Injection-Molded Breakthroughs Highlight SPE Winners

Engineers at Delphi Automotive last week were awarded the grand prize in the 39^th Society of Plastics Engineers' Automotive Innovation Awards Competition for their development of an injection-molded plastic radio housing.

The new radio case, which replaces a formed sheet metal case, is being used first on the mid-year model of the GM Tahoe.The new case achieves  EMI and RFI shielding by completely enclosing electronics with a mesh Faraday cage that is insert molded using patented magnetic tooling.

"The biggest advantage is the reduction in weight. There is a 1.2  pound, or 22 percent, weight savings," says Vineet Gupta, who led the engineering team that developed the technology. 

The other awards are listed below, by category:

Body Exterior: Exterior spoiler with integrated stop light assembly is used on the  Cadillac® CTS® Sport Wagon.

Highly dimensionally stable, this thermoplastic Class A horizontal body panel meets stringent gap requirements by managing a low coefficient of thermal expansion (3.9) while also maintaining heat, impact, and surface quality for a highly aesthetic application.  The center-high-mounted stop light is also integrated in this part.

Body Interior. Plastic post-isolation for automotive HVAC blower motors is  used on the  Chevrolet® Camaro® Sports Car.

This application uses an integrally molded plastic mount instead of multiple rubber isolators to soften and quiet HVAC fan-motor vibrations, resulting in significant reductions in cost and development time plus a quieter vehicle interior for consumers.  A resonant frequency "tuning" feature allowed for noise/vibration/harshness (NVH) optimization even late in the vehicle-development cycle with minimum impact on mold tooling.  Now bare motors can be purchased, allowing more motors to be shipped per container, and a quick snap-fit joins the plastic mount to motor, facilitating assembly.

Chassis & Hardware. The winner for this category is electric power-steering flexible coupling used on the Fiat® 500 Compact Car.

This flexible plastic coupling for the vehicle's electric power steering replaced a similar stainless-steel coupling with broached splines and grease.  The part features ribs that connect and transfer torque from one rotating shaft to another, which in turn strokes axially and stretches and compresses the coupling. The fully compliant constant-velocity joint eliminates torsional lash, the need for grease, and all sliding interfaces at a cost savings, while reducing audible cabin noise and improving steering "feel."  The system replaces traditional hydraulic systems, reducing weight 17 percent, cost 50 percent, and increasing fuel economy by 4 percent.  System performance and customer satisfaction were also improved.

Environmental. Radiator end tank from renewably sourced material, which  was developed for the Toyota® Camry® Sedan.

This is described as the first use of bioplastic in a chemically aggressive and mechanically demanding application - in radiator end tanks.  Roughly 40 percent of this new nylon 6/10 material is sourced from caster bean oil, reducing reliance on petroleum-based inputs and helping lower the vehicle's carbon footprint.

Materials. Door panels made from natural-fiber composite are used on theBMW® 7 Series Luxury Sedan.

This lower door-panel inner was compression molded from a new, high-performance, lightweight, cost-effective, and green composite.  The resin matrix is a unique acrylic polymer that is thermoplastic in its "B-stage," allowing for production of prepreg/semi-finished rollstock or blanks, yet cross-linking at temperatures above 120C to produce a very durable thermoset. 

The resin's high "wet-out" of natural fibers and ability to form chemical as well as mechanical bonds to the reinforcement allows for production of composites with very-high fiber loadings - 70 percent in this application - yielding lightweight parts with high stiffness in thin walls. The resulting panel saves weight and cost, significantly reduces VOC emissions, and its rapidly renewable natural fiber mat reduces the vehicle's carbon footprint without sacrificing performance.

Performance & Customization. Illuminated door-sill inserts using a single-LED light engine was engineered for the Ford® Mustang® Sports Car, Lincoln® MKZ and Ford® MKT Sedans.

The insert combines several different plastic technologies to create optics that require only one LED light source. It is described as easily be customizable (via laser etching) to produce high-impact illuminated graphics. The system's unique construction allows the design to be adapted to new vehicles in weeks, not months, significantly reducing development costs. In addition, the application is the auto industry's first to provide multi-color illumination from a single LED light engine.

Powertrain.  An oil pan optimized for stone impact with an impact-modified, 35 percent-glass nylon 6 was developed by BASF for Ford's 6.7L power-stroke turbo diesel engine.

Plastic oil pans have been a design goal for more than 20 years. This is the first plastic oil pan designed for full exposure to the road environment and optimized to withstand road chemicals and stone impacts thanks to a new material / ribbing configuration. 

The new BASF resin is not affected by calcium chloride due to a proprietary modification package. A special waffle-design ribbing pattern can handle multiple impacts (unlike earlier plastic designs with sacrificial ribs).  Another unique aspect of this oil pan is that it features the first plastic drain plug, which sports a cam-lock design that makes it impossible to over-torque and break the plug's screw threads. The oil pan is 2.1-lb lighter than the steel pan it replaced and 30percent less costly.  It has a noise/vibration/harshness value similar to that of cast aluminum and quiet steel, yet will not rust or corrode and provides better protection against stone impact than metal designs.

Process / Assembly / Enabling Technologies. The winner is the plastics radio case, which was awarded the grand prize.

Safety. A pedestrian-protection-compliant front fender was engineered for the Ford® Kuga® Compact CUV.

This is the first SUV with thermoplastic fenders that meet European pedestrian-protection requirements for head impact in a single part, eliminating the need for secondary brackets under the fender as in steel designs. The resin system used is a proprietary grade from Sabic Innovative Plastics that includes polyphenylene ether, polystyrene, and nylon. Weight and cost are reduced by 50 percent compared to steel, according to Ford.