In recent years, the use of laminated glass panels consisting of a tempered glass sheet and a hardened glass sheet has had an important diffusion, but the feeling is that this combination is more a formal trick than a real solution to a real problem.

This solution is conceived in note 4 of UNI 7697: 2015 “Safety criteria in glass applications” to guarantee the post-breaking behavior required in Table 1 as an alternative to the use of a “rigid interlayer that remains so at the temperatures of use …” ( ambiguous definition that continues to cause many headaches to sector employees due to the contradictions that characterize it).

In the first instance a hybrid laminate (tempered glass + hardened glass) may appear less expensive than the use of a rigid polymer according to prEN1663: 2013. However, the solution does not enjoy the commutative property between tempered and hardened glass. The tempered glass sheet certainly cannot be replaced, without other considerations, by a hardened glass sheet of the same thickness.

Read the full article