New manufacturing technologies and new studies in industrial applications developed some innovative methods for metal sheet cutting. These recent techniques are known as hot working processes, they convert renowned power sources (such as laser) into new applications.
We outline three important hot working process for metal cutting:
- Oxy-fuel: metal sheet is shaped by gases through a torch (similar to a welding torch). The reaction between oxygen and acetylene heats the material (reaching 980°C/1796°F) so that it melts instantly. The oxy-fuel cutting is ideal for sheet up to 5,9in (15cm) thick.
- Plasma cutting: this technology uses a gas jet, generally a mixture of hydrogen and nitrogen. During the process the high temperature ionization ensures local melting on the cutting line. It’s suitable for every kind of metal and it doesn’t overheat the sheet. Plasma cutting guarantees very fast and accurate results even with metal sheet up to 0,78in (20mm) thick. The whole process is guided by CAD software.
- Laser cutting: the development and the spread of these machine tools started in the 80s and it is constantly evolving. New technological projects are testing new tools able to cut materials such as ceramic, rubber, plastic and composites.
Laser cutting machine uses an intense beam of monochromatic light, which reaches extremely high temperatures and so it allows metal sheet cutting. Engraving will be minimal as well as the metal waste. Similarly to plasma cutter, this machine is automatically controlled by CNC using CAD software. It fits for cutting sheets up to 0,78in (20mm) thick and it can’t be used with every material.
In the last few years, new kinds of laser have been tested with new power sources such as fiber, liquid-crystal and CO₂.
Pay special attention to the fiber laser. Its working is based on optical fibers as amplifiers which are fueled by injection laser diodes. It is the ideal technique for engraving, it requires low maintenance and it has an extended lifetime (the average life is 25.000 hours).