Designing a plastic adhesive is a considerable challenge given the diverse range of properties that plastic materials encompass. Plastics can be engineered to incorporate any property desired, including hardness, optical clarity, and resistance to solvents and heat. Bonding plastics can be difficult and depends on interactions occurring at the substrate/adhesive interface. Specifically, adhesion requires choosing an adhesive with high cohesive strength and a surface tension lower than the surface energy of the substrate. In response to this challenge, MG Chemicals has developed an epoxy structural adhesive that effectively adheres to most commonly used plastics.
One of our customers needed a strong adhesive for plastic to bond a panel for a bus sign composed of Acrylonitrile Butadiene Styrene (ABS) and Polycarbonate (PC). The new model signs would be exposed to temperatures ranging from -40°C to 80°C. Additionally, the consistency of the adhesive was critical as it had to be flowable enough to conform to a small gap in the back panel, yet viscous enough that it would not flow inside the panel. Lastly, packaging that would facilitate high throughput and ease-of-use was critical.
Key Customer Requirements
- Adhesion to ABS/PC plastic blend
- Ability to operate between temperatures of -40°C to 80°C
- Conform to small gaps
- Should not flow inside the sign
- Resistance to vibrations
- Should match the color of the back panel
- Robust packaging for in-line application
The 9200 2 part structural adhesive is known for its superior adhesion to both ABS and polycarbonate and had no issues bonding those materials. This 2 part epoxy glue was customized for this particular application by adding black colorant to match the back panel of the sign. MG Chemicals was also able to package this product in a 400mL dual cartridge fitted with a static mixing tip so the product could be easily dispensed, eliminating the need to measure and mix the material by hand. Thermal cycle testing was carried out by the technical team at MG by cycling the cured part from -40°C to 100°C six times, with no loss of adhesion.
Structural epoxy adhesives such as MG’s 9200 show exceptional adhesive capabilities when plastics must be exposed to extreme temperature ranges. The current 9200 formula can be customized to meet various requirements, including color matching and packaging, which afforded our customer a turnkey solution.