The use of adhesives is growing rapidly in manufacturing in practically all industries. The advantages of using adhesives are clear: they are lightweight, clean, safe and cost effective. This means more and more design engineers are in the process of selecting a Pressure Sensitive Adhesive for their application. An impetrative part of the adhesive selection process is to determine the surface energy of the two substrates that are being bonded.
WHAT IS SURFACE ENERGY?It is the measure of how well an adhesive “wets out” over the surface. In other words, how well the adhesive sticks. Low Surface Energy (LSE) substrates do now allow adhesives to wet out, making them difficult for adhesive to adhere. Some LSE substrates include: Polystyrene, Acetal, Polyethylene, Polypropylene, Teflon and powder coated paints. High Surface Energy (HSE) substrates allow for adhesive wet out, making them easy for adhesive to bond. Some HSE substrates include: Metal, Kapton, Polyester, Polycarbonate, Acrylic and ABS.
Surface condition can also be a factor in determining the surface energy of a substrate. Is the surface rough, smooth, porous, coated, uncoated, clean, flexible, etc.?
Certain adhesives will provide better adhesion to LSE substrates while others are better suited for HSE substrates.
Understanding surface energy is one of a few important factors to consider when selecting a Pressure Sensitive Adhesive for your bonding application. For a comprehensive guide, check out our free download “4 Questions to ask when choosing a PSA”