Glass welding creates stronger joints
The new process is superior to joining glass with adhesives because the joint will not deteriorate or wear out. In addition to increasing the strength and stability of a joint, it also decreases the cost.
Welding glass sounds less complicated than it actually is. When cooled, glass is brittle. It also tends to break in random ways because of the molecular structure of glass. In addition, cooled glass has a lower thermal conductivity. Simply applying a laser to the glass will heat the material unevenly, and the glass will crack under the stress. To address this, Trumpf’s system uses a special femtosecond laser that can be programmed to turn on and off variably according to the conditions.
Another challenge of joining solid glass is the fact that glass allows all light wavelengths to pass through. Welding glass requires a very high energy density right at the laser’s focal point, so the process has to be able to concentrate the laser light without allowing too much light energy to escape. The Trumpf laser melts the glass at the laser’s focal point. Melting the glass makes the joint, but the temperature at the focal point also needs to be precisely managed to avoid cracking the cooler surrounding glass. By varying the on-off timing of the laser and managing the cooling process, the laser avoids cracking the glass while the weld is being created.
The process allows manufacturers to replace glued glass joints with welded ones, resulting in a stronger, more economical joint. The company has said that one early application of the technology will be in capping fiber optic cables.
Glassprimer™ glass paint can’t be used to weld glass, or even join two pieces of glass together. But it can be used to create vibrant colors on glass that won’t chip, fade or peel, even after exposure to direct sunlight and high humidity. Glassprimer™ glass paint makes a permanent bond to the glass, so your project will look like new for years to come.