Apr 28, 2022

Bonding Agents for Transportation Industry Components: Balancing Safe, Sustainable Materials with Performance Needs

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Environmental consciousness is increasing the demand for electronic vehicle sales, and Gartner now predicts 6 million will be shipped this year, up from 2 million last year. That’s great for auto and aircraft manufacturers. However, corporate sustainability goals are also forcing these companies to rethink the way they make these vehicles, particularly the parts and components used. The auto parts themselves are often made from materials that are not environmentally friendly, so suppliers are working to develop and implement greener alternatives.

For example, consider rubber parts and components that are used to decrease noise and vibration in transportation vehicles. These parts are often made from rubber bonded to metals like steel, aluminum, zinc, copper or plastic substrates like polyamides, polyacetals, polyesters and PTFE. Components used in the transportation industry must be able to withstand harsh environments and high pressures for many years, so robust adhesives are required to ensure a strong bond. Until recently, rubber-to-substrate bonding (RTSB) adhesives were made with chemical solvents, which threaten both workers and the environment.

Risks associated with Organic Solvents

Solvents are volatile organic compounds (VOCs), and occupational exposure occurs by skin contact or inhaling the solvent vapors. They can affect the central nervous system and cause headaches, dizziness, and light‐headedness progressing to unconsciousness, seizures, and death.

Organic solvents are also considered an environmental hazard. They react in the atmosphere in sunlight, producing an air pollutant known as “ground-level ozone.” High concentrations of ground-level ozone seriously affect human, animal and plant health and harm building materials, forests and crops.

Because of these hazards, additional costs are involved to dispose of solvents properly. For example, regulations require that an adhesive with 50-95% organic solvent content be incinerated after being applied and dried. These processes emit several VOCs in addition to carbon dioxide.

All of these factors have pushed suppliers to develop greener RTSB bonding adhesives for automotive parts.

Environmental Advantages of Waterborne Bonding Adhesives

DuPont has created several waterborne bonding adhesives that don’t contain VOCs. These adhesives are formulated with natural and synthetic polymers that are designed to be added to water. Polymer chains in droplets called ‘micelles’ are stabilized and dispersed in water. Waterborne adhesives harden when water evaporates or is absorbed into the porous substrate.

MEGUM W-Series and ROBOND grades are proven to effectively bond many different materials without sacrificing performance. They can be used in a wide range of applications and substrates. They also dry 2-4 times faster than solvent-based adhesives, which decreases processing and worker exposure time.

These waterborne adhesives are increasingly being used in the transportation industry. Dupont waterborne adhesives are designed to last at least 15 years, which matches a typical vehicles’ lifespan.

Transportation industry applications of waterborne adhesives:

• Vibration control elements such as springs, bumpers, bushings, suspension systems, clutch mounts, flexible couplings and engine mounts
• Corded-rubber belts and hoses
• Seals and gaskets
• Bearing elements for bridges
• Rollers
• Solid rubber tires
• Track pads for caterpillar vehicles, linings and protective coverings
• Metal-supported profiles

Processing advantages of waterborne adhesives

DuPont waterborne adhesives can be used in existing production lines, so there is no need to purchase new machinery. In addition, machinery is not required to safely dispose of VOCs. For example, switching from solvent-based systems to the MEGUM W-series eliminates the need for incinerators.

Waterborne adhesives also require fewer processing steps than conventional solvent-based bonding agents, reducing overall energy consumption. Additionally, they dry 2-4 times faster than the solvent-based adhesives, which further cuts production process time.

Waterborne adhesives can help reduce your carbon footprint, improve cost efficiencies and increase worker safety without sacrificing performance. To learn more, contact a representative at H.M Royal.