New Automotive “Connector” Technology

July 30, 2017 by Paul Shepard

“Consumer preference for collision protection technologies is paving the way for autonomous driving,” says a study by JD Power and Associates.

Electronics for collision protection, blind-spot detection, night vision systems, GPS navigation, cameras, on-board computer interfaces, wiring, harnesses, screens, entertainment, wireless connectivity, phones, turn-around seats, and driving assistance modules—are adding significant weight to a vehicle and reducing fuel efficiency and, therefore, driving range.

These safety enhancements and entertainment add-ons are even more important to the autonomous driving cars of the future, and there’s an inherent challenge between adding features and maintaining a car’s energy efficiency. “Get more stuff, do more stuff, but we want great mileage too,” seems to be today’s global automaker’s tri-lemma.

Autonomous vehicles need a “weight-control plan.” Consumers want advanced technologies, and they want long driving ranges between electric charging. Lower weight can give us longer driving ranges; but if we add weight in one area, where do we remove weight to ‘make room’ for safety and autonomous add-ons?

Plastics makers are presenting new solutions. Today, at the Management Briefing Seminars, a premiere gathering of auto industry executives, in Traverse City, MI, (1–4 PM), Sandra McClelland, automotive business development manager, Solvay Specialty Polymers USA and presenting chair, American Chemistry Council (ACC) Auto Team, describes the latest discoveries in multi-material reversible bonding, in collaboration with Michigan State University’s (MSU) Composite Vehicle Research Center (Dr. Mahmoodul Haq).

Connectors are used to hold automotive pieces together. Traditional nuts, bolts, clips, clamps, and snaps serve an important function, but can be heavy, costly and time-intensive on an auto assembly production line.

ACC is seeking to reduce those parts, costs, and assembly times, while reducing the weight. Moreover, the industry goal is an alternative automotive adhesive connector that does several important things:

  • Works with “multi-materials” (plastics, steel, aluminum, and polymer composites),
  • Reduces weight,
  • Binds as strongly as other connectors do (ASTM testing for structural efficiency),
  • Applies and adheres in 45 seconds, and
  • Is reversible. The bond can come apart and be “re-joinable” in a local mechanical repair shop or at end-of-life for potential recycling.

Reversible bonding technology developed through collaboration between ACC and MSU not only appears to satisfy these criteria, but provides other distinct advantages.

A connector bolt, clip or clamp, for instance, tightens at a specific spot on a layer (stress point). Our reversible bonding grips the entire seam of a joint (not just one spot). The two layers can become one object. Spreading stress has advantages: It makes considerably stronger joins, which enables additional weight savings because parts joined can be thinner and lighter.

That is not all. Research is now demonstrating this new reversible glue actually gets stronger after use and repair/rebonding. Research overview:

  • First, researchers apply warm glue, bonding multi-materials quickly.
  • Second, they test the joints to failure and record structural efficiencies by stringent ASTM standards for joint fatigue, strength, shear, impact, flex, creep, and modulus.
  • Third, researchers use electromagnetics to re-melt the adhesive in 30 seconds and establish a new “healed” bond to run parallel duplicate tests. The data shows this new bond is actually stronger.

“This is news for carmakers and buyers who want more features plus fuel efficiency. Reversible bonding can enable weight savings, which in turn makes lots of “room” on the weight scale for new components and consumer demands, necessary for autonomous vehicles. Finally, the bond even gets stronger after repairing and rebonding, an amazing phenomenon for any automotive material,” said Ms. McClelland.