SABIC, a global leader in the chemical industry, released the results of a recent lifecycle assessment of passenger car side doors using hybrid material solutions including laminates made with its continuous fiber-reinforced thermoplastic composite (CFRTC), the UDMAX GPP 45-70 tape. The material system aims to help improve compliance with stringent energy and emissions regulations.

The externally certified, cradle-to-grave life cycle assessment (LCA) found that doors made with the glass fiber polypropylene-reinforced composites outperformed metal car doors in two key environmental categories: global warming potential and cumulative energy demand.

In addition to weighing significantly less than steel, aluminum and magnesium, the CFRTC parts deliver exceptional strength, corrosion resistance and the ability to be produced in high volumes using injection molding.

The lifecycle assessment, performed in compliance with ISO 14040/44, compared a side door of a passenger car (a typical sedan) made with thermoplastic matrix composites comprising UDMAX GPP 45-70 tape combined with an injection-molded grade of glass-filled thermoplastic resin, to identical doors made of steel, aluminum and magnesium.

Based on the design specifications, the UDMAX tapes were converted into a laminate and then overmolded onto both sides of a substrate using SABIC’s STAMAX glass reinforced polypropylene product, creating a hybrid material system. Parameters for vehicle operation were based on three powertrains: internal combustion (no adaptation); plug-in hybrid and battery-electric, operating over a lifetime of 200,000 km using the New European Driving Cycle.

• The results for the internal combustion powertrain showed that the thermoplastic composite doors achieved lower global warming potential than any of the three metal doors: 26% lower than steel, 21% lower than aluminum and 37% lower than magnesium. These numbers were slightly different for the hybrid and electric powertrains.

• For cumulative energy demand, the thermoplastic composite doors also achieved lower numbers than the metal doors: 10% less than steel, 13% less than aluminum and 26% less than magnesium for the internal combustion powertrain. Again, the results were slightly different for the hybrid and electric powertrains.

Key reasons for these results begin with the lighter weight of the UDMAX GPP based laminate as part of the application:

• 40% lighter vs. steel

• 15% lighter vs. aluminum

• 7% lighter vs. magnesium

Many countries, including China, Japan and several across the European Union, have announced they will tighten vehicle emissions regulations in the near future. These impending changes add urgency to the need for advanced new material solutions that can reduce part weight without sacrificing performance.

—Scott Fallon, global automotive leader, SABIC

In the European Union, 95% of all passenger cars must achieve 95 g/km of carbon dioxide by 2020 with 100% compliance by 2021. In China and Japan the requirements are 117 g/km of CO₂ and 122 g/km of CO₂, respectively, by 2020.