A new lifecycle assessment of passenger car side doors using hybrid material solutions was presented by petrochemical manufacturer SABIC at JEC World 2018 during March 6-8 in Paris. Materials used to construct the doors include laminates made with the company’s continuous fiber-reinforced thermoplastic composite (CFRTC), the UDMAX™ GPP 45-70 tape, a material system engineered to improve compliance with stringent energy and emissions regulations.

The externally certified, cradle-to-grave life cycle assessment found that doors made with the glass fiber Source: SABICpolypropylene-reinforced composites outperformed metal car doors in two key environmental categories: global warming potential and cumulative energy demand. The CFRTC parts weigh significantly less than steel, aluminum and magnesium, and deliver exceptional strength, corrosion resistance and the ability to be produced in high volumes using injection molding.

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

The analysis was performed in compliance with ISO 14040/44 and compared a side door of a passenger car made with thermoplastic matrix composites composed of 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. The UDMAX tapes were converted into a laminate and then over-molded 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 electric – operating over a lifetime of 200,000 km using the New European Driving Cycle.

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 percent lower than steel, 21 percent lower than aluminum and 37 percent 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 percent less than steel, 13 percent less than aluminum and 26 percent less than magnesium for the internal combustion powertrain. Again, the results were slightly different for the hybrid and electric powertrains.

These observations are largely attributed to use of the lighter weight of the UDMAX GPP-based laminate, which is 40 percent lighter than steel, 15 percent lighter than aluminum and 7 percent lighter than magnesium.