Placa de vidro laminado á prova de som e filme que é destinado a atuar como uma camada intermediária em uma placa de vidro laminado

摘要

In laminated glazing used for acoustic insulation and comprising two or more rigid transparent sheets and one or more insulating and/or strengthening plastic films, the novelty is that the plastic film is associated with a film having ordinary acoustic quality, i.e. (a) when this film is 2 mm. thick and is assembled with two 4 mm. thick glass sheets to form a laminated slab of 9 cm. length and 3 cm. width and subjected to impact, the primary mode resonance frequency (fc) differs by more than 35% from that of a 4 mm. thick monolithic glass slab of the same length and width; or (b) when the film is max. 1 mm. thick and is assembled with two 2.1 mm. thick glass sheets to form a laminated plate, the measured acoustic attenuation index deviates, for frequencies greater than 800 Hz, by more than 6 dB from a reference index increasing from 9 dB per octave up to 2000Hz and by more than 3 dB per octave at higher frequencies. Also claimed is a film for insertion in laminated glazing to provide insulating and/or strengthening properties, the film being associated with a film having ordinary acoustic quality as described above. Pref. the film having ordinary acoustic quality is a standard polyvinylbutyral film and is separated from the insulating and/or strengthening plastic film by an impervious thin film pref. based on polyethylene terephthalate.