The 2003 Restriction of Hazardous Substances Directive (ROHS) had a big impact on the ability to make brightly-colored Polyamides (PA), as it banned all pigments containing certain substances like cadmium and chromium – pigments that are thermally highly stable. It took many years of hard work on developing a PA formulation with alternative color additives, including Technyl® Orange for high voltage applications in EVs in 2016.
“We started with polyamide products for electrical and electronics industries that were dark colored, because darker shades are less complex to design, stabilize, laser-mark, and so on,” says Xavier Couillens, New Business Development Manager C&E. “The lighter and brighter the color, the more technical expertise required.”
Color complex
In 2010, a major OEM in Electric & Electronics market asked Technyl® to develop an HFFR polyamide in the color white, with white color stability retention under temperature, laser-marking and other capabilities that made this a worthy experiment. The Technyl team then took that experience and applied it to making PA in other colors, including orange, which is even more complex. This is because the color needs to be stable and the RoHS directive bans the most thermally stable color additives suitable to design orange colors.
The complexity of handling light and bright colors is also linked to the temperature required during all transformation processes (compounding and molding). The higher the temperature required for melting and processing, the more complex and fewer color additives (pigments and colorants) possible.
Thus, there are more pigments and colorants available for lower melting polymers such as polypropylene or polybutylene terephthalate (PBT) than for polyamides (especially PA 66 and high-temperature nylon like Technyl® ONE ). However, polypropylene is less stable and not able to withstand high temperatures and PBT is brittle, and even more so when combined with halogen-free flame-retardant (HFFR) systems.
Tools of the trade
Polyamides formulated for high temperature applications provide superior mechanical performance, high heat and fatigue resistance, superior electrical performance, easy processing with low mold deposit, and can be formulated for fire retardancy properties for consumer & electronics applications as well as high voltage applications in automotive.
Technyl® ORANGE, when combined with halogen-free flame-retardant systems, furthermore, responds to the electrical needs for the automotive market, as an alternative to PBT halogen and halogen-free flame-retardant materials, combining both safety and performance while enabling parts miniaturization for EV applications, including UL certifications. The Technyl team has built this expertise over several decades, as one of the very first suppliers of HFFR polyamides, supplying HFFR materials to the building and construction industry for more than 20 years.
“We surveyed the market for all pigment and colorant players and possible color offerings and created a toolbox to build our understanding of the color additives’ behavior for tailor-made solutions for the most important applications for our customers,” says Xavier.
Market cred
While achieving the color orange was one challenge, even more important and challenging was to ensure color stability, so that the orange color retains its shade and the safety connotations associated in high temperature environments for the lifetime of the vehicle.
“Our Technyl Orange products are quite unique because of their development process via our orange toolbox solutions, and this allows us to have an advantage compared to other players, because we master all the technical levers (such as color, color stabilization, laser-markability, flame retardancy,…) to be applied to better serve the technical applications needing orange colors.” he adds. “This gives us credibility in the market.”
As an example, the team is developing a Technyl® Orange formulation for an e-mobility connector supplier. This customer has had many issues with their orange PA preparation including mold deposit, which leads to quality issues and unnecessary wastage in processing. Thanks to their extensive expertise on this issue, the Technyl® team was able to provide a tailormade product for this customer that was markedly higher-performing than the previous product. In addition to improving the deposit issue, the team has offered a solution that also best retains the orange color under temperature, guaranteeing one of the main security functionalities for a high-voltage connector. “A two-in-one benefit, with accurate quality and retained safety,” says Xavier.
It was a similar story for another automotive tier supplier requiring an HFFR PA solution and was having an even more complex issue with mold deposits as the deposits were due to a combination of a non-appropriate coloring agent and a non-accurate HFFR system selection. Combining the Technyl® Orange toolbox and our knowledge in the field of HFFR tailored solutions, the team could apply various levers for this client’s specific application, to considerably improve processing and lower mold deposit. “Thanks to our experience, we were able to provide a formulation that was optimized in terms of orange color and HFFR for this customer’s needs,” he says.
Polyamide pedigree
From a technical perspective, Xavier suggests that orange would never have been selected by engineers knowing the complexity of the formulation to achieve it. Another color like, yellow, blue or green would have been easier. Orange is the most challenging color for polyamides.
“This is a major differentiator in the market in terms of players who are able to achieve this complexity,” adds Xavier. “Because, at Technyl, we are focused on polyamides only, we have a pedigree in terms of our experience and expertise in this complex material to tailor it and combine a demanding orange color with even more demanding electrical, flame retardant, and mechanical properties.”
Discover what Technyl® Orange can do for you and get in touch with the Technyl® team to harness the full capabilities of this new range of polyamide products for your high-voltage component and cabling needs!