Those working in our field have heard at least once: “The double-sided tape you sold me does not stick.” Well… maybe more than once.
From our investigation—analyzing complaints and customer reports received over the past year—we discovered that more than 95% of bonding failures, cases where the adhesive didn’t work, were not caused by the product itself but by its misuse.
So, we had the idea of creating a short storytelling series where we share all the horr… ehm… errors… made from time to time by end users. Of course, each mistake will be followed by our tips on how to avoid them.
Chapter 1: The Substrate
Anyone who wants to buy an adhesive—or sell one—should keep in mind the concept of “Surface Energy.”
Simply put, surface energy is a substrate’s ability to create chemical bonds. Adhesives—whether in tape or liquid form—are chemical substances, so here’s the key idea:
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Low-energy surfaces are more difficult to bond.
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High-energy surfaces bond more easily.
But what are considered high-energy and low-energy surfaces?
These:
| Material | Surface energy | Level of surface energy |
| Copper | 1100 | Very high |
| Stainless Steel | 1000 | Very high |
| Raw metal | >500 | Very high |
| Glass ceramic | From 250 to 500 | high |
| Glass | From 200 to 400 | high |
| Concrete | From i 60 to 75 | Medium |
| Nylon | From 43 to 47 | Medium |
| PET (polyethylene terephthalate) | From 43 to 47 | Medium |
| PMMA (polymethylmethacrylate) | From 43 to 47 | Medium |
| PUR (polyurethane) | From 43 to 47 | Medium |
| Wood | From 40 to 50 | Medium |
| PC (polycarbonate) | From 38 to 42 | Medium- low |
| ABS (Acrylonitrile-Butadiene-Styrene) | From 37 to 41 | Medium- low |
| PVC rigid ((polyvinyl chloride) | From 37 to 41 | Medium- low |
| PVC soft ((polyvinyl chloride) | From 36 to 40 | Medium- low |
| Aluminium | From 35 to 45 | Low |
| PS (polystyrene) | From 35 to 39 | Low |
| PVA (polyvinyl acetate) | From 35 to 39 | low |
| EVA (ethylene vinyl acetate) | From 34 to 31 | Very low |
| PE (Polyethylene) | From 29 to 32 | Very low |
| PP (polypropylene.) | From 28 to 32 | Very low |
| Polyvinyl fluoride | From 27 to 29 | Very low |
| PTFE (polytetrafluoroethylene.) | Tra i 16 e i 20 | Very low |
Attention to Surface Compatibility
An adhesive that works well on a material listed lower in the table does not necessarily perform well on those higher up.
Don’t make the mistake of thinking, “If it works on polypropylene, it will be fine on steel too!”
Whenever someone says this, somewhere in the world a double-sided tape technician dies.
Adhesive Properties Beyond Stickiness
Besides adhesion, a tape has many important properties such as:
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Thickness
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Temperature resistance
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Aging resistance
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Elongation
A tape that works well on a tricky plastic at low temperature could be completely unsuitable for a metal that must withstand high temperatures.
Always Specify the Surfaces to Bond
If you don’t feel confident choosing an adhesive or asking for advice, always specify which surfaces you need to bond.
Be detailed! There are many substrates (the table doesn’t even cover all of them), and just as many adhesives designed for all combinations.
When a customer answers “ehm… it looks like plastic” to the question “What do you need to bond?”, a technician dies.
If you can’t identify the material, have it evaluated by the adhesive supplier. Send the sample and ask for advice.
Beware of Treated or Painted Materials
Treated or painted surfaces, especially metals, can be very challenging.
Metals usually bond well, but once powder coated or painted, adhesion can become difficult.
Every time you forget to mention a painted metal surface, a technician dies.
Transparency Is Key
Don’t be mysterious.
Trust the person assisting you. The more information you provide, the better the chances of finding the right product for your needs.
What’s Next?
Now that we know how to recognize surfaces, how do we proceed?
We will discuss this soon in the second chapter of Bonding Failures dedicated to “Cleaning of Substrates.”
BMP Team