Things you need to know about Adhesives and the substrates you're trying to bond.

As one can imagine there are endless applications for adhesives. There are also "traditionalists" in their trades who will never part with what they've always known to be true. In today's world, traditional bonding methods are challenged by new substrate materials, costs of labour, costs of tools and available space in which to produce their finished goods. Newer forms of adhesives offer an alternative to both traditional adhesive methods and mechanical fasteners. The evolution in the manufacturing of trains, planes, buses, furniture and even home construction materials has created a new generation of applications where screws, nuts, bolts, rivets, nail, staples, wood glues and even welding no longer work as well as they once did.

In the development of today's products, manufacturers are seeking to achieve three very basic principles: faster, lighter and stronger. Engineers have struggled to incorporate these three principles into their designs and in many cases they can achieve two of the three principles quite easily, but the third is often elusive or appears costly. With the advancement of technology and the introduction of what was once considered "space-age materials" into our everyday lives, the result is one critical issue for manufacturers to resolve: How do we assemble this?  The most cost-effective method in so many cases is "Adhesives". Not to be confused with your elementary school white glue, wood glues, or even the so-called “super glues” you buy at the hardware store. Today’s industrial adhesives are highly engineered materials and in many cases, most people wouldn't believe where these products are being used today.

One material that has troubled numerous manufacturers, including the furniture industry, is the broad use of MDF (Medium Density Fiberboard). The reality is that these products are essentially wood fibers blended with a bonding agent that once cured, hardens into a formed substrate that looks like wood. One very important aspect which is often overlooked is that a manufacturer might think they're bonding "wood to wood"… but are they?  The truth is, if anything, it's more likely a "plastic to plastic" application. Wood glue, by nature, soaks into the grains of the wood. Once cured, it’s usually very strong. MDF, however, has no grain and so the wood glue can't penetrate the material. It fills the joint but doesn't have a lot of strength. As a result manufacturers turn to mechanical fasteners (nails and staples) which are thought to be better. Why not use a better adhesive?

Cyanoacrylate adhesives, by comparison, have incredible strength and perform best when the bond line is very thin (you could read this as “less is more”). Testing usually results in what we call “substrate failure” (where the adhesive holds and the substrate breaks), not “adhesive failure”. Unfortunately, most people’s preconceived ideas about adhesives get in the way of a perfectly good (and practical) solution.

Similar to the MDF application, we visited a prospective client’s facility and discovered the current supplier had done a really good job of selling their wares (ie not necessarily the best product for the job).  In this situation the manufacturer was bonding a metal product to another substrate. The manufacturer was using a specialized structural adhesive specifically designed to bond raw "metal to metal".  However, it turned out that one of the substrates was a powder-coated metal component, so it wasn't a true "metal to metal" application. It was in fact, a "plastic to plastic" application. As it turned out, we were able to reduce the customer’s input costs by having them use one product for all their applications instead of two or three. Though this isn't typical, we do know users of adhesives who don't always know "why" they’re using them.

Again, it’s important to truly know what you're bonding! Still have questions?  You’re welcome to use our Contact Form and consult with our "Adhesive Systems" factory trained specialist to discuss your needs!

-Peter Atchison, Steeves Agencies Inc