Bent Glass and its Applications

Posted on : 08-12-2022    Author : Madhabi Banerjee

At some point in time, we all have marvelled at glass architecture that curves such as glass domes in office foyers or churches. Ever wondered how a flat piece of glass can become curved? Would it not break into pieces if it were to change shape? Well, not really! Let us delve more into the world of curved or bent glass.

What is Glass Bending?

Bent glass or curved glass is any glass that is bent or curved into a concave or convex shape. The glass is first steadily reheated till it softens. It is then bent in a controlled manner till it bends into the required shape over a metal mold.  Finally, it is left to cool off till the desired shape is achieved. In glass manufacturing factories, this heating and cooling process is predefined. Glass specialists set the heating and cooling curve parameters based on various factors like size, thickness, type and quality of glass, the type and radius of curvature, the angle at which glass is to be bent, the quality of the mold used, and many more. This makes it all the more vital that the desired design is obtained without losing any characteristics of the glass.

How is Glass Bent?

With technological developments and innovations, the glass industry has improved the process of bending glass over many years. The main technologies involved in the glass bending process are:

• Bending and tempering – In this type of thermal bending, glass is first heated to extremely high temperatures and bent in the bending station, based on the desired radius (usually ¼ of a circle). It is then rapidly cooled to complete the tempering process. Angling the glass can help achieve bidirectional bending, which is lengthwise and crosswise. A bent glass that is tempered offers excellent strength and durability, solar control, and thermal insulation. It also acts as a safety glass and is cheaper to produce.
• Hot bending – Also known as gravity bending, molds are used in this technology. The molds along with the glass are heated to around 600°C, mostly in an electric furnace. The glass is bent in the desired shape and gradually cooled in the annealing process.
• Cold bending – This type of bending is done under normal temperatures where the glass has already been tempered. Therefore, the degree to which the glass is bent is very less. The glass is first put inside a frame and mechanically bent to the required frame shape. The bent glass is then screwed or glued to the laminate frame before it can be installed. Cold bending offers the distinct advantage of higher optical quality. However, it is subject to a lot of bending stresses.
• Lamination bending – In this, the hot and cold bending processes are combined along with lamination. First, the required glasses are bent. Then during the autoclave process, a thick interlayer is placed between the bent glass sheets. Though this method is expensive, flexible shapes can be produced.

Modern glass bending machines, which come in different sizes and models, offer robust structural designs for commercial purposes, based on different needs. These machines help minimize operating costs while providing a balanced and enduring structure.

Applications of Bent Glass

Bent glass when compared to flat glass, offers a more non-conventional and elegant look to any architectural design. Right from doors to building facades, bent glass brings in its uniqueness. Apart from the looks, bent glass also offers high load resistance, increased mechanical strength, and higher durability due to the arching in it. Put to right use, bent glass can greatly reduce the dependence on other building materials. Bent glass also offers thermal insulation, that is, traps the heat within, thus making it the perfect material for climates with vast temperature variations.

With the increasing use of bent glass in architecture nowadays, you will find multiple applications such as walls, revolving doors, domes, skylights, showcases, shower cubicles, balustrades, glass elevators, partition panels, curtain walls, and many more. Keeping in line with the latest interior décor trends, interior designers opt for bent glass tables and bent glass nesting tables to make the room look chic, sophisticated, and visually enticing, and make it the artistic focal point.