| us just don’t really care how adhesives work. | | | | The Seldom Used Alternatives |
| They work, and that’s all we need to know. | | | | The third and fourth seldom used methods include the |
| Some of us are what you’d call armchair | | | | use of van der Waals forces, and moisture aided |
| scientists, and we read technical manuals full of | | | | diffusion of the adhesive into the surface of
well
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| terminology that reads like a foreign language to the | | | | okay the third and fourth are kind of difficult to explain |
| average Joe. | | | | in layman’s terms, and they’re not very |
| Most of us probably fall somewhere in between. We | | | | common anyways, so let’s just talk about the |
| like to know how stuff works, but we don’t | | | | first two for now. |
| want to attend a university of science. | | | | A Little More on Mechanical Bonding |
| So, for the curious layman, here’s a general | | | | Mechanical adhesion doesn’t strictly happen on |
| description of how industrial adhesives work: | | | | a microscopic scale. Velcro, zippers, pins, staples, |
| Obviously, an adhesive is a compound that will adhere, | | | | safety pins, and buttons are all forms of mechanical |
| bond, or attach two or more items together (or it had | | | | adhesion. Mechanical refers to the fact that it is simply |
| better, if they don’t want us switching brands), | | | | some physical shape holding the two surfaces |
| everybody knows that. It’s the science behind it | | | | together, like a pair of hands clasping tightly. |
| that not everyone is familiar with. Adhesives work in | | | | In glues and adhesives, the mechanical adhesion |
| one of four ways. The most common are mechanical | | | | through the pores of the surfaces occurs thanks to |
| and chemical bonding
| | | | the drying or curing process. When the glue goes on, |
| Mechanical bonding | | | | it’s in a thin, liquid adhesive form, which still allows |
| The simpler and more common form of adhesion. In | | | | either surface to move freely. This liquid form also |
| mechanical bonding, the bond formed between the | | | | allows the adhesive to soak into the pores of the |
| adhesive and the surface occurs when the adhesive | | | | surface. When it begins to dry and become solid, it |
| works its way into the small pores of the surface. It | | | | works, just as Velcro, as just a bunch of hooks holding |
| acts as if millions of microscopic screws and bolts | | | | the two objects together. |
| were driven into both surfaces to hold them together. | | | | One More Thing About Chemical Adhesion |
| Chemical bonding | | | | Chemical adhesion is more complex and only happens |
| Chemical bonding is when an adhesive actually bonds | | | | on a microscopic scale. It works by forming a |
| with the surface on a molecular level. This would be | | | | compound between the chemicals of the two |
| the same thing as what happens when two atoms of | | | | surfaces. The reason this form isn’t quite as |
| Hydrogen bond with one atom of Oxygen, hence, | | | | popular for epoxy adhesive manufacturers should be |
| H2O, or water. Certain chemicals are simply attracted | | | | obvious. Chemical adhesion happens all the time in |
| to each other. Hydrogen especially has a tendency to | | | | nature, but it’s kind of a difficult thing to engineer |
| bond with whatever other atoms it happens to find | | | | at one’s leisure. |
| lying around. | | | | |