ABSTRACT

When pressure-sensitive adhesive is applied to a smooth surface, it sticks immediately. The application pressure can be very slight, not more than the pressure due to the weight of the tape itself. The adhesive is said to “wet” the surface, and, indeed, if the tape is applied to clear glass and one views the attached area through the glass, it is found that in certain areas the adhesive-glass interface looks like a liquid-glass interface. From this one would infer that a pressure-sensitive adhesive, even though it is a soft, highly compliant solid, also has liquidlike characteristics. Some knowledge of the interaction between liquids and solids is beneficial to the understanding of adhesion.