Polycarbonate (PC)

About Polycarbonate Plastic

Polycarbonate (PC) is a high-performance engineering thermoplastic known for its virtually unmatched combination of optical clarity, impact resistance, and heat tolerance. Its amorphous structure gives it excellent dimensional stability and transparency (up to 90% light transmission), while its high notched Izod impact strength makes it one of the toughest transparent materials available — up to 250 times stronger than glass and 30 times stronger than acrylic.

PC's heat deflection temperature (typically 130–140°C) makes it suitable for applications that require both structural integrity and optical performance at elevated temperatures. It is inherently self-extinguishing and available in UL94 V-0 and V-2 flame retardant grades, making it widely used in electrical and electronic enclosures. PC is also an FDA-compliant material in food-contact grades.

Polycarbonate is hygroscopic and must be thoroughly dried before processing — typically at 120°C for 4–6 hours. Proper drying is critical: moisture levels above 0.02% cause hydrolytic degradation during processing, resulting in loss of molecular weight and mechanical properties. Melt temperatures for injection molding typically range from 280–320°C, with mold temperatures of 80–120°C recommended for optimal surface quality and low internal stress.

Polycarbonate for Injection Molding

PC is one of the most widely injection molded engineering plastics. Its high melt viscosity requires machines with sufficient injection pressure (typically 1,000–2,000 bar), and the use of general-purpose or hot-runner tooling with properly sized gates and runners. Due to its amorphous nature, PC exhibits very low and consistent shrinkage (0.5–0.7%), which is a major advantage for tight-tolerance parts.