Selection of technological parameters for the polypropylene film impulse sealing process based on seal strength

This study investigates the influence of technological parameters on the strength of polypropylene (PP) film seals used in industrial packaging applications. The effects of sealing temperature, sealing time, and jaw clamping pressure on seal strength were analyzed using a five-level response surface experimental design supported by finite element simulations and regression-based optimization. A polynomial regression model with a coefficient of determination of R² = 0.9203 was developed to predict seal strength. The results demonstrated that sealing temperature and sealing time were the dominant process parameters affecting joint strength, while jaw pressure had a comparatively minor influence within the investigated range. No effective seal formation was observed below approximately 100 °C. The optimal process parameters were identified as T = 141.14 °C, t = 2.14 s, and p = 4.65 bar, resulting in an experimentally verified maximum joint strength of Fmax = 33.7 ± 0.4 N. The proposed experimental-numerical methodology can support the optimization of industrial PP film sealing processes and facilitate the selection of process parameters for similar packaging applications.