Evonik Degussa Corp.
Sabic Innovative Plastics
Solvay Advanced Polymers
Blow Molding for Air Handling
The 2.0-liter four-cylinder turbocharged engines found in several BMW modelsâincluding the 4, 5 and 7 Series, and the X3, X4, X5âare being fitted with a blow-molded charge air duct (it goes between the turbocharger and the charge air cooler) that is being produced by MANN + HUMMEL (mann-hummel.com) with a high-temperature polyamide, Ultramid Endure D5G3 BM, from BASF (basf.com). It is a polyamide 66 material that has 15 percent glass fibers.
In this application, the component is subjected to both heatâit is temperature resistant up to 220Â°C in continuous use and up to 240Â°C peak loadsâand pressure: as the duct channel compressed hot air from the turbocharger to the integrated charge air cooler, pressures higher than 2.5 bar can be achieved.
While charge air ducts are sometimes made with hydroformed rolled aluminum sheet, the blow molding process lends itself to providing the varying shapes that are required to fit within the compact space required on the engine. And compared with other plastic materials, the interior surface of this polyamide 66 is said to be smoother, which facilitates air flow.
And speaking of other plastic materials, polyphenylene sulfide, which is used to produce ducts, doesnât have the same acoustical properties that the BASF material does: according to the company, depending on the temperature and humidity levels, it offers damping values up to 10X better than polyphenylene sulfide.
In terms of attaching the duct to other parts, this can be performed with processes like infrared welding. Although with the low glass fiber content it might seem that the weld line would be a weak spot, there is a stabilization mechanism in the Ultramid Endure BM that helps strengthen the area: it has been determined that after 1,000 hours at 220Â°C, there is no cracking at the joint.
Stiffer than Metal
According to Borealis (borealisgroup.com), its carbon fiber reinforced polypropylene (PP) grades, Fibremod, offer stiffness as high as 20,000 MPa and an extremely low density. In this regard, it can outperform aluminum and magnesium and provides a light-weighting potential, compared with steel, of more than 60 percent. Included in its portfolio are a number of Fibremod grades that have varying levels of carbon fiber reinforcements in its PP. Applications for these materials range from headlamp housings to oil pans to seat frames to gear-shift gates.
BASF (basf.com) has developed a new polybutylene terephthalate (PBT) grade specifically for applications such as wire harness connectors. The material, Ultradur grade B4340ZG2 High Speed (HSP), has high flowability for molding and good impact strength for application. It also features good electrical properties which allow minimum distances between the conductor tracks in plug-in connectors.
Formed with Color
The high-gloss, piano-black A-pillar trim pieces for the Peugeot 3008 SUV are being produced within one minute in a molding operation being performed by a Swiss supplier, Weidplas GmbH, via the ColorForm process developed by KraussMaffei (kraussmaffei.com).
In the operation a thermoplastic base body is formed in a mold; it is flow-coated directly in a second cavity with a two-component polyuria or polyurethane paint.
The operation is being performed at Weidplas with a KraussMaffei SpinForm GXW 650-1400/2000 injection molding machine that has a clamping force of 6,500 kN.
The parts are long and narrow: one meter long and 35-mm wide.
After being molded, they are handled by a Kuka IR 1500 robot. Ultrasonic welding is used to attach the cover toÂ seal carriers.
Thermoplastic for Transfer Molding
Glass fibers. Carbon fibers. Aluminum. Steel. Thermoplastic (Polyamide 6). All of these materials are combined in the frame for the roof shell used for the Roding Roadster R1 sports car in a process developed by KraussMaffei (kraussmaffeigroup.us). The metal components are setup and assembled, then placed in a mold along with the fabric where T-RTMâthatâs thermoplastic resin transfer molding, as distinct from the more familiar RTM, which uses an epoxy resin or polyurethaneâis performed.
There are two caprolactam components injected into the moldâone is a base material and the other the catalyst. Because the matrix material has a low viscosityâfive millipascal-secondsâit readily wets the fiber layers even though there are comparatively low clamping forces (e.g., 3,500 kN) applied. The T-RTM process lends itself to producing near-net-shaped parts, which minimizes material waste.
Whatâs more, parts can be made with very thin walls.
Another benefit for applications like the roof frame is that the PA6 material that is used has both higher impact strength and ductile fracture behavior than thermoset plastics, which means that it can absorb more impact before fracturing occurs.
How is the Batmobile Like A Saturn SL1?
One of the more-interesting plastics-based automotive developments of late is, well, a Batmobile, specifically a LEGO Batmobile from Chevrolet, inspired by the Batman Speedwagon in The LEGO Batman Movie.
The vehicle is produced with 344,187 LEGO bricks. LEGO bricks are, of course, made with plastic, acrylonitrile butadiene styrene (ABS) plastic, for the most part.
Like the Saturn S-models (1991-2002, which means the period of Michael Keaton, Val Kilmer and George Clooney as Batman), the LEGO Batmobile is constructed on a frame. In this case, it is a frame produced with approximately 86 feet of square tube aluminum that weighs 282.5 pounds.Â The total weight of the vehicle is 1,695.5 pounds.
Know that it is 83 inches high, 204 inches long and 111 inches wide.Â The Batmobile was designed and built in the LEGO Model Shop in Enfield, Connecticut, by LEGO Master Buildersâwho spent 222 hours designing it and 1,833 hours assembling it.
Plastic oil pans arenât new. But given their locationsâright above the road surfaceâthey are certainly vulnerable to impacts from stones and other debris, which can cause all manner of problems for motorists should there be a crack in the pan.
LANXESS (lanxess.com) has developed a new material specifically for application in oil pans: Durethan BKV 235 H2.0 XCP. The last three letters stand for âExtreme Crash Performance.âÂ It is a polyamide thatâs rubber modified and reinforced withÂ 35 percent special short glass fibers.
According to the company, at -30Â°C, the Charpy notch impact resistance of the new material is 18 kJ/m2 (ISO 179-1eA). By way of comparison, the companyâs standard polyamide 6 with 35 percent glass fibers, Durethan BKV 35 H2.0, impact resistance is 10 kJ/m2 at -30Â°C.
Whatâs more, the XCP grade is exceedingly close to the standard polyamide 6 as regards e-modulus and tensile strength at break, meaning that the molded component can be stiff, strong and exhibit high impact resistance.
And it is good in the heat, too. The heat distortion temperature to ISO 75-1,-2 (HDT A, 1.8 MPa) of 203Â°C is nearly as high as that of Durethan BKV 35 H2.0.
Process for Affordable Composite Parts
Can composite materials move from high-end autos to more mass-produced vehicles? According to Evonik (corporate.evonik.de), its newly developed process, PulPress, may make this happen.
PulPress combines compression molding and pultrusion.The process begins with a structural foam core, made with the companyâs ROHACELL material, thatâs wrapped with woven fibers before impregnation with resin. This is then compressed, under high temperatures and pressures, to the required shapes, which can be complex geometries and even include recesses.
The parts are said to provide good crash characteristics. They are also about 75 percent lighter than comparableÂ steel parts.
And what probably goes to the point of being used for an array of vehicles, not just luxury: the cost of producing a part with PulPress compared with typical resin-injection processes is up to 60 percent less expensive.
Fiber (Carbon) is Good for Autos
A variety of composite materials focused on automotive has been developed by Hexcel (hexcel.com), such as HiMax carbon fiber multiaxial fabrics that are specifically optimized for high-volume part production, as in being a non-crimp, high-drape fabric that can conform to complex mold geometries while offering the permeability required for fast resin injection and cure times.
There are prepregs, such as the HexPly M77, which cures in 1.5 minutes at 160Â°C. This material is being used by BMW for the 7 Series.
The HexPly M77 material is also being used by British supplier St. Jean Industries to produce a suspension knuckle that is an aluminum structure that is stiffened with the carbon fiber reinforced plastic material, thereby increasing stiffness (compared to aluminum-only) by 26 percent. The prepreg stacks are bonded to the aluminum with a fast-curing film adhesive, Redux 677, which fully cures in four minutes at 150Â°C (at 3.5 bar). The film adhesive can also be used to bond HexPly M77 to other metals, thermosets and thermoplastics.
Worldâs LargestÂ PC Rear Windows
According to SABIC (sabic.com), the rear quarter windows that are being deployed on the new China-market Buick GL8 and GL8 Avenir crossovers built by SAIC-General Motors feature the worldâs largest polycarbonate (PC) rear quarter windows.
The window measures 1,200 mm xÂ 450 mm.Â Molded from LEXAN resin, the rear quarter window is 40 percentâor 3 kgâlighter than a comparable glass window. And more impact-resistant.
The windows are being molded by Ningbo Shentong Auto Decorations (shentong.en.chinaningbo.com), which installed a new production facility for PC glazing, in a two-shot injection compression molding process: in addition to the PC for the transparent area, there is CYCOLOY resin, a PC/acrylonitrile-butadiene-styrene (ABS) material used for the blackout area.
Jun Luo, Shetongâs deputy general manager, said, âIn addition to significant weight reduction, PC glazing allows for greater innovation than is now possible in glass, like design and styling freedom, thermal efficiency and parts integration.
Plastics Under the Hood
The Polimotor 2 is the brainchild of Matti Holtzberg, president of Composite Castings, who wants to create a 2.0-liter, 350-hp turbocharged four-cylinder racing engine that is significantly lighter than standard enginesâon the order of 140 pounds, or about 90 pounds less than conventionalâthanks to the extensive utilization of polymer materials in place of metal. (Yes, even the engine block is a composite, not a metal.)
Solvay (solvay.com) is one of the key suppliers to the project, with its materials being used for:
Â â¢ Cam sprockets: TorlonPAI 7130 30 percent carbon fiber
Â â¢ Oil line scavenger: KetaSpire PEEK KT-820 CF30 30 percent carbon fiber
Â â¢ Water outlet: AmodelÂ® PPA A-8930 HS 30 percent glass fiber
Â â¢ Water outlet seal: Tecnoflon FKMÂ PL 855
Â â¢ Fuel rail: Ryton PPS XK-2340 40 percent glass fiber
Â â¢ Oil pump: AvaSpire PAEK AV-651 CF30 30 percent carbon fiber,
Â â¢ E-water pump: Ryton PPS R-4-220Â 40 percent glass fiber
Â â¢ Cam cover Radel PPS R-5500
One of the interesting technical developments is the plenum chamber. This is being made with Sinterline Technyl, a polyamide 6 powder with 40 percent glass beads. It isnât being molded, but it is being 3D printed with selective laser sintering.
However, before printing the part, they applied a predictive simulation program to the part. Called MMI Technyl Design, a service powered by Digimat from e-Xstream, an MSC Software company (mscsoftware.com), the simulation showed that the original plenum design could be 30 percent lighter without sacrificing performance parameters. As Holtzberg, who is also the lead designer of Polimotor 2, puts it, âIntegrating the 3D printed part with predictive simulation demonstrated all the additional benefits we could obtain to further reduce weight.â Â Â