Most popular label products are preset with their recommended adhesives, often determined by the label material you select. All our pressure-sensitive adhesion labels are capable of bonding with “high surface energy” (HSE) materials, such as glass, smooth metal, and many common types of plastic. Every once in a while, though, you run across a plastic surface that stickers just won’t stick on. Why is that? Do they have grease on them? Well, unless they are a recently used butter container, the answer is probably no. Some plastics are “nonstick” by their very molecular structure. Think Teflon®.
Teflon® is a plastic surface (polytetrafluoroethylene, to be precise) that can resist heat, but it also has the handy characteristic of not allowing things to stick to it. It’s often applied to cookware. Whether it is overcooked scrambled eggs or an adhesive label, neither is likely to stick well to a smooth Teflon® surface. Plastics like this are known as low surface energy, or LSE plastics. Besides Teflon®, other common LSE plastics are polypropylene and polyethylene.
If you pour a liquid onto a material with a high surface energy, the liquid will not bead up, but rather pool out, smoothly covering the other surface. This is called “wetting out.” An example is rain on an unwaxed car. Pour that same liquid onto a surface with a low surface energy, though, and the liquid will bead up, just like rain on a waxed car.
What Does That Mean for Labels?Think of a pressure-sensitive adhesive as a liquid. If you put it onto a surface with a high surface energy (like glass, porcelain, steel, other metals), it will “wet out” and cover the surface. This provides a strong bond, because the adhesive is able to form links between the underlying surface and the surface of the label, all over the surface of the label.
But if you place that same pressure sensitive adhesive onto a surface that has a low surface energy, the “liquid” adhesive tends to bead up. It will not spread itself out completely to bond to the surface below it, and so the label doesn’t stick as well. That is what happens with an LSE plastic.
Solutions for LSE Plastics
MaverickLabel.com has solutions for this LSE “non-stick” problem. (Be aware, however, that no adhesive will work as well on as LSE plastic as it will on HSE materials.) LSE-rated materials include:
Other LSE Applications
Other posts in the series: Part 1, Adhesives Primer