Just glue it?
Just repair the broken cup, glue the sole of a shoe or seal a pipe? With a little glue, things like that can be fixed quickly, right? Unfortunately, it’s not that simple. In order for the bond to last long and correctly, the surfaces to be bonded must first be properly prepared. You can find out exactly what that means here.
The quality of a bond depends not only on the internal stability of the glue, but also very much on the adhesion between the surface and the adhesive layer. No matter how well the adhesive is suitable for the application – if the surface is not pre-treated properly, there will be no optimal adhesion. Several factors play a role in achieving them.
Clean surfaces
It is not just for fun that almost every adhesive label says “clean and degrease surfaces prior to adhesion”. Because dirt and dust as well as grease, oils and silicone sprays are among the greatest enemies of bonding. Every contamination acts like a separating film between the surface and the adhesive and thus has a negative influence on the quality of the adhesion.There are numerous sprays available for surface cleaning. Depending on how sensitive the surface is or how coarse the dirt is, either a gentle or a powerful cleaner is required. The Münster-based manufacturer of adhesives and sealants, WEICON, offers the right product for every application.
This includes, for example, the WEICON Surface Cleaner – the classic for the pretreatment of adhesive surfaces. But the WEICON Spray Cleaner S is also versatile. Thanks to its alcohol-acetone-gasoline mixture, it is particularly powerful and is good for stubborn dirt. If, on the other hand, you need a gentle product, WEICON Industrial Cleaner is a good choice. The spray is even suitable for sensitive surfaces such as rubber materials.
By the way: With the WEICON cleaning – the six-pack of a different kind – you cover a large part of the need for various cleaning products. The set includes the following sprays:
- Surface cleaner
- Electric cleaner
- Industrial cleaner
- Multi-foam
- Citrus cleaner
- Stainless steel care spray
Roughen surfaces
Gluing enables countless materials to be joined together or with one another. This versatility is one of the main reasons why joining technology is such an attractive alternative to welding, riveting and the like today.But as different as the materials, as different as the surface structures. And that can be a challenge when gluing. Rough surfaces are ideally suited for bonding. Because the materials interlock to a certain extent and thus form a stable connection. Smooth surfaces, on the other hand, do not offer the best conditions when it comes to gluing. Here it can help to roughen the surface beforehand. Pre-treating the smooth material with sandpaper, wire brush or – on a grand scale – sandblasting can work wonders.
Primer
It is not always possible to roughen the surface, for example if the material to be bonded is to be protected. Does that mean “bad luck” in this case, the smooth surfaces cannot be glued? Then plastics such as polyethylene or polypropylene would have a hard time in the world of adhesives. Fortunately, there is also a solution for such materials – in the form of so-called adhesion promoters, also known as primers. A primer works like an adapter. It ensures better wettability of the surfaces and enables chemical reactions between adhesive and material.
And so it goes on
Forgot to clean, surfaces not roughened, no primer used? No wonder the glue doesn’t hold up. Another reason for poor adhesion can also be the wrong choice of adhesive. Although the advertising world leads us to believe that the famous all-purpose adhesive is – there is no such thing as an adhesive that bonds any material under any condition. In the next part of the series “The World of Gluing” we dedicate ourselves to exactly this topic – namely the fairy tale of the all-purpose glue.
Images: WEICON
