07 Aug Laser welding for long-term waste storage containers
As the use of electric vehicles continues to grow, so does the need for the safe, long-term storage of battery materials and chemical industrial waste. Certain types of waste require disposal in so-called Category IV landfills, where containers must meet particularly stringent requirements. They must ensure environmental protection, safe handling and long-term stability.
Highly chemically resistant glass containers could contribute to the safe long-term storage of hazardous waste. As part of the LasGlaReLa project, researchers at the Laser Zentrum Hannover (LZH) have developed a laser welding process that, according to the institute, produces a continuous weld seam without microgaps or voids.
5 mm glass fully welded
According to the institute, the process is suitable for the automated production of securely sealed containers. Owing to its chemical resistance, glass is considered a suitable material for the long-term storage of hazardous substances. Until now, such containers have been manufactured primarily using thermal gas-based processes. However, these methods introduce significant heat input and make automated production more difficult.
Despite the heat input during laser welding, the glass retains its mechanical strength. Photo: LZH
In the project, the researchers used a CO₂ laser with a wavelength of 10.6 µm. Despite its shallow optical penetration depth, they succeeded in heating both joining partners simultaneously and fully welding 5 mm thick flat glass sheets. The process produced a continuous weld seam without microgaps or voids.
According to LZH, the samples retained their mechanical strength even after two weeks of storage. In addition, the glass lid automatically settles into the correct position under gravity during the welding process, eliminating the need for clamping or handling systems.
Ongoing work focuses on further optimising the edge geometry of the glass components to reduce friction as well as material bulging in the weld area, explain the researchers.
About LasGlaReLa
The project ‚Novel Manufacturing Technology for the Production of Laser-Welded Hollow Glass Bodies for Waste Storage’ (LasGlaReLa) was funded by the German Federal Ministry for Economic Affairs and Energy under grant number VN-KK5111715. Project partners were TU Bergakademie Freiberg and Glasbiegerei Pfaltz.
Source and image: www.lzh.de