass is capable of a longer containment period of flames, gases and smoke, and also prevents heat transmission to the other side of the glass.

Float glass:

Standard flat, clear window glass is called float glass; named after the manufacturing process that creates it.

During production, soda lime glass, calcium, silica sand, soda, oxide and magnesium are mixed together and melted in a furnace at a temperature of around 1500°C. The molten glass is then poured into a molten tin bath. The tin is fluid but the glass is still viscous, so they do not mix and instead stay flat like the contact surface between them. The glass partially cools, and is then put into a lehr (annealing chamber), where it undergoes a controlled cooling process until it reaches room temperature.

Laminated glass:

Another kind of security glass is laminated glass this is secure in the way that when someone tries to break the glass because there is a sandwich effect from the glass between PVB or resin it holds together when forced. This coating over the glass means when it is hit it may crack but the pieces are held together preventing splinters of glass. For this reason it is also installed to delay the spread of fires.

Bay Window Seat

Reflective glass:

Starting with float glass, a metallic coating is added that serves to minimise the solar heat that passes through. The metallic coating has a mirror effect, and so reflects back the light and prevents passers by seeing into the building and also prevents some of the heat from passing through. It is used mostly in building facades, and is produced in one of two ways:

1. Pyrolitic (on line) - During the float glass process, semi conducted metal oxides are adhered to the glass while it is still hot in the annealing lehr. Unfortunately, these hard coatings are quite harmful to the environment.

2. Vacuum/magnetron (off line) - Metal oxide layers are applied to the glass under a vacuum. This is a soft coating, and as with the soft coat low E glass it is sensitive to harsh conditions. It must therefore be used on the inside of the glass.

Tempered glass:

Tempered or toughened glass undergoes a different manufacturing process to normal glass, this glass is designed to be around 3 times as strong as normal glass. As soon as the glass is removed from the furnace, it receives a continuous and uniform air quench, where air is blown across it to cool it to a temperature of around 400 - 600 °F and thus causing the material to harden. The tempered glass is then fit for security applications. Tempered glass is tougher to break than ordinary glass, and when broken just shatters into small fragments that avoid causing major harm.