Polycarbonate is a transparent thermoplastic resin with a very high temperature tolerance and impact resistance. Characteristics of polycarbonate include good light transmission, the ability to be machined or thermoformed and good dimensional stability.
Polycarbonate is FDA approved. It is perfect for applications requiring a lightweight, transparent material that is virtually indestructible. Acrylic is known for being a much stronger alternative to glass, but its strength is nothing compared to the bullet-proof hardness of polycarbonate. Also, polycarbonate is one-third the weight of the lightweight acrylic as well.
Both are thermoplastic polymers, which means that they both melt when heated to a certain degree and harden when they cool, a process that can be repeated numerous times. This means that polycarbonate and acrylic plastics are able to be reshaped and recycled, making them more environmentally friendly then thermoset plastics.
Other thermoplastic polymers include; Delrin, which is the trademark name of acetal polyoxymethylene, is a plastic known for its durability and versatility; polystyrene is just as popular in its preformed form of Styrofoam as it is in its final form; PVC, or polyvinyl chloride, has the ability to retain vivid colors, which makes it a popular plastic for home decorating objects such as shower curtains, furniture and interior paneling.
Polycarbonate is a plastic material that can be found in most homes today in the form of CD and DVD discs. Polycarbonate manufacturers also create many other polycarbonate products which are used in applications like shatter-resistant display cases, security barriers, aircraft panels, machine guards, electronic housings and burglar-resistant glazing. One of the major industries that utilize polycarbonate today is the vision care industry.
Because it is transparent and incredibly strong as well as having a high refractive index, polycarbonate is currently the most popular substance for corrective lenses. The high refractive index of a plastic refers to its ability to bend light that goes through it, which is in essence how vision is corrected with prescription lenses. Also, because polycarbonate is naturally highly refractive, corrective lenses made from them are able to be significantly thinner then lenses made from other substances.
Sunglasses, with and without prescription lenses, are also often made with polycarbonate, since it is able to retain fillers that block ultra-violet rays well. Polycarbonate is available in scratch-resistant, flame retardant, anti-static and glass-filled forms. The only down-side to purchasing polycarbonate is that it is more expensive than acrylic or glass, although the fact that it lasts so much longer may outweigh that negative characteristic.