Curved glass is the new black.
We already know why glass walls are popular: transparent, sustainable, acoustically superiority, light-friendly. As the technology in glass manufacturing advances, it’s becoming easier and easier to manipulate glass – or most other materials for that matter – into the shapes we want. A soothing alternative to sharp corners, glass walls provide the illusion of expanded space. They also allude to a sense of safety. When I visualize curved glass, I feel peace, ease, an aura of luxury.
When did humans first start using curved glass?
The earliest examples can be traced back to the Roman Empire, where they used it for decorative purposes such as in the making of mosaic windows. However, the production of curved glass was a difficult and expensive process. Today, it is still considered a luxury.
The resulting curved glass was used in many architectural designs, including the iconic Crystal Palace in London, built for the Great Exhibition of 1851.
Throughout the 20th century, the production of curved glass continued to evolve, with new technologies and materials making it more accessible and affordable. Today, curved glass is used in a wide range of applications, from skyscraper windows to automobile windshields to smartphone screens.
Overall, the history of curved glass is one of innovation and evolution, as designers and manufacturers continue to push the boundaries of what's possible with this versatile material.
How is Glass Made?
There is more than one method to curve glass.
- Hot Bending
In the late 19th century, a new technique was developed for producing curved glass, called "bending." Hot bending is the most popular method for creating curved glass. As the name indicates, the straight or pre-curved glass is slid into a machine that has been heated from anywhere between 580 – 600°C. It slides over a set of rollers that have been bent into the angle of the desired shape. Gravity works its charm and pulls the glass against the shape of the wheels/rollers. In 10 seconds, the glass comes out of the other end, and voila: it’s curved. Adjust the rollers to fit the glass into the desired radius.
- Cold Bending
A more cost-effective alternative to hot bending, cold bending is more dependent on physical force. Unlike hot bending, cold bending does not require the glass to be significantly above room temperature. We must keep in mind that the glass must be tempered before applying this method.
Similar to bending, this technique involves heating a flat piece of glass in a kiln until it reaches its softening point, and then letting it slump into a mold through gravity. This method has more limits in terms of smaller radii.
Lamination is a process where two or more layers of glass are bonded with an adhesive material. This technique can be used to create curved glass by shaping the glass layers to the desired curvature before bonding them. This method is often used for creating curved glass that needs to be shatter-resistant or bulletproof.
Casting involves pouring molten glass into a mold with the desired shape, then cooling it until it hardens. This technique is often used for creating artistic pieces of curved glass, such as sculptures or decorative objects.
- Vacuum Forming
Vacuum forming is a method where a flat piece of glass is heated until it becomes pliable, then placed over a mold and vacuum-sealed around the edges. The vacuum causes the glass to conform to the shape of the mold, resulting in a curved piece of glass. This technique is commonly used in creating automobile windshields and other applications where a large, curved piece of glass is needed.
Each of these methods has its own strengths and weaknesses, and the choice of which one to use will depend on the specific application and requirements of the project.
Does Curve glass have higher value?
Let us rewind a bit.
We have discussed the technology and physical labor that goes into the creation of curved glass. The mental labor must not go unappreciated. From providing the correct dimensions of job site to ordering the glass, it involves all the technical departments to employ thorough communication.
Curved glass goes through a far lengthier process than straight glass during the pre-production stages. The primary architectural drawings are sent to the drafting department to create a document called SDA (Shop Drawing for Approval).
The SDA is sent back to the architect. After client review and on-site measurements, the pre-production team analyzes dimensions and specifications. This process can take up to a day. There is absolutely no room for error. It is then sent to the drafting department. A drafter’s special attention to precision must not go unnoted.
Its intricate detailing can take anywhere from 1 to 6 hours, depending on the experience of the drafter. It is then sent back to pre-production for a final validation, then to the glass department which calculates the glass size and prepares the pdf to be sent to the purchasing department.
Curved glass is a dedication, with a myriad of factors and professionals involved in its creation. The result is a timeless element of sophistication and elegance to any space.