The effect of heat sealing temperature on the properties of OPP/CPP heat seal. I. Mechanical properties

Abstract

ABSTRACT:The effect of heat sealing temperature on the mechanical properties and morphology of OPP/CPP laminate films was investigated. The laminated films were placed in an impulse type heat sealing machine with both CPP sides facing each other. The temperatures investigated ranged from 100 to 250°C. T-peel and tensile tests in combination with SEM were used to characterize the heat seals. A minimum seal initiation temperature of 120°C was identified for OPP/CPP laminate heat sealing. Peel strength increased sharply from zero at 110°C to maximum at 120°C, after which a gradual decrease was observed. Tensile strength initially increased until 120°C, after which it gradually decreased until 170°C and assumed a constant value beyond that. The initial rise has been associated to cold crystallization, while the reduction between 120°C and 170°C was due to relaxation in molecular orientation. Beyond 170°C, all the orientation in the laminate has been lost so orientation effects are nullified. Morphological studies with SEM revealed that seals were partially formed at lower temperatures, while the laminates were totally fused together at high temperatures, with intermediate tempera-

Effect of bar sealing parameters on OPP/MCPP heat seal strength

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“…Then adhesion is promoted by applying heat and pressure from the outside of films. The important factors to obtain great heat seal properties by controlling heat seal temperature, pressure, heat seal time and dwell time for a cool down after heat sealing [3][4][5]. The conditions of heat sealed are important for controlling peel strength and heat sealed properties of the films.…”