Introducing Solvay’s Two New Best in Class PPA Solutions
By Brian Baleno, DeeDee Smith, and Nicolas Batailley
Next generation passenger vehicles are deploying e-mobility technologies including batteries, electric motors, power electronics, and 48 volt systems to reduce CO2 emissions and create a more sustainable future. The vehicle architectures using these technologies range from battery electric vehicles to plug-in hybrid electric vehicles, and require either a battery or fuel cell to provide and store the energy and an electric motor plus power electronics for propulsion.
First generation 400 volt electrical systems typically used materials like polyamide 66 or polyphthalamide (PPA) in electronic components such as resolvers, connecting rings, bus bars, and position sensors. Solvay’s Amodel® PPA has been in use in electronic components for nearly three decades but today’s higher performance requirements have raised the bar and led to the development of two new best in class PPA solutions: Amodel® Supreme PPA and Amodel® BIOS PPA.
The development of Amodel® Supreme PPA sprung from the acceleration of the automotive industry beyond 400 volt towards 800 volt electrical systems for next generation electrified vehicles. This shift in higher voltage systems is leading engineers to identify solutions that can provide much better electrical insulation at higher temperatures. Engineers must also account for solutions that offer higher CTI (comparative tracking index), thermal shock resistance over a broad temperature range (-40 °C to 150 °C) and in some cases they need the solution to be flame retardant with a VO rating in order to meet the safety requirements of the electronic component.
Electrified vehicles are also becoming more connected and autonomous, transmitting significant amounts of data in real-time. Therefore, hundreds of data connectors are necessary but the connectors and sensors need to be miniaturized in order to optimize packaging space in the vehicle. The call for a tough PPA with low moisture uptake, higher elongation and weld line strength, compatibility with electronic processes like SMT (surface mount technology) and IR solder reflow, led to the development of Amodel® BIOS PPA.
Amodel® Supreme PPA and Amodel® BIOS PPA are both produced using 100% renewable energy in Solvay’s Augusta, Georgia based manufacturing plant. Our commitment to sustainable manufacturing means Solvay is the industry leader for PPA with reduced GWP (Global Warming Potential). In fact, since 2013, the GWP of Amodel® PPA has been reduced by 30%. In addition, Amodel® BIOS PPA is unique in being partially bio-based thereby further reducing GWP.
In order to overcome tighter packaging spaces in the electronic powertrain, high-performance polymers facilitate design engineers facing the challenge of miniaturizing electronic components in e-motor and power electronics systems while maintaining the same level of performance and efficiency.
Finally, specialty polymers allow designers, striving to manage overall system costs, to identify new polymer technologies that can provide the required level of performance over the lifetime of the e-mobility systems.
Introducing Amodel® Supreme PPA
Next generation design requirements for E-Motors and Power Electronics (inverters) shaped the development of Amodel® Supreme PPA. Customers are seeking improved thermal and electrical performance in their e-motor and power electronics components like bus-bars, connection rings, and also high temperature sensors. The key enabler of improving the thermal and electrical performance of Amodel® Supreme PPA is the highest glass transition (Tg) temperature for commercially available PPAs. The Tg of 165 °C, provides for excellent heat aging performance which allows Amodel® Supreme PPA to retain a higher level of mechanical performance than standard PPA products. An example of this is seen in Figure 1 below:
Figure 1: 3000 hour Heat Aging at 150 °C
The data above reveals that Amodel® AE-9933 which is a 33 % glass filled electric friendly grade of Amodel® Supreme has better mechanical property retention at 150°C over 1000 hours.
Beyond thermal performance, Amodel® Supreme was designed to provide better electrical performance at elevated temperatures than standard PPAs. The two figures below highlight how Amodel® Supreme outperforms conventional PPAs with higher dielectric strength performance as well as CTI performance.
Figure 2: Dielectric Strength Comparison
Figure 2 highlights that Amodel® AE-9933 offers better dielectric performance from 150 °C to 200 °C than standard Amodel® PPA grades.
Figure 3: Dielectric Strength Comparison
Design engineers have shared growing concerns on the breakdown of the electrical insulation material at elevated temperatures. The higher voltages and corresponding CTI performance of Amodel® Supreme is providing engineers with greater design safety freedom compared to other commercially available PPA materials.
Aside from thermal and electrical performance, Solvay needed to account for chemical resistance when Amodel® Supreme was developed. Both ethylene glycol/water and automatic transmission fluid are commonly used to cool the electric motor, power electronics, and battery. The data below in Figure 4 reflects the chemical resistance of Amodel® Supreme in commonly used automotive cooling fluids.
Figure 4: Chemical Resistance Data
|PPA Grade||Coolant @ 130°C (Water/glycol)||ATF @ 150°C||Brake Fluid @ 150°C|
|A-8000||Good||Very Good||Very Good|
In summary, automotive OEMs and tier suppliers challenged Solvay to develop a higher performing PPA which further enabled their e-mobility technologies. Solvay achieved the target by developing Amodel® Supreme PPA which provides the highest level of thermal and electrical performance amongst commercially available PPA materials. Amodel® Supreme PPA is gaining interest in next generation e-motor and power electronics applications such as bus bars, high voltage connectors, and terminals. Solvay’s portfolio of Amodel® Supreme PPA grades is shown below.
|Product Family||Amodel® PPA||Amodel® Supreme PPA (PA 6T/MCT/XXYY)|
|Standard||A-1133 HS A-1145 HS||A-8930 HS* A-8940 HS* A-8950 HS*||A-9933 HS* A-9950 HS*|
|Structural (>3 mm)||AS-1133 HS AS-1145 HS AS-1933 HS* AS-1945 HS*||AS-4133 HS AS-4145 HS||AS-1935 HS||AS-9933 HS* AS-9950 HS*|
|Electrification||AE-1133||AE-4133||AE-8930* AE-8935* AE-8950* AE-8960*||AE-9933* AE-9950*|
Introducing Amodel® BIOS PPA
Solvay took a multidimensional approach in developing Amodel® BIOS PPA. The two priorities were centered on two market needs: a higher performance PPA material for electrical connectors and the desire to reduce carbon footprints. Solvay was able to address both priorities by developing a non-competing food stock bio-based PPA solution. The technical approach resulted in the highest performing bio-based PPA solution in the market.
Amodel® BIOS PPA is a long-chained PPA with the highest Tg (135 °C) among bio-based PPAs. The long chain technology provides for lower moisture uptake than standard PPAs and higher elongation and weldline strength. These product features lend themselves to being an ideal candidate for electronic connectors, sensors, circuit breakers, switches, and solenoids. Additionally, the melting point (315 °C ) of Amodel® BIOS PPA enables the material to be compatible with standard electronic processes like SMT and IR Solder Reflow.
One of the main criteria for electric connector design engineers is dimensional stability. Figure 5 shows the superior performance of Amodel® BIOS PPA compared to Amodel® A-4000 based materials which are the current industry standard for many electronic components.
Figure 5: Water Absorption @ 24 hours and 23 °C
Other important factors that designers take into account are toughness and elongation of the connector material. These are two design inputs to ensure the connector can withstand impact and maintain its integrity over the life of the component. The impact strength shown below highlights the significant improvement of Amodel® BIOS PPA compared to conventional PPA grades used in electrical connectors today.
Figure 6: Notched & Unnotched Izod Impact Strength (ISO 180 standards)
In summary, Amodel® BIOS PPA significantly outperforms standard PPA products that are used in electrical connectors, switches, and sensors, among other electronic components. The differentiating performance of Amodel® BIOS PPA is based on material characteristics including low moisture absorption, significantly increased impact resistance and higher weld line strength. Additionally, Amodel® BIOS PPA is fully compatible with both SMT and IR Reflow soldering. Solvay’s portfolio of Amodel® Supreme PPA grades is shown below.
|Product Family||Amodel® PPA||Amodel® BIOS PPA (PA 6T/10T/XXYY)|
|Standard||A-1133 HS A-1145 HS||A-8930 HS* A-8940 HS* A-8950 HS*|
|Structural (>3 mm)||AS-1133 HS AS-1145 HS AS-1933 HS* AS-1945 HS*||AS-4133 HS AS-4145 HS||AS-1935 HS||AS R1-133|
|Electrification||AE-1133||AE-4133||AE-8930* AE-8935* AE-8950* AE-8960*||AE R1-133|
|Flame resistant||HFFR-1133||HFFR-4133||HFFR R1-133 HFFR R1-145|
Solvay developed two new breakthrough PPA solutions, Amodel® Supreme PPA and Amodel® BIOS PPA to address next generation e-mobility designs. Both solutions have best in class performance compared to conventional PPAs used in similar electronic components in e-motor, power electronics, connected and autonomous systems. Lastly, with our aim to make sustainability an integral part of the entire value chain, Solvay shares the commitment of our customers to reduce the total carbon footprint of the e-mobility industry. So, by reducing the carbon footprint of Amodel® PPA, we are also helping our customers reduce their carbon footprint.