As the old saying goes, there is “more than one way to skin a cat”… and, if you work in a product development or manufacturing business, you will know that there is more than one way to join things together.
In this article we will see how the Surface Energy of materials can affect an adhesive bond. We will also explore some of the adhesive properties you should consider when sticking two surfaces together.
Unlike the poor old cat, in the manufacturing world, we need to ask questions about what we are trying to achieve. What materials are we using, why we are using them and what sort of properties should the join have?
Why Use Adhesives?
We can of course go for a mechanical type solution. That could be a screw or a bolt, a bracket or a clamp style compression fixing. Depending on what you are trying to achieve any of these methods, or a combination of them, might be absolutely fine.
However, in the sleek, modern, high-tech, apple computer, handheld device type world of today, we often need joins to be a little more “discreet”. In these cases adhesives can provide the ideal solution.
With a huge choice of adhesives tapes and films to choose from, which adhesives are right for your application? This again comes down to asking the right questions and knowing what you are trying to achieve.
One of the key factors to consider is the “Surface Energy” of the materials you are attempting to join. So, what is Surface Energy?, and how does it affect your application?
While you may not have ever heard of Surface Energy, I’m sure you will have seen its effects. Surface Energy refers to the properties of a material and how easily liquids (including adhesives) can spread out over the surface.
Imagine a freshly washed car. Water splashed onto the paintwork spreads easily leaving the surface “wetted”. After an application of a wax finish to make it shine, water will “bead” and run off the paintwork leaving very little residue left behind. In this case the painted surfaces have a higher surface energy that those panels that have had the wax applied.
In terms of adhesives, if a material has low surface energy, it will tend towards non-stick properties. This can make it more difficult for the adhesive to work effectively. A stronger adhesive or a thicker covering may be required. In some cases even a completely different (LSE) chemical formulation could be required, that will work with your chosen materials. .
Flexibility and Permanence
Aside from the materials themselves, some of the other properties to consider could include flexibility and the level of permanence required. Flexibility would enable a bond to move a fractional amount perhaps to withstand vibrations during normal use, without the bond failing and a permanence level that could allow for a part to be fitted and re-positioned several times before the adhesive is cured sufficiently for a permanent fixed position.
Just think about those office notes you get stuck to your screen when someone leaves you a message. You can move these around and stick them to all sorts of surfaces, multiple times, before the adhesive loses its stickiness. Originally developed by 3M, the Post-it-Note revolutionised “leaving a note” for someone.
In many manufactured components, another factor to consider is the heat resistance properties of any adhesive used. If adhesive is in close proximity to heat sources such as lights or electrical components, this may cause it to soften. Similarly if equipment has to operate in low temperature conditions, this may cause adhesives to become brittle. In either case you would not want the adhesive to fail.
Not only is it important that the adhesive remains effective, but the materials you are joining will also need be resistant to extremes of temperature.
Whether you are making nameplates, membrane switches, displays or securing automotive parts, Cadillac Plastic has a wide range of adhesive films in stock, designed to tackle these and other requirements.
With tapes and films from major manufacturers, including 3M, Avery, Nitto and Flexcon, we are sure to have the right adhesive for your application.