Laminated glass VSG introduction

Laminated glass is used for architecture, glazing, automobile safety, photovoltaic, UV protection, and artistic expression.The most common use of laminated glass is automobile windshields and skylight glazing. In geographical areas requiring hurricane-resistant construction, laminated glass is often used in exterior storefronts, curtain walls, and windows. Laminated glass is also used to increase the sound insulation rating of a window, because it significantly improves sound attenuation compared to monolithic glass panes of the same thickness.

The interlayer is typically of polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), ionoplast polymers, cast in place (CIP) liquid resin, or thermoplastic polyurethane (TPU). An additional property of laminated glass for windows is that an adequate TPU, PVB or EVA interlayer can block nearly all ultraviolet radiation. A thermoset EVA, for example, can block up to 99.9% of all UV rays.The thermoset EVA offers a complete bonding (cross-linking) with the material whether it is glass, polycarbonate (PC), or other types of products. For sound insulation, if using EVA or TPU, no additional acoustic material is required; if using PVB, a special acoustic PVB compound is used.

Benefits

The main benefits of laminated glass are: increased safety/security, reduced emissions, reduced noise pollution, and protection during natural disasters. Laminated glass increases safety for people during vehicle accidents since their windshield will stay intact, preventing glass fragments from injuring passengers. For security, laminated glass is difficult to break, which prevents intruders. Laminated glass can also reduce heating from the sun, allow building interiors to stay cool and reducing energy consumption. Depending on its thickness, laminated glass can reduce noise pollution coming from the exterior. In natural disasters such as hurricanes or earthquakes, laminated glass will remain intact and reduce potential injuries and deaths.

Cutting

Plastic interlayers in laminated glass make its cutting difficult. There is an unsafe practice of cutting both sides separately, pouring a flammable liquid such as denatured alcohol into the crack, and igniting it to melt the interlayer to separate the pieces.[citation needed] The following safer methods were recommended by the UK Government's Health and Safety Executive in 2005:

Special purpose laminated cutting tables

Vertically inclined saw frames

A blowlamp or hot air blower.

High pressure abrasive waterjet.

Cutting laminated glass requires a different scoring procedure since the glass has resistance to fracture. Laminated glass can be broken through breaks, which depends on the distance between the edge of the glass and its score. The most common breaks for laminated glass are pressure break, tweak break, table break, tap break, and pliers break. Pressure breaks, intended for scores that are more than 12 inches from the edge, flips the glass over on a table surface with the score facing downwards. Pressure would be applied on either sides of the score until the glass panel breaks. Tweak break, meant for scores between 4 and 6 inches from the edge, involves using one's fingertips to propagate the break along the score line. Table break, recommended for glasses with at least 12 to 18 inches from the edge, uses the table edge to break the score. For scores close to the edge, tap break is recommended at the expense of a scalloping effect on the glass edge. For this type of break, drop jaw pliers or glass pliers are used to break the glass along the score. For scores less than 1/2 to 1 inches from the edge, pliers break would use pliers to place a downwards pressure on the glass, breaking the score through an angle.

After cutting the laminated glass panels, there are different ways to separate the interlayer. The most common methods are melting it and cutting it. Before, glaziers often used denatured alcohol to melt the polyvinyl butyral (PVB) layer, however, this method proved to be dangerous as alcohol is flammable. A safer alternative is to melt the PVB lamination layer with a heat gun. Once the interlayer is melted, the separation is cut using a single-edged razor blade or a tape measure blade. With the blade, one would stroke the score and cut the PVB until the glass is separated from the interlayer completely.