Bonding two panes of glass to produce an interlayer creates laminated glass, which has become a catch-all term to cover the various combinations of glass and interlayers. Even when glass breaks, the interlayer holds the broken glass, and it’s this feature that makes laminated glass a popular choice where security is a priority. The most commonly found interlayer is PVB. EVA is also a popular choice.
Where a transparent plastic material, such as PVB and EVA, is used for the interlayer, the bond is reached by applying both pressure and heat in a controlled setting. Plastic interlayers, however, make cutting difficult. Adhesive resin is more flexible and allows for the production of a curved laminate.
As a moisture-absorbing material, PVB can draw in moisture and can turn cloudy because of this. Inadequately storing PVB can cause it to have elevated levels of moisture before use, while effective end sealing of the glazing prevents moisture infiltrating the interlayer; both problems could result in delamination. Delamination is possible also if there is distortion in the fitting of the two panes of glass which introduces stresses in the interlayer. Glass suppliers Bristol can provide more information.
What is laminated glass?
It is important to understand when choosing the glass to be used in a rooflight system, that the combination of interlayer and glass panels that form the complete part is able to achieve the desired performance.
Laminated glass consists of at least two sheets of glass forged together to form a plastic interlayer, which holds the glass together and enables it to remain in the frame should one or both sheets of glass break. Therefore, it is safety glass and can be used where glass is required overhead. For Glass suppliers Bristol, visit a site like Roman Glass.
What does heat strengthening mean?
Laminated glass that has been treated with heat strengthening is considered the most effective option for the installation of rooflights made form glass. It is like to annealed glass, except the glass sheets have been laminated together with a heat strengthening process and offers two times the strength of annealed glass, as well as being heat resistant to thermal stress cracking. It does not suffer from the small risk of Nickel sulphide inclusions which may affect some forms of toughened glass.
Heat strengthened glass is a more expensive option, but it offers a comprehensive specification for overhead use, because it is considered as a safety glass that will be retained in the frame if it is damaged and is not vulnerable to heat stress thermal cracking. A rooflight with heat strengthened laminated panels is classified as non-brittle.