What is Glass Bends?

The uses of glass bends in architecture are endless. Glass bends can be used to create artistic curves or they can be used to create a curved surface that helps with insulation and energy efficiency.

Glass bends are very useful in the field of architecture

Glass bends appear destined to play an important role in future building design, with potential applications in medical technology and industrial design. The reason why glass bends are so useful in this field is that they are inexpensive and easy to install. As you can imagine, this can be difficult because it requires precision and accuracy in order to be completed successfully.

The first step in this process is to heat the glass until it becomes very soft, almost molten with a glass tempering furnace. Once the glass has reached its ideal temperature and consistency, the tempering oven as known as toughening oven will get the glass out from the furnace and lower the temperature of the glass to 300-400 degrees by aid of powerful blowers with cool air, which is a cooling the glass process and called quenching in glass bends production.

Glass bending is a fascinating process that involves heating the glass to a very high temperature until it becomes very soft, almost molten, then putting pressure on it to bend it. The end result is a piece of glass with an elegant shape that can be cut into any number of components for use in interior design or architectural glass for skyscrappers.

Glass Bends

Glass bends involve very high temperatures for a short time

You need to know that glass bends involve very high temperatures for a short time. The temperatures are usually betweeen 600-700 degrees Celsius and are reached in a furnace or kiln. Glass bends are a form of glass art involving the use of high temperatures to create curves in glass. These can be used to decorate windows, mirrors, and even doors. Glass bending is also used in architecture, where it creates artistic curves as well as functional ones.

  • Glass bends require a flat surface so the weight can be distributed over the surface evenly.
  • It needs to be even.

Glass bends involve using heat to deform an object into the shape one wants it to have

Glass bends are used in architecture to create artistic curves in the glass. The glass is heated up, then pressed into a curve that gives the architect more creative freedom. This is because the heat can be controlled by the tempering oven. This means that you will have full control over how much distortion you want from your piece of glass. The distortion can be anywhere from slight to extreme, if desired by the architect but Distortions of Curved Glass and Quality Control must always take in consideration in glass bends.

The bending of glass can be achieved with great precision but requires practice and patience

Glass bends are useful in architecture because they allow for the creation of curved walls or insulated glass, which can be used to create interesting shapes that are not possible with flat glass. The glass bend process involves applying high temperatures for a short time and then cooling quickly. This allows the glass to be shaped into curves without it cracking or breaking.

Is Glass Bending Possible?

Yes, it is possible to bend a glass. Glass bending is done with a glass tempering furnace, which heats the glass to softening temperature before shaping it with a mould and cooling it in room temperature.

Glass bending is a very common process in the glass industry, and it allows you to get your objects and products bent into any shape you want. Today’s glass bending technologies includes 4 different sections:

  1. Glass Bending and Tempering
  2. Hot Bending
  3. Cold bending
  4. Laminated Glass Bending

Let’s dig a little deeper into these 4 different technologies.

1. Glass Bending and Tempering

During the glass bending and tempering process, the glass is typically heated to over 630 °C. The glass is heated before being glass bends to the desired radius in the bending station. Although bending systems are most commonly used to produce cylindrical shapes, small bi-directional bending can be achieved by angling the glass during the process.The glass can be twisted in the direction that it flows, a process known as lengthwise bending. It can also be bent across the glass flow, which is known as crosswise bending.

Because optical quality is always a priority, lengthwise bending produces a higher quality result.

Tempered and bent glass has excellent mechanical strength and resistance to temperature variations. Typically, the maximum bending angle is ¼ of a circle.

Glass Tempering Furnace
Glass Tempering Furnace made in Turkey by CMS Glass Machinery (leading glass machinery manufacturer from Turkey)

Because there is no fasting cooling down process, the strength of hot bending glass is the same as that of float glass. However, the glass can be made into any shape based on the different mould and it is widely used in interior glass tables, glass shelves and glass cabinets.

In contrast to hot bending glass, the tempering furnace completes the heating and cooling process. The rapid heating and cooling processes will create compressive stress on the glass surface.

When the glass is subjected to external force, the surface stress is first reduced to improve bearing capability and glass strength.

Tempered glass bends like flat tempered glass has a high strength and will break into small particles when broken, avoiding potential injury to people.

Tempered glass bends can be classified as follows:

  • Cylindrical glass tempering,
  • Asymmetrical glass tempering,
  • Hyperbolic bending glass,
  • Double curved glass,
  • Multi-curved tempered glass.
Glass Bends Applications

Glass bends production processed in a tempering furnace can be heat strengthened, toughened and heat soaked with the only difference being the shape.

Tempered curved glass is classified into two types:

  • Longitudinal glass bending
  • Lateral glas bending

Lateral glass bending, the glass maximum height is the tempering furnace width, finished glass is used for shower doors, house appliances, and other applications requiring a high level of appearance.

Longitudinal glas bending furnace radius is always larger than lateral bending furnace radius because the contact area between roller squeezer and glass is much larger, and the bending effect is not as good.

2. Hot Bending

The manufacturer uses molds in hot bending to allow the glass to take on the desired shape. The glass and the mold are then heated to 580–600 °C.

Bending can be done solely through gravity. Alternatively, the glass bending process can be aided by a mechanical bending press, which forces the glass into the desired shape. After that, the shape is slowly cooled to remove any residual tension in the glass.

Bending technology enables manufacturers to create a broader range of shapes, such as tighter radiuses and non-cylindrical shapes. The hot bending process adds neither mechanical strength nor the ability to withstand temperature variations to the glass.

Important! All architectural applications that use hot bent glass must be laminated.

Glass Tempering Furnace Energy Consumption
A glass piece inside of the glass tempering oven

3. Cold Bending

Cold bending can be done after the glass has been tempered. As a result, the glass acquires the mechanical properties of safety glass.

Cold bending, as the name implies, is done with the factory’s natural temperature. The glass is first placed in a frame, which mechanically bends the glass into the desired frame shape. The glass is glued by silicone sealant or screwed directly into the frame during the frame installation process. The frame is now ready for installation into the structure.

The bending radius is normally quite large, implying that the glass is only slightly bent. From a mechanical standpoint, the thinner the glass, the easier it is to bend. The shape, on the other hand, can have a twisted design.

Cold bending can be done on an entire insulated glass unit or on individual glass lites. The sealant is subjected to multiple forces when bending a fully insulated unit. Because cold-bent glass hasn’t been around long enough, determining its durability is difficult.

For sealing of the insulated glass units, glass sealing extruders and robots will be required and must be used properly.

Durability of Structural Silicone Sealant in Cold Bent Glazing Design is one of the most important subject and because of that properly usage of structural silicone sealant is critically important in cold glass bending process.

Lamination Glass Bending

Lamination bending is a technique that combines cold and hot bending with lamination. The most common workflow for bent laminated glass is to first bend the glass sandwich – with the desired number of glass sheets in the interlayer and then autoclave it. There are two kind of interlayer is used in glass lamination, those are PVB foil and EVA foil which is placed between two glass to make that two glass stick together and streghten the laminated glass.

You may like to read What is the Difference Between PVB Foil and Eva Foil? article to know more about PVB and EVA films.

It is possible to join two pieces of glass together with an interlayer using the autoclave process. Inside the autoclave, the required processing temperature is around 120–140 °C, and the pressure is around 12 bar.

Before the autoclave process, bending is done with a mechanical fixture, and the original bending radius must be smaller than the target shape.

Because the glass is laminated, it satisfies the safety glass requirements. One advantage of using this process is the ability to create very flexible shapes. Still, this is time-consuming, which raises the cost.

NOTE: The spring effect causes the glass to “straighten” slightly after autoclaving. Furthermore, there may be some relaxation in the glass over its lifetime, causing it to continue to form over time.

What are Glass Bends Aplications?

Tempered glass bends has the following characteristics::

Glass bends allows architects and designers to create aesthetically pleasing curved glazed facades with soft curves that enhance straightness, corners, and edges. Curves can range from simple cylindrical shapes to more complex 3D free form shapes.

The wavy glass bends and curtain wall is fully installed on 111 Murray Street Hotel, the newest project that providing stunning views of the city in all directions the excellent visual effect on glass facade.

Beside glass facade, glass bends can also been applied in below categories:

  • Shower doors or shower cabinets,
  • Glass staircases & hand rails,
  • Glass Storefronts,
  • Hotels and Commercial Buildings,
  • Glass office partitions,
  • Glass skylights.


Glass bends have a wide range of applications beside glass facade and it can also be used in glass balustrades, glass partitions, shower doors, storefronts, glass skylights. As you can imagine the usage is endless!

It is critical to recognize that glass bends and tempered glass, for example, is less expensive to produce than hot bent laminated glass. But, once you understand the technology, the possibilities it provides and the associated costs, designers can already challenge building norms with out-of-this-world designs.

However, because each project is unique, it is always highly recommended that you consult the glass requirements such as arc length of the glass, height of the glass, radius and shapes during your design process to ensure that every piece of curved glass installed on your project is perfect and correct!

We hope that you enjoyed reading our glass bends article and it was useful for you. We would love to hear from you about your glass bends projects if you would like to share with us. You are most welcome comment in below comments section if you have any questions about glass bends in glass processing.