Experimental and statistical analysis of the effects of the processing parameters on the seal strength of heat sealed, biaxially oriented polypropylene film for flexible food packaging applications

Seal strength is an important quality parameter for packaged products such as biaxially oriented polypropylene films. The seal quality can be insured and maintained under optimum heat sealing process parameters. This article shows that heat seal strength can be optimized through simultaneous study of dwell time, pressure, and temperature. The heat seal strength optimization trial for 18 µm thick untreated, both sides sealable biaxially oriented polypropylene film utilized response surface methods with a replicated central composite statistical experimental design. This gives a second-order model for heat seal strength. This experiment showed that dwell time, temperature, and their interaction have significant effects and that high seal strength is attained at a dwell time of 0.9 s and temperature 120°C.