What is Float Glass? All You Need To Know
Float glass is a highly polished, optically pristine type of glass that finds extensive use in various window applications, as well as serving as a foundational material for an assortment of other glass types, such as heat-absorbing tinted glass and laminated glass.
The manufacturing process of float glass involves pouring liquefied glass from a furnace into a chamber that contains a molten tin bed, known as the Pilkington Process. The atmosphere within the chamber is meticulously monitored to ensure optimal conditions, allowing the glass to float atop the tin and conform to the shape of the container. The glass then expands to a width of 90 to 140 inches, with its thickness being predetermined at the time of production.
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What Are Float Glass Used For?
Glass has become an indispensable element in contemporary architecture and design, adorning everything from towering skyscrapers to chic co-ops, opulent villas, and swanky offices. The reason behind its widespread adoption is not just its sleek and sophisticated aesthetic, but also its remarkable functionality that meets the diverse and ever-evolving demands of modern-day consumers. Glass offers solutions for safety, durability, acoustic insulation, energy efficiency, and much more. And at the heart of all these solutions lies the crown jewel of modern glassmaking: float glass. Not only does it embody a captivating and ethereal beauty, but it also serves as the foundation for all other cutting-edge glass solutions available today.
What Is The Float Glass Process?
Yavuz Industrial Glass is a leading manufacturer that employs the highly-technical Float Glass Process to produce high-quality, flat glass for the construction and automotive industry. Developed in 1959, this advanced process harnesses the power of some of Earth’s most abundant raw materials to create a durable and reliable glass product. The key ingredients in the production of flat glass include silica sand, which constitutes 60% of the glass; limestone, which enhances glass strength; soda ash, which enables the glass to withstand a range of temperatures without melting; dolomite, which enhances glass’ resistance to melting; and glass cullet, commonly referred to as “broken glass,” which accelerates the melting of glass during the float glass process.
In the float glass process, a continuous stream of molten glass heated to over 1000 degrees Celsius is poured from a furnace onto a large, shallow bath of molten tin. The glass floats on the surface of the tin and cools, gradually forming a flat surface. The thickness of the glass is determined by the speed at which it is drawn using a controlling glass ribbon. The glass produced in this process is perfectly flat and parallel.
Rollers are then used to stretch or pull the glass to achieve a thinner finished product. At Yavuz Industrial Glass, we take pride in producing high-quality glass products that meet the most stringent quality standards, making us the go-to source for all your glass needs.
Types of Glass From the Float Process
The float process is widely used to produce two types of glass: clear glass and tinted glass. Clear glass, as the name suggests, is colorless and transparent, and it constitutes the majority of flat glass produced using the float process. Depending on its thickness, clear glass can transmit about 75 to 92 percent of visible light.
In contrast, tinted glass (also known as heat absorbing glass) is created by adding coloring agents such as bronze, gray, green, and blue to the batch mix. As the thickness of the glass increases, the density of the color deepens, resulting in less visible light transmission. The light transmittance of tinted glass varies from 14 to 83 percent, depending on the thickness and color of the glass.
It is important to note that tinted glass not only reduces visible light transmission, but it also helps to block infrared radiation, reducing the amount of heat that passes through the glass. As a result, tinted glass is often used in applications where heat control is a major concern, such as in buildings located in areas with hot climates. Additionally, tinted glass can be used to enhance privacy by reducing the visibility of the interior of a building or vehicle. Overall, the float process offers a versatile range of glass products that can meet various functional and aesthetic needs.
Properties of Float Glass
As previously stated, one of the main advantages of float glass is its completely uniform surface. Unlike earlier manufacturing methods, glass can be produced using the float process, resulting in a clear and undistorted view.
Additional characteristics of float glass include:
Resistant to scratches
Weight: approximately 2.5 kilograms per square meter and millimeter of glass thickness
Planar surfaces: Both sides of the glass surface are completely flat and parallel to each other.
Color: Float glass typically has a slightly greenish hue, which is particularly noticeable at the edges. Lighter glass uses special raw materials low in iron oxide (see also “Float glass vs. white glass” below).
High light transmission: Conventional float glass (single glass, 3-10 millimeter thickness) has a light transmission of around 85-90%, with even higher values for white glass.
Temperature change resistance: Approximately 40 Kelvin (for unprocessed glass without safety treatment), which means float glass can withstand rapid temperature changes up to 40 Kelvin.
Due to these properties and its relatively low-cost production, float glass is used in a wide range of applications today. About 95% of flat glass is float glass and it is used for:
Windows, Mirrors, Car windows, Facade glazing, Greenhouses, Glass furniture
Float Glass Manufacturing
Let’s take a closer look at the production process of flat glass.
- Raw materials In the first step, the raw materials needed for glass production are mixed and melted. The following raw materials are required for glass production:
- Quartz sand
- Soda (sodium carbonate)
- Dolomite
- Lime (calcium carbonate)
In most cases, 10-15% of cleaned and recycled glass fragments are added. The so-called batch is made up of these “ingredients” in the melting furnace.
- Float process In the next step, the mixture is heated to around 1100 °C. Due to their different densities (the glass mixture is about two-thirds lighter than tin), the two substances do not mix. The glass floats on top and spreads evenly in all directions. The characteristic smooth surface is created by the surface tension between the tin and liquid glass.
Meanwhile, the production of flat glass is a continuous process – once started, the plant operates around the clock without interruption. The glass mixture is permanently replenished from one side, while the cooled glass ribbon is drawn and cut from the other side.
- Cooling and cutting The glass is then slowly cooled without being subjected to stress. As soon as it reaches a temperature of “only” 600 °C, the glass ribbon can be lifted out of the tin bath. The glass is further cooled in a cooling furnace. Then it is checked for quality, washed, and cut to the desired size.
What are the uses for flat glass?
Flat or float glass possesses a variety of qualities that have already been discussed, making it a highly versatile material in the production of a wide range of consumer goods. Its superior quality provides manufacturers with structural flexibility, as it can be molded and bent through different processes and subjected to high temperatures.
Moreover, the glass boasts high resistance, making it suitable for application in a broad spectrum of areas, including:
Modern construction and architecture, where it can be used in insulating units to achieve exceptional energy benefits.
The automotive industry, where it can be found in the production of windshields, mirrors, windows, sunroofs, and more.
The manufacture of cabinet doors, table coverings, furniture, and decorative elements.
Optical industry, photovoltaic and electronic sectors, and others.
Thanks to its properties and characteristics, coupled with technological advancements, flat glass can be made into a range of products or compositions, such as:
Annealed glass
Tempered glass
Laminated glass
Armored glass
Safety glass
Thermo-acoustic glass
Reflective glass
Decorative glass
Silk-screened glass
Sandblasted glass
Thermo-toughened glass
Vitrified glass
Lacquered glass
Satin glass
Printed glass
Reinforced glass
These various forms of flat glass cater to a broad range of applications, making it a highly sought-after material in many industries.
Have questions about a flat glass project for your home or business? Contact us at +90 530 768 3116 for pricing, expert workmanship and emergencies.
