May the Force Be with You: The Science of Sticking

Have you ever wondered what makes glue sticky? That stickiness is the result of two physical properties: adhesive and cohesive forces. “Adhesion” is the binding force between two different materials and “cohesion” is the binding force between two similar elements.

So, when it comes to glue’s stickiness, the cohesive force causes the glue to stick to itself, whereas the adhesive force holds the glue to a material. For glue to work, it has to not only stick to the materials you want to hold together, but it has to also adhere to itself. What a brain-buster!

Many people call us to help fix “pop-opens” – when the glue or adhesive they are using fails and the flaps of a box remains open. This happens because the cohesive forces of the glue which should make it stick to itself are weaker than the adhesive force of the glue sticking to the cardboard, causing the box to “pop” open and leave glue residue on both flaps.

Now you know what makes glue sticky! And if you ever have a “glue-mergency” where your adhesive application is not sticking – call us for help with troubleshooting!