Float Glass: 

Float Glass is the most basic type of glass produced and its origins goes back to as far as 7000 BC, where glass objects are found in Egypt and Mesopotamia. Egyptians around 1500 BC seem to have been the first people to realize what could be done with glass when heated while the first manual of glass manufacturing appeared some millennials later. 

Float Glass is certainly one of the most interesting processes of the twentieth century. The industrial float process is one of the most widely used methods for glass manufacturing as it ensures security, high quality, and productivity. From a historical point, this innovation was the beginning of a revolutionary change in the mass production of float glass for the building and automotive sectors. More specifically this innovation eliminated the traditional operations of rolling, grinding, and polishing the glass surface – which also were not safe – while creating high-quality and inexpensive flat products. The first patent was applied for on December 10th, 1953.

Composition and Production

Float glass is made by pouring the molten glass from a furnace inside a chamber that contains a bed of molten tin. The process is called the Pilkington Process. The atmosphere inside the chamber is carefully controlled so the glass can float on the bed and forms itself in the shape of the container, being called FLOAT Glass

Float glass is composed of silica sand, limestone, dolomite, and soda ash among other materials heated to 1,600 °C. Next, the molten liquid is poured into a tin bed that floats the liquid down a line and forms the liquid into the glass at the dimensions specified. The method provides a controlled thickness and goes through controlled cooling processes that create Annealed Glass.

The upper surface of the glass is called the airside or score side an is polished with fire. The lower surface is called the tin side. It is not fire-polished. From the chamber, the glass enters an oven, called a lehr. Inside lehr it is slowly cooled to a specific rate. This process, called annealing, relieves the glass of internal stresses. The rate of cooling is crucial to the success of the final product. The glass emerges from the lehr at room temperature as a continuous ribbon. It is flat, fire-finished on the top, and has smooth, parallel surfaces. Automatic cutters trim the edges and cut the glass to length.

Clarity of Float Glass

Low iron glass is composed of silica and other materials while throughout the manufacturing process at least 90% of the iron is removed to ensure the clearest glass is produced. High iron glass tends to have a greenish tint as it reacts different to reflection of light. The higher the amount of iron, the greener the color of the glass tends to be green. A relative classification for Iron Content and Clarity has been commonly used categorizing Clear Float glass to Clear Glass, Super Clear Glass, and Ultra Clear.

Generally, there are two types of Float Glass Product:

 1- Clear Glass:

Most of the flat glass made by the float process is clear glass. As its name implies, clear glass is transparent and colorless. Depending upon its thickness and it allows about 75 to 92 percent of the visible light to pass through.

2- Tinted Glass (also called heat absorbing glass):

Tinted Glass is made by adding coloring agents to the batch mix. These agents include bronze, gray, green, and blue. As the glass becomes thicker, the density of the color also rises which causes the glass to transmit less visible light. The light transmittance of tinted glass varies from 14 to 83 percent depending upon its color and thickness and production method.

Supply of Iran Float Glass

Iranian Float Glass can be supplied in different sizes and thicknesses. Most common sizes are manufactured by Iranian Glass Factories are as below:

(All Figures are in Meter)

2.14 x 3.21

2.14 x 3.05

2.25 x 3.21

2.44 x 3.21

1.22 x 1.83

1.22 x 2.44

1.83 x 2.44

2.25 x 1.605

2.14 x 3.66

2.25 x 3.66

2.44 x 3.66

3.21 x 6

Most Common Thicknesses from Iranian Float Glass factories: 

(All Figures are in Millimeter)









At Zista Group, with basis of our commodity trading and also financial capabilities, we have been able to reserve quantities of Float Glass reserved based on allocations as factories are usually booked for months to come. Therefore, the allocations provide a better business chance as international clients usually cannot adapt to factory payment, procedures and commercials terms which are too domestic. So providing reasonable and safe commercial terms in addition to logistics solution has been the key to supply of Float Glass from Iran.

Respectively, in Zista Group, we have been able to export Iranian Float Glass to several international markets and as Iranian production capacity is rising in the coming years, so will the export possibilities.

Packaging of Float Glass is inside safe wooden boxes with special technic to minimize broken pieces as demonstrated in the photo for containerized delivery worldwide.

Float Glass Applications

The main Applications of Float Glass are:

  • Automobile Glass 
  • Windows and Doors
  • Mirrors
  • Furniture
  • Insulated Glass
  • Frosted Glass
  • Laminated Glass
  • Tempered Glass