Adhesive bonding is growing in popularity as a way of mating metallic substrates without mechanical fastening in the automotive and aviation industries, as examples.
In the video above, we talk about how adhesive bonding has begun to rival and exceed the performance of mechanical fastening with John Hill, principal scientist for structural adhesives for Lord Corporation.
“Acrylic adhesives have several advantages over mechanical fastening,” said Hill.
“The first one I can think of is cosmetic. Using adhesives, you don’t have any rivets or welding that shows on the surface. Another advantage is distribution of stress. For crash toughening, especially as you’re getting into thinner and thinner substrates, you’ve got localized stresses at weld and rivet points. With adhesives, you can distribute that stress over the entire surface area of the bond.”
Adhesive bonding’s greater distribution of stress creates a tougher and more failure-resistant surface compared to welding and riveting. This strength is tested traditionally, by pulling apart the bonded substrates.
New technologies are also being developed for non-destructive testing, primarily using sound and other resonance waves to determine gaps in bonding, Hill explained.
“One of the key advantages of acrylic adhesives is the usability and user friendliness of acrylic adhesives, urethane and epoxy adhesives, especially in metal bonding, for example,” Hill said.
“Acrylics are well known to bond through even oily and dirty metal surfaces, so you need only a minimum of surface preparation. In fact, we have some customers who have no surface preparation, where the acrylic adhesive will bond through the cutting oils and still provide excellent bonding between the surfaces.”
Acrylic adhesives also feature a cure-on-command capability and can be tuned to give a longer open time.
“Acrylic adhesives are, I think, the best you’re going to get,” said Hill.
For more information about acrylic adhesives, watch the video above and visit the Lord Corporation website.