Welded metal-to-metal bonds incur much higher labor costs than automotive tapes, due to required certifications, training, inspections, and flaws that are hard to detect in QA. Tapes take minimal training to apply and result in more consistent quality with a lower cost of production. Savings also go up as reliance on expensive tools (drills, torque tools, painting equipment) goes down. Pressure-sensitive tapes cut costs because they are simple to apply. They take less production space, too, as you might eliminate separate areas for priming, painting, and curing.

‘Time is money,’ as the axiom goes. The curing time of glues, epoxies, and paints slows down production. So does welding. Pressure-sensitive tapes, by contrast, take no waiting—they adhere immediately. This makes it quicker and easier for workers to use, accelerating line times, and adding value. Faster bonding techniques with lightweight products will also reduce the physical stresses on human laborers, increasing their productivity and precision in the time they are given.

Tesla received some poor press recently when workers reported using electrical tape (in place of more appropriate solutions) to accelerate line speeds and meet deadlines. Consumer-grade tapes like this have no place in automotive assembly, of course. But there’s a lesson here. Pressure-sensitive adhesives do streamline assembly. Automotive-grade PSAs eliminate extra steps and complicated processes, even while outperforming other solutions. As engineer Brian Cox explained to Assembly Magazine, “parts that are bonded together don’t need holes to be drilled or punched, and assemblers don’t need to measure torque or double-check fastening operations.” Tapes can be applied just as rapidly and accurately as rivets or screws, without wasting time creating tapped or pilot holes. Holes also weaken substrates and lack the full-contact bonds of adhesives.

Deloitte has identified “lightweight technology” as one of the main drivers that will shape the future of the automotive value chain to 2025 and beyond. Automotive tapes fit neatly into that future—particularly the double-sided varieties, as noted by Grandview Research. Their 2019 market research report attributes automotive tape growth to “increasing substitution of metal fasteners in automobiles due to increased affinity towards lightweighting.” Marketwatch notes the same trend. The US Department of Energy has found that a 10% decrease in automobile weight can improve fuel economy by 6%-8%. Shifting away from conventional mechanical fasteners cuts down automobile weight, while simultaneously saving energy and maintenance costs.

SAE published an article in Automotive Engineering called “Stuck on Structural Adhesives” that shared this tidbit: “When Toyota’s current 4th-generation Prius migrated to the company’s wide-ranging TNGA platform, its body-in-white moved from 3% high-tensile steel to 19%. Adhesives paired with other advanced joining techniques helped to increase the car’s torsional rigidity by a stomping 60%.” Rigidity is a natural byproduct of adhesives like pressure-sensitive automotive tapes, which bond the full contact surface area between substrates. Fasteners require periodic punctures that compromise both substrate strength and overall vehicle rigidity. The stress concentration of fasteners can even weaken the assembly, causing elements to buckle or tear more easily than tapes that disperse force along the whole bond.

Threaded fasteners have to screw into place. Ergo, they can also unscrew and loosen over time. Nonetheless, the public perception persists that tape is a weaker solution than nuts and bolts. This simply isn’t the case. As Sandy Munro related in the above SAE article, “Anything you can possibly imagine, they glued together. The polyurethanes they are using are unreal.” Modern, permanent adhesives require less maintenance and can easily outlast the vehicle. Adhesion isn’t the only way automotive tapes boost durability, though. Clear protective tapes add longevity to components and thereby add value to the price paid by OEMs.