Excellent properties of polycarbonate (PC) including high durability, light transmission, simple cutting, and shaping promoted its use in protective gear, medical devices, automotive components, and digital disks. Recycled PC is available in various quality grades and can be used for closed-loop recycling.
Virgin and recycled PC are widely used in various non-food industries requiring light transmittance and good impact strength. After adjustment of the application-specific material properties, the recycled PC can be used for the manufacture of the same products as the virgin material. In order to meet the application-specific requirements, the recycled PC is commonly mixed with the virgin PC and/or modified using suitable additives including UV and thermal stabilizers, flame retardants, etc.
Typical products made of PC are windows and dashboards, traffic lights and safety signs, electrical and telecommunication equipment, building materials such as skylights and noise barriers can be made from PC regrind and pellets. Currently, components made from recycled PC are used in the exterior and interior of motor vehicles, in machine components, architectural models, luggage, components for furniture, and shop fittings. Further use of the recycled PC resins is 3D printing.
Although in some regions PC is approved for use in food-grade applications, there is a concern regarding the health effect of bisphenol A, which is a component in the manufacture of PC.
Polycarbonates (PC) are a group of durable thermoplastic polymers with a density in the range between 1.20 to 1.22 g/cm³. Both virgin and recycled PC are rigid and show high chemical and moisture resistance, as well as high tensile and impact strength. Furthermore, PC possesses good temperature and impact resistance and excellent optical properties, since some grades of PC are transparent. This clearly distinguishes PC from other thermoplastics. Specially processed virgin PC is completely amorphous and therefore highly transparent to visible light. Depending on the collection and separation processes, this transparency can also be maintained in the recycling process. However, due to impurities in the accumulated materials, PC recyclates are usually available in dark grayish colors.
Further valuable properties of PC are the high continuous service temperature of ⩾ 125 °C and good insulation properties against electrical voltage. On the other hand, standard PC has low UV and scratch resistance and requires the use of suitable UV stabilizers and/or integration of a protecting coating. Both virgin and recycled PC is commonly used as a blend with other thermoplastics, like acrylonitrile butadiene styrene (PC/ABS), polybutylene terephthalate (PC/PBT), or polyamide (PC/PA).
The majority of PC waste materials for recycling comes from post-industrial sources, as it is possible to ensure a relatively well-sorted and uncontaminated input stream. Exemplary materials are from medical applications, water dispensers, chocolate bowls, roof lamps, machine guards, bulletproof windows, bank guards and bus shelter windows, roofing membranes, sunglasses and other lenses, dashboards, interior trim, electronic component housings, mobile phones, battery boxes or data storage.
PC from the post-consumer sector are bottles, CDs, and DVDs, as well as vehicle lighting. PC recyclates are usually available as regrinds and granules for further processing.