ROMITRON® PPS for E-Mobility
New applications in electric vehicles (EVs) are driving increased demand for polymers with improved thermal and electrical properties. At the same time, greater attention is being paid to other properties such as thermal and electrical conductivity and shielding against electromagnetic interference (EMI). In hybrid electric vehicles (HEVs), the downsizing of the internal combustion engine leads to localized overheating, which must be managed by thermal management systems.
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ROMITRON® PPS offers attractive properties such as outstanding heat resistance (continuous operating temperature of 200 °C), low flammability, and excellent chemical resistance to meet the demanding requirements of electric vehicles. The key factors for the use of ROMITRON® PPS in EVs/HEVs are expected to be as follows:
DEMAND FOR PARTS FOR HIGH-VOLTAGE APPLICATIONS
Plastic parts for high-voltage applications require high flame retardancy and high creep current resistance (CTI), as well as enhanced resistance to thermal cycling and thermal shock testing. Parts such as the cores of inverters and electric motors, enclosures, and capacitor housings must withstand high temperatures and exhibit excellent thermal cycle resistance.
INCREASED DEMAND FOR THERMAL MANAGEMENT SYSTEMS
Compared to vehicles with internal combustion engines, the thermal management systems in HEVs/EVs support, among other things, additional components such as lithium batteries, drive motors (coil operating temperature up to 190 °C), and high-performance electronic control units. The cooling pumps for the batteries and the electric motor operate under the constant influence of water-glycol coolants. The battery cooling systems operate not only while the vehicle is in motion but also during charging cycles, which extends the coolant’s exposure time. Therefore, polymers with higher chemical resistance are required. ROMITRON® PPS is the ideal choice for thermal management in electric vehicles due to its excellent resistance to chemicals and heat.
DEMAND FOR METAL INSERTS
EVs and HEVs feature various injection-molded parts with metal inserts. High-voltage busbars, for example, consist of thick copper bars that are overmolded with PPS due to its good flow properties and excellent electrical insulation.
In addition to ROMITRON® PPS filled with glass fibers and minerals, ROMIRA develops ROMITRON® PPS blends and composites reinforced with special fillers and additives. For example, ROMITRON® EXP3159, filled with 30% carbon fibers, offers high strength and stiffness and can provide injection-molded parts with additional benefits such as EMI shielding. There are various EV components that require EMI protection across different frequencies, such as battery and electronics housings, infotainment housings, and ADAS and LiDAR housings. ROMITRON® EXP3159 can contribute to EMI protection while also offering the highest flammability rating, V-0 (0.8 mm thickness). The use of carbon fiber also facilitates heat dissipation from sensitive areas.
In addition, there is the newly developed ROMITRON® EXP3178 grade, which offers a weight reduction of nearly 35% compared to highly filled standard PPS GF/M65. Thanks to ROMIRA’s many years of experience with composite products and state-of-the-art production facilities, recycled carbon fibers and other lightweight fillers are incorporated into the PPS matrix to achieve significant weight savings.