Consumers want fuel efficiency and government regulations demand it. The trouble is, other consumer preferences, along with government standards addressing additional aspects of vehicle construction, can make the task of achieving fuel efficiency very difficult for auto manufacturers. For example, consumers continue to show a preference for heavy vehicles such as vans, trucks and SUVs. Safety regulations can also require heavy materials for vehicle frames.
The good news is that some vehicle panel assemblies—such as liftgates—can be made lighter. Here are three ways to do it:
- Switch to aluminum. Aluminum is a lower density metal than iron or steel and can be used at thinner gauges while still providing high strength. Therefore, aluminum alloys are increasingly used in auto body panels. A barrier to adoption, though, is that welding aluminum is tricky. Aluminum conducts heat much faster than steel, which means more energy must be put into the weld. Yet aluminum has a relatively low melting point, so it can experience warping or burn-through. Additionally, aluminum wire is soft enough that it can feed poorly through a welding gun. Adhesives solve these problems, allowing panels to be bonded and sealed in one step while creating a strong structural bond.
- Switch to plastics. Plastics are exceptionally lightweight. However, some of the best performing and most widely used are thermoplastics, such as polypropylene (PP), polyvinyl chloride (PVC) and some polyurethanes (PURs). Thermoplastics, by definition, can be repeatedly softened or melted by heating and hardened upon upon cooling. Welding, especially when joining two different plastics, presents a big challenge, since chemical incompatibility or different melt temperatures come into play. Welding incompatible thermoplastics becomes a chemistry problem: polymer blends must be identified that are compatible with both parts being joined. Again, the use of adhesive eliminates the problem.
- Switch to composite materials. Composites are constructed of fibers, such as carbon or glass, embedded in a plastic matrix. They offer superior corrosion resistance, high impact strength and design flexibility. However, the challenge of joining and fastening these materials delayed their entry into the market. Fortunately, fiber-reinforced plastic, sheet-molded composites and other plastics can now be successfully bonded with structural adhesives. Bonding and sealing can be accomplished in a simple, one-step process, requiring little surface preparation.
Adhesives such as LORD® 7800 Fast Cure Urethane Adhesive, LORD® 7542 Urethane Adhesive and LORD® 7545 Urethane Adhesive are already used in some of today’s major automotive OEM panel assemblies. We work with our customers to develop innovative bonding processes that will lighten their load and help improve fuel efficiency.