Details
Material hierarchy: Polymer - Engineering Thermoplastic
Polycarbonate is known for being one of the toughest thermoplastic materials available. It has excellent clarity and can be colored to fit your needs. It is ideal in high continuous use temperatures, up to 250 degrees F, but is limited when exposed to high heat and high humidity for long periods of time. P/C has excellent outdoor weathering properties. P/C is easily extrudable and has good dimensional stability. You will find it in applications where you want to replace glass with an indestructible material such as windows, shields, and even eye glasses. P/C lends itself to many secondary processes like welding, solvent bonding, hot stamping, printing, and more. It can be machined as well as reshaped using heat. Spiratex has a lot of experience extruding tubing and unique profiles from Polycarbonate.
Polycarbonate (PC) is noted for its generally excellent mechanical properties, which include high toughness and good creep resistance. It is one of the best thermoplastics for heat resistance—it can be used to temperatures around 125°C (250°F). In addition, it is transparent and fire resistant. Applications include molded machinery parts, housings for business machines, pump impellers, safety helmets, and compact disks (e.g., audio, video, and computer). It is also widely used in glazing (window and windshield) applications.
Polycarbonates are among the strongest, toughest, and most rigid thermoplastics. In addition, they have a ductility normally associated with the softer, lower-modulus thermoplastics.
These properties, together with excellent electrical insulating characteristics, are maintained over a wide range of temperatures (−60 to 270°F) and loading rates. Although there may be a loss of toughness with heat aging, the material still remains stronger than many thermoplastics.
Polycarbonates are transparent materials and resistant to a variety of chemicals, but they are attacked by a number of organic solvents including carbon tetrachloride solvents.
The creep resistance of these materials is among the best for thermoplastics. With polycarbonates, as with other thermoplastics, creep at a given stress level increases with increasing temperature; yet even at temperatures as high as 250°F, their creep resistance is good.
The characteristic ductility of polycarbonate provides it with very high impact strength. Typical values are about 14 ft-lb/in. of notch on a 1/8-inch thick specimen, although grades are available as high as 18 ft-lb. Unnotched specimens show impact resistance greater than 60 ft-lb. Their fatigue resistance also is very good.
The moisture absorption for polycarbonates is low, with equilibrium reached rapidly. However, the materials are adversely affected by weathering (slight color change and slight embrittlement can occur on exposure to ultraviolet rays).
The trade name for polycarbonate is Lexan. Polycarbonate is an amorphous thermoplastic, with a continuous use temperature range of up to 265°F (129°C). It has a low difficulty to machine. It has excellent impact resistance. It has low moisture absorption. It has excellent transparency. It has superior electrical properties.
Polycarbonate molding compounds are available for extrusion, injection molding, blow molding, and rotational molding. Film and sheeting with excellent optical and electrical properties also are available. Among the specialty grades, glass-reinforced polycarbonates have proved especially popular by virtue of their improved ultimate tensile strength, flexural modulus, tensile modulus, and chemical resistance.
Typical applications include the following: safety shields, lenses, glazing, electrical relay covers, helmets, pump impellers, sight gauges, cams and gears, interior aircraft components, automotive instrument panels, headlights, lenses, bezels, telephone switchgear, snow-mobile components, boat propellers, water bottles, housings for hand-held power tools and small appliances, and optical storage disks.