What Type of Plastic Is Safety Glass Made Of?

Safety Glass Manufacturing

• Laminated safety glass is made by pouring liquid polyvinyl butyral, or PVB, between two or more sheets of glass. This is cured to a hard state and bonds the glass sheets together. Although the outer glass will break if struck by something hard such as a hammer, the inner layer of plastic will resist breakage. More resistance can be added by using several thin glass and plastic layers, as is done with bulletproof glass.

About Polyvinyl Butyral

• PVB resin was invented in the 1930s and is primarily used to make safety glass. When used in this manner, the polyvinyl butyral resin is combined with a plasticizer. When heat and pressure are added, the result is a thin sheet with outstanding strength characteristics. PVB is transparent and formable, like glass, and is a nontoxic, noncorrosive plastic product. It is impact- and age-resistant and contains no inorganic or organic acids. Although not dissolvable in water, it is soluble in organic solvents such as ester and alcohol.

Benefits

• Polyvinyl butyral is able to absorb up to 99 percent of the sun’s UV rays, which aids in preventing damage to window coverings and furniture while still allowing light to come through your window. It also reduces noise, although its sound-reduction properties vary depending on the thickness of the plastic. PVB may be colored to provide different lighting effects and may be tinted to deflect the sun’s rays and save on cooling costs.

Other Uses

• Aside from its use as safety glass in residential, commercial and automotive applications, PVB is also used as a surface coating for glued wood board products and an undercoating for insulating materials. It is mixed with other resins and used to coat metal products as well. Because it adheres well to metals, PVB is a good priming coat for metals such as steel, iron, copper and aluminum. It provides a waterproof coating for tents, coats and fabric bags and is also used on metal foil packaging for medicines, foods and other products. When mixed with phenolic resin, PVB is practical as an adhesive for metals. It is also used as a glass adhesive and on pressure-sensitive adhesive tapes such as glass paper and polyethylene tape because of its elasticity and excellent adhesive properties. PVB is also a rubber and plasticizing agent that is used to adhere fabrics by heating.