HOT TACK TESTING: A REVIEW

Hot tack is a primary function of flexible packaging. It has taken on more emphasis with the development of sealant copolymers and ionomers as well as the development of coextrusion to meet the packaging industry’s need for heat seal reliability when running at high speeds with more demanding configurations. As with many new terms, “hot tack” has not been precisely defined as yet. This paper, however, will discuss two important aspects of hot tack testing: the multilayered structure with a “hot tack” sealant and methods for relating test results to actual packaging machine performance, with major emphasis on two popular test methods–the automatic test equipment and the spring test.