The Power of Two Materials: Plastic Meets Metal

Emission regulations are becoming more stringent. For the entire automotive industry—manufacturers and suppliers—it‘s an enormous challenge. Polymer metal hybrids from ElringKlinger combine maximum functionality with minimum weight—a combination that is in demand.

By ElringKlinger and Lightweighting World Staff

Lightweight design is a tradition at ElringKlinger. Series production of the first plastic lightweight component, a valve cover, was launched at the end of the 1990s. The product portfolio expanded continuously throughout the years. The company also succeeded in entering lightweight design for body and chassis parts. In hydroform hybrid technology, plastic meets metal. An optimal combination of materials.

Tough Guy

The standards expected in terms of functionality, safety, stability, environmental compatibility, design and comfort are already high, but they will continue to rise. To be able to offer customized lightweight parts in the vehicle-body sector, as well, it is all the more important to have comprehensive expertise in materials, processes and production.

An optimal material combination, in conjunction with joining technology, is crucial for hybrid lightweight design because the strengths of the two materials complement each other: weight saving, high shape and dimensional accuracy, increased structural rigidity in the event of a crash, realization of complex geometries, reduced number of individual parts due to multifunctionality, time saving from the integration of multiple process steps in a single operation, less material input and consequently, lower costs—the list of benefits is long.

Structural components, such as the cockpit cross beam or front-end carrier, are manufactured in a world-leading production process that combines internal high-pressure forming and injection molding in a single step.

A thin-wall aluminum tube made in an extrusion process is placed in a mold by automation.When the two parts of the mold are closed, the interior of the tube is filled with liquid and pressurized, thus acquiring its precision final contour. Then the injection molding process begins in the same mold cavity. Molten plastic is injected into the mold at the appropriate temperature and pressure, where it solidifies in the cavity around the deformed tube. After that, the hybrid component is automatically removed and transferred to downstream machining processes.

Metal and polymer are joined making a positive connection and frictional connection. The injection molding compound is forced onto an aluminum tube that has been serrated. It clings to the serration, and the tube is coated, in addition.

This technology has been used at three ElringKlinger sites so far: Fremont, Calif.; Suzhou, China; and in Leamington, Canada. The required 32-ton molds are made by the group‘s mold-making division, Hummel-Formen, in Lenningen, Germany.

Lightweight Design Solutions for Front Module and Cockpit

In the vehicle body department, the first step is to produce the cockpit cross beam and the front-end carrier using polymer-metal hybrids. A cockpit cross beam from ElringKlinger combines maximum functionality with minimum weight. It carries, for example, the instrument panel, steering column, heating and ventilation modules, airbags, glove box, center console and other equipment elements, and connects them securely to the vehicle body.

Cockpit cross beams from ElringKlinger combine maximum functionality with minimum weight. They carry, for example, the instrument panel, steering column, heating and ventilation modules, airbags, glove box, center console and other equipment elements, and connect them securely to the vehicle body.

More to the front of the vehicle, a front module, which is also of hybrid design, carries the intercooler, the headlamp modules, the splash water tank, the signal horn and the proximity regulating radar module. It also supports the engine hood.

The hybrid design front-end section can be used as a support for the intercooler, headlamp modules, windscreen-washer reservoir, horn, distance radar module or air intake. It also supports the hood. To reduce the overall weight, ElringKlinger relies on a combination of polymer injection molding, metal sheets and metal tube hydroforming.


Thinking Ahead: Engine and Transmission Carriers Made of Glass-Fiber
Reinforced Thermoplastics

As a plastic injection molding specialist, ElringKlinger is going one step ahead with engine and transmission carriers, replacing the metallic materials used to date with glass-fiber reinforced thermoplastics. Engine carriers made of glass-fiber reinforced polyamide have crucial advantages over conventional aluminum designs. Better acoustics, higher thermal insulation and a significant weight advantage speak for themselves. Components are also characterized by high strength and rigidity. In addition, the engine mount made of natural rubber is better protected against engine heat and thus prolongs service life. Inserts and bushings, but also heat shields, can be integrated without any problems.

Versatile—Structural Components Made of Continuous Fiber-Reinforced Thermoplastics

Use of continuous fiber-reinforced thermoplastics in conjunction with thermoplastic injection-molding makes it possible to replace metallic components, even in structural parts of the vehicle body and interior. As a result of this material combination, crash-relevant parts can have plastic components. This has been demonstrated by initial design studies that were conducted at ElringKlinger.

In a single-stage process, the warm organic sheet is placed directly in the injection mold, shaped when the mold is closed and finally subjected to direct injection. The good material properties of the organic sheet are further improved by injecting rib structures. Due to the option of function integration, a multi-component metallic part can be turned into a thermoplastic part. The numerous potential applications of continuous fiber-reinforced thermoplastics are amazing. There are also possible uses in the non-automotive sector.

Everything from a Single Source

There is one special benefit that ElringKlinger offers its customers. Development and design of components, tooling and the associated process development come from a single source. From the customer‘s first telephone call to mass production of components, everything is coordinated with each other, providing low-cost, rapid and flexible component development and production.

produce the structural components—also known as polymer-metal hybrids (PMH)—ElringKlinger uses a combination tool that performs hydroforming and plastic injection molding in just one process step.

This is ElringKlinger

As an automotive supplier, ElringKlinger has become a trusted partner to vehicle manufacturers—with a firm commitment to shaping the future of mobility. Be it optimized combustion engines, high-performance hybrids or environmentally friendly battery and fuel-cell technology, ElringKlinger provides innovative solutions for all types of drive systems. ElringKlinger’s lightweighting concepts help reduce the overall weight of vehicles. As a result, vehicles powered by combustion engines consume less fuel and emit less CO2, while those equipped with alternative propulsion systems benefit from an extended range. These efforts are supported by a workforce of more than 8,800 people at 49 ElringKlinger group locations around the globe. More information is available at








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