The CNUD name is associated with annealing lehrs for the hollow flat and float glass industry. The first lehrs were built in 1957 to respond to the demands of the hollow glass industry. A few years later the company introduced the concept of a steel construction for flat and float glass production. This innovation offers the flat and float glass industry better control over the process and a spectacular increase of the yield in comparison to brick annealing lehrs. Annealing is a critical phase of the float glass production cycle. If not properly annealed, the glass will develop stresses due to uncontrolled cooling. This will lead to glass breakage and a reduced yield. The CNUD annealing lehrs are known worldwide for their high performance and for their exibility in operation.