How New Technology in Injection Molding is Advancing Vehicle Lightweighting

Vehicle lightweighting has fast become a leading growth trend in automotive design and manufacturing, with lightweighting strategies playing an increasingly significant role in a burgeoning circular economy. 

Current innovations in vehicle lightweighting are focused on both materials and part design. The use of lighter weight materials in concert with innovative design and advanced fabrication options open the door to optimized structures, maximized reductions in weight, and standards that exceed both performance and safety.

Plastics are at the forefront of vehicle lightweighting initiatives for OEMs. Despite a drop in new car sales during the initial waves of the COVID-19 pandemic, according to a recent report, the global automotive plastics market is currently valued at an estimated USD$29.5 billion, with a compound annual growth rate (CAGR) of 4.7% from 2022-2030. This indicates an automotive plastics market valuation in 2030 projected to be USD$43.4 billion.1

As sustainability becomes the preeminent factor for automakers and OEMs going into the next quarter of the 21st century, manufacturers are mandated to think through circular pathways for automotive plastics. iMFLUX is uniquely positioned to address these challenges, both at the beginning of a car’s life cycle with its ability to fabricate more sustainable lightweight parts, and at the end by being able to incorporate the recycled material from older models into the manufacture of new parts for the cars of the future.

The Broad Impact of Lightweighting

In addition to reducing the overall weight of automobiles to meet the demands of more comprehensive environmental regulations — increased fuel efficiency and range per charge in electric vehicles;  lightweighting structural components is key to success, as well as broader environmental impacts beyond vehicle performance. The injection molding method is used to create significantly lighter-weight plastic parts is the same technology that will allow automakers to significantly reduce a vehicle’s overall carbon footprint during the manufacturing stage, and create the next generation of automobiles using recycled parts from older models. 

One major way automakers are embracing plastics as a critical tool to address vehicle lightweighting is with metal-to-plastic conversion. Replacing heavy metal parts with lighter-weight injection molded plastic components, engineered and fabricated to meet the same durable structural standards as their metal counterparts, addresses a number of challenges, including increased fuel efficiency, lower emissions, and a reduction in both operational and manufacturing costs. 

iMFLUX’s revolutionary low-constant-pressure injection molding platform is the perfect solution for carmakers on the cutting edge of vehicle lightweighting. Not only does the system address the manufacturability limitations of high-velocity, high-pressure injection molding, but it allows designers freedom to engineer thinner-walled, lighter-weight parts previously unimaginable using conventional methods. 

By lowering filling pressure in many cases by 25% or more, the technology allows the material to enter the mold without hesitation in a single-phase with no transfer, and pack as it fills.  The result is a significant part weight reduction. Further, by employing iMFLUX’s Edison Award-winning Auto Viscosity Adjust™ (AVA) feature, OEMs can utilize a variety of highly variable materials for thin-walled applications, including PCR material streams. In addition to lightweighting, the technology improves the quality of the part — virtually eliminating ghosting, tiger striping, sink, warp, or dimensional instability — but it also produces less plastic scrap, lowers energy consumption, and results in marked increases in cost efficiency.

Improved Efficiency and Design Freedom

Conventional materials used to build automobiles, even the lighter aluminum alloys that replaced steel parts generations ago, suffer not only from being heavy but any benefit received from their durability comes at the cost of rigidity in material and design. Over the years, the use of plastics has become the go-to solution to surmount design hurdles and increase automobile efficiency. Now, advances in the injection molding process are poised to bring a further paradigm shift in automotive design and manufacturing.

As automakers increasingly prioritize sustainability, plastics play a leading role in the drive toward more efficient vehicles. Lightweighting for gasoline-powered and hybrid automobiles is driving up their miles-per-gallon averages. With the rising cost of gas, not only are these more fuel-efficient cars better for the environment, they’re more marketable to cost-conscious consumers as well. 

Electric vehicles, however, are the main beneficiaries of advancements in vehicle lightweighting. Many governments around the world are focused on converting to zero-emissions fleets as soon as 20352, with car manufacturers like Renault vowing to only sell all-electric vehicles in the European market as soon as 20303. As automakers design the EVs of the future, the focus on lighter-weight cars means a single charge will result in longer distances without having to increase battery size.

In order to accomplish these efficiency goals, car designers are innovating parts that are lightweight by design and made from advanced materials. Until recently, many of their ideas had to remain on the drawing board as limitations in manufacturability put a ceiling on innovation.

iMFLUX has emerged as a leader in OEM part design and fabrication with its low-constant-pressure injection molding system. The platform retrofits easily onto existing injection molding equipment, whether they’re hydraulic, electric, or hybrid. While parts made using iMFLUX in concert with existing molds see a 1%-3% decrease in weight, auto parts made with molds designed specifically for iMFLUX can reduce weights much more significantly by 25% or more in some cases. 

To accomplish this, iMFLUX fills molds slower and with a lower pressure, allowing the polymer to pack the mold as it fills. Because the part is essentially completely packed when the mold is full, there is no need for a holding phase to force in more material, thereby automatically reducing part weight. 

Lightweighting and the Circular Economy

As OEMs embrace injection molded plastics as an innovative solution to the need for lightweighting, iMFLUX offers them a tool to design lightweight parts that were once impossible to manufacture with conventional injection molding methods and a way to do so using less energy, generating less scrap, and realizing greater cost savings.  

Further, this groundbreaking technology opens up the viability of highly variable materials for use in auto parts manufacturing. The use of PCR streams in conventional high-velocity, high-pressure molding often resulted in inconsistent part quality while costing manufacturers more. iMFLUX uses its AVA technology to automatically adjust for variability in material viscosity, reducing material scrap and cost.

Beyond the immediate advantages of adopting a low-constant-pressure injection molding platform, the longer-term benefits with regard to the entire lifecycle of the automobile are also significant. Currently, as much as 30% of a vehicle’s lifetime CO2 emissions are generated before the vehicle even hits the road. As a manufacturing solution focused on energy savings, using iMFLUX technology can dramatically reduce the lifecycle impact. 

The automotive industry is experiencing a major evolution with the critical focus on greater fuel efficiency, longer EV range, and the role auto manufacturing plays in a circular economy. As environmental regulations increase, automakers need groundbreaking advances like the iMFLUX injection molding platform to help them move the sustainability revolution forward.