Painting of exterior automotive parts, such as fenders, bumpers, tank flaps, grilles, mirror housings, and rear quarter panels, is complicated by the necessity of separate operation lines for metallic and polymer components, as plastics are insulative. This generally makes in-line electrostatic spray painting impossible, leading to additional costs while slowing down the entire painting process.
Consequently, automotive part makers normally select temperature-stable thermoplastic grades and modify these systems with electrically conductive additives. Carbon black is commonly used as a conductive additive. However, because of high dosage requirements, car end parts with additives demonstrate compromised mechanical properties and processing challenges.
As an alternative, OCSiAl, the world’s largest manufacturer of single-wall carbon nanotubes (graphene nanotubes), has launched Tuball Matrix 822 graphene nanotube concentrate. The product is specifically designed for polyamide (PA), filled polyphenylene sulfide (PPS), acrylonitrile-butadiene-styrene (ABS), thermoplastic polyurethane (TPU), and polycarbonate (PC) compounds for injection molding. The nanotubes create permanent, homogeneous electrical conductivity without “hot spots” in the range of 10^5 to 10^9 Ω•cm while retaining original key mechanical properties, such as durability and strength, and minimally affecting the host polymer matrix. Furthermore, a low working dosage of 0.1 to 0.3 wt.% of graphene nanotubes has only a limited effect on rheological properties and processability.
|Tuball Matrix 822 graphene nanotube concentrate.|
Graphene nanotube concentrate enables in-line e-painting of plastic exterior parts together with metal components using electrophoresis. Previously, this required separate production lines. Manufacturers of plastic injection-molded parts for automotive, industrial, construction, mining, and other applications now have the opportunity to reduce production costs and reject parts without changing standard operating processes by using high-performance graphene nanotubes.
“The new product will also be valuable for improving automotive safety and tracking systems,” said Vladimir Kravchenko, Development and Support Leader for Thermosets, OCSiAl Group. “Graphene nanotubes allow makers to produce high-quality electrically conductive thermoplastic products without compromises in terms of overall mechanical performance or durability. We already see demand from manufacturers of fuel system parts including quick connectors, fuel pumps, valves, filter housings, EV-battery caps, and other car components,” said Kravchenko.