Environmental factors include such things as the temperature, humidity and physical abuse to which the adhesive will be exposed. Does it have to function in a freezer, or on a hair dryer? Will it remain working on a product subject to knocks and abrasion, or submersion in water or other liquids?

Special usage factors cover matters like the required ease or difficulty of removal; the necessary staying power (one year? ten?); and the existence of any regulations or standards governing application, something particularly important with medical products. For instance, the adhesive sticking a label to a plastic blood bag must be certified as unable to permeate through the bag to contaminate the contents.

Fundamentally, though, the type of adhesive is determined by the surface upon which it is to be used. Adhesion is the force of attraction between unlike materials, similar to a magnetic force. The strength of attraction is determined by the surface energy of the material – the higher the energy the greater the attraction.*

Surface energy is measured in units of dynes/cm. Knowing that Teflon® has a surface energy of 18 while aluminium’s is 840, for example, you can see why very different adhesives would be needed for labelling the inside and outside of a non-stick fry pan.

Label Innovation has considerable experience in selecting adhesives based on the required application, and works closely with customers to ensure they get the adhesion performance they need. [*Ref.: "Fundamentals of Adhesion", 3M Corp.]

Question #5