Testing pressure-sensitive adhesives under standard conditions of temperature and relative humidity is always a preferred means to compare data from lab to lab and from lot to lot, but it is sometimes necessary to evaluate the performance of an adhesive under conditions that it would encounter in the field.
September 11, 2000
Many adhesives exhibit different properties when subjected to variations in temperature. Some of these adhesives are thermoplastic. They soften when heated and become more brittle when cooled. [In the case of pressure-sensitive adhesives (PSAs), the nature of the bond is nearly always thermoplastic.] If for the sake of this discussion we limit our testing to tack, peel and shear, we can develop a series of observations that can be applied to most testing situations.