A critical parameter in many film applications is seal performance. This can be characterized through
two different methods; ultimate seal strength and hot tack strength. These properties have varying
degrees of importance depending on the application and downstream conversion process. Ultimate seal
strength is measured against ASTM F 88-05 and involves creation of a seal at a given temperature,
pressure and dwell time followed by the measurement of the tensile strength (to initial failure) once the
film has cooled to ambient temperature.