Applied in architecture, construction, and automotive industries amongst others, laminated glass is a durable and secure product. It is made up of two or more pieces of glass sandwiched between a plastic interlayer normally made of ethylene-vinyl acetate (EVA), polyvinyl butyral (PVB), or some other material. From raw material purchasing to use of advanced bonding and quality control procedures, production of laminated glass includes some significant steps.
- Raw material selection
Production of laminated glass starts with the treatment of the appropriate raw material choice. Two parts of glass and one material to be used as an interlayer are the two basic components. There are the thickness, strength, and clarity requirements of the glass sheets. Although specialty glasses like tempered glass or low-emissivity glass do exist which can be used in some applications as well, float glass is normally used because of the smooth finish and homogeneity. The most commonly used interlayer material is PVB, chosen for its adhesion to glass. Safety characteristics of laminated glass such as resistance to impact, and other features such as filtering of UV rays or sound insulation.
- Cutting and neatening
Cutting is performed on the interlayers and sheets of glass that have been chosen to the requisite size. This process needs precision to ensure that the glass, whether being employed for constructing windows, automobile windshields, or any other application, is of the desired quality for the purpose. After the cutting, both the interlayer and the glass are cleaned thoroughly to remove any dirt, oils, or grime. This has to be carried out to provide the interlayer with good sticking to the glass. Impurities may cause the bond to weaken, and thus the strength and security of the laminated glass as a whole become less.
- Layers and pre-pressing
The interlayer is then placed between the two pieces of glass in the second step. Various layers of interlayer material and glass can be used to form the laminated glass, depending on what the final product will be. Laminated glass is guaranteed to have the strength and safety components that it requires to fulfil the purpose for which it is being used because of piling this layer. To force out any air pockets or gaps between the layers, interlayer and glass are subsequently pre-pressed. To create laminated glass as transparent as possible and clear of defects that would compromise the integrity of its structure or disfigure its appearance, the aim is to have an equal bond between interlayer and the fragments of glass.
- Heat and Pressure Bonding in the Laminating Process
Heat and pressure are employed to actually bond the material, typically in a specialized autoclave. The glass and interlayer sandwich is then heat-formed (typically between 140°C and 160°C) and pressurized (to 14 bar or higher) in an autoclave, a pressure oven. In this process, it is ensured that the interlayer is fully bonded to the glass, making laminated glass extremely resistant to impact and durable. Any small gaps between the glass sheets are sealed in by the interlayer, which is softened and molten by virtue of the heat and pressure treatment.
- Technology Improvements in Manufacturing
Technological development in laminated glass production has enhanced the strength and performance of the end product. Developments in form of better autoclave processes, improved interlayer materials, and the inclusion of sophisticated coatings (for instance, for UV protection or sound insulation) have rendered laminated glass more resilient, secure, and energy-efficient. Technological advancements also facilitate the production of thinner-profile, lighter, and more superior optical performance laminated glass.
The production cycle of laminated glass is characterized by a careful sequence of actions, from selection and cutting to heat and pressure bonding in the autoclave. Every stage is intended for the final result to be as strong, sturdy, and secure as possible and suitable for practical application in anything from cars and buildings to bridges and airplanes. With ongoing improvement in technology, laminated glass will be used even more ubiquitously and efficiently, contributing greater safety, performance, and design flexibility for industries globally.
Sources:
Company: FG Glass India, BetterGlass.com, Noval glass
