Polycarbonate Grades And Some History
Polycarbonate sheet is a common material for a variety of glazing applications, impact resistant shields and formed parts. Polycarbonate Sheet and Rod are generally produced from plastic resin produced by two main plastic resin manufacturers:
1) Sabic (Saudi Arabia Basic Industries Corporation) Plastic, producing a wide range of plastic resins including: Lexan® Polycarbonate, Cycolac® ABS, Noryl® – Poly Phenylene Oxide (PPO), Ultem® 1000 and Ultem® 2300 PEI resins.
2) Covestro (Formerly Bayer Plastic) that focus mainly on the Makrolon® Polycarbonate resin and some Polyurethane and Coatings.
The general purpose Polycarbonate resins are about the same as they were when they were first invented. The research on this resin started in 1898, but was first perfected by Bayer in Germany and was patented and registered in 1955. Amazingly, one week after the first invention by Bayer, Daniel Fox at General Electric in New York, independently synthesized a branched polycarbonate resin.
Both companies filed for US Patents in 1955, and agreed that the company lacking priority would be granted a license to the technology. The patent was resolved in Bayer’s favor, and Bayer began commercial production under the trade name Makrolon® in 1958. GE Plastics began production under the Lexan® trade name in 1960.
Today, there are numerous versions of these Polycarbonate resins, produced by a dozen different resin manufacturers; however Lexan® and Makrolon® still lead the field.
In addition to the dozen resin manufacturers, there are also dozens of extruders that can produce the Polycarbonate in sheet or rod. The leaders are Covestro, SABIC and Plazit Polygal. All three have extrusion equipment in the USA, and produce high clarity Polycarbonate Sheet. Some of the leaders in Thick Plate and Rod extrusion are Ensinger Plastics, Polymer Plastics, Westlake Plastics and Gehr Plastics.
The different versions of the Polycarbonate resin cover a wide range of manufacturing machinery, ie: Injection molding, Extrusion, Blow molding, etc. In addition, there are different Polycarbonate grades based on the applications where the material will be used.