A Look at the Future of Lightweighting

Lightweighting is no longer optional. All over the world, the goal of material and design engineers is to design and build multi-material lightweight automotive vehicles in high volume while providing the same or greater levels of safety and durability. OEMs are exploring materials such as anodized aluminum, plastics, carbon fibers and others for reducing vehicle weight while expanding their design possibilities. A recent study (PDF, 1.3 MB) by McKinsey shows that by 2030, the use of lightweight materials in automotive production will approach the levels currently used in aviation.

Seating in particular is a focus for lightweighting in automotive interiors. As OEMs look to suppliers to create solutions, many are taking the challenge to heart. Faurecia, for example, has been working with a Chinese automotive foundry to develop seat structures made from magnesium alloys. According to Automotive IQ (PDF, 618.3 KB) the company estimates the material could result in a 25% weight reduction compared to previous steel seating structures.

Meanwhile, Adient recently unveiled several multi-material seating concepts including die-cast magnesium seat structures, glass fiber–reinforced plastic front seat backrests, and aluminum and high tensile steel back seats with a goal of reducing standard seat structure weight by 22 pounds by 2020.

Efforts like these present some interesting questions for OEMs, tiers, converters and their suppliers. Challenges remain to cost-effectively bring lighter, multi-material solutions into production. The central question is: we can create new solutions, but how can we implement them?

Part of the answer is, literally, in the nuts and bolts. As lighter materials such as high strength steel, aluminum and magnesium are concepted and introduced in automotive designs, the need to bond them effectively becomes paramount. At the same time, OEMs are constantly looking to make the manufacturing process more efficient, often with innovative products that can reduce process time or eliminate steps. All of this creates opportunities for the development of alternatives to traditional fastening methods like spot welding, bolts, rivets and clinching.

The chart above from CAR Research/Lucintel shows what’s likely to happen in the coming years. The expected growth in automotive adhesives is unmistakable. According to Lucintel, the overall automotive adhesives market has been forecast to grow at a CAGR of 9% from 2015 to 2020.

Tapes and structural adhesives can provide lightweight solutions along with – or in place of – traditional fasteners such as rivets, bolts or screws. In a recent white paper, Adhesives.org and Sealants.org (PDF, 949.4 KB)  point  out that structural adhesives in particular can help stiffen structures when added to weld lines and seams, as well as seal gaps which can reduce NVH. The organization also says it expects the average structural adhesive bond length per vehicle to increase 60% over the next five years (approx. 2020) to an average of nearly 90 linear feet per vehicle.

It’s always important to consider whether an adhesive is appropriate for certain applications.  For example, many panel bonding adhesives are intended for use in outer body, non-structural panel attachment applications, including such applications where they are used in conjunction with welding and/or riveting.  There are many factors that can affect the structural integrity of an individual design, so automotive engineers should always evaluate an adhesive to determine what is appropriate. Several adhesive manufacturers offer what are called impact-resistant structural adhesives, which can also be evaluated for use by OEMs. 

Plastics and fiber-reinforced composites are becoming increasingly popular for seating concepts, instrument panels and other areas. Suppliers like 3M are developing adhesives and tapes that can permanently bond a great many plastics and composites as they become increasingly practical – and even necessary. These products allow you to bond plastic to metal, low surface energy (LSE) substrates and dissimilar materials.

Additional advancements in materials for lightweighting include those for reduction of interior NVH. These materials, generally inserted into cavities in doors or headliners, are much lighter and higher performing than in past decades. 3M™ Thinsulate™ acoustic absorbers feature a blown microfiber web that yields excellent performance at a wide variety of weights and thicknesses where noise and mass reduction are major goals.

The automotive landscape is rapidly changing worldwide. It’s imperative for OEM material and design engineers to continuously incorporate lighter, stronger materials into automotive interior designs. At the same time, other trends such as autonomous driving, electrification and ride sharing are emerging in growth markets across the globe. For bonding, joining, insulation and sound absorption, 3M delivers products and solutions to help OEMs, tier suppliers and converters meet the demand.