ABSTRACT
“Pressure-sensitive adhesive” (PSA), when in a dry state, will adhere to a variety of surfaces merely by application of light hand pressure. Pressure-sensitive adhesives were first developed in the mid-1800s for use on surgical tapes. Their use has since expanded to include masking tapes for spray painting of automobiles, as well as a myriad of other uses in the consumer-tape and graphic-arts fields. Pressure-sensitive adhesives are usually identified by the chemical nature of the elastomer [e.g., natural rubber, styrene-butadiene rubber, acrylic, etc.]. Hot-melt pressure-sensitive adhesives, which were introduced during the 1970s, are now being used successfully by a variety of industries in, for example, floor tiles, labels, and tapes. Pressure-sensitive adhesives are gaining increasingly wide acceptance by the label industry at the expense of wet adhesives, pregummed remoistenable adhesives, and heat-activated adhesives.
