Abstract: A procedure and apparatus for testing the hot tack properties of heat sealable flexible packaging materials. A portion of a test strip of heat sealable material is lapped and a segment of this portion heat sealed together. Upon completion of the heat seal the unsealed ends of the test strip are pulled apart at a prescribed constant rate to gradually delaminate the heat seal while the heat seal is cooled at a prescribed rate. Force required to delaminate the seal is continuously recorded as a function of time as the heat seal cools, thus providing data on seal strength for a full range of temperatures of the heat seal as it cools over time. In the apparatus a threading bar intercepts the strip intermediate its ends and pulls a portion through the opening between opposed dies of a heat sealer and in doing so laps the portion of the strip pulled through the opening.

Abstract: A procedure and apparatus for testing the hot tack properties of heat sealable flexible packaging materials. A portion of a test strip of heat sealable material is lapped and a segment of this portion heat sealed together. Upon completion of the heat seal the unsealed ends of the test strip are pulled apart at a prescribed constant rate to gradually delaminate the heat seal while the heat seal is cooled at a prescribed rate. Force required to delaminate the seal is continuously recorded as a function of time as the heat seal cools, thus providing data on seal strength for a full range of temperatures of the heat seal as it cools over time. In the apparatus a threading bar intercepts the strip intermediate its ends and pulls a portion through the opening between opposed dies of a heat sealer and in doing so laps the portion of the strip pulled through the opening.