In this work, effects of sealing temperature, time, pressure, as well as sealant thickness and viscosity on squeeze out flow (SOF) in heat sealing were examined. A new image analysis approach is presented to quantify SOF in heat sealing. It was found that increasing temperature or pressure could improve SOF but only in thick 130 mu m sealants and reducing the sealant thickness to 50 mu m suppressed SOF. Reducing viscosity in 50 mu m sealant films was also found to improve SOF only at high-sealing pressure and long sealing times. Three approaches were used to model SOF: analytical one-dimensional model, numerical one-dimensional model using finite difference method (FDM), (iii) Numerical two-dimensional model using finite element analysis. Heat transfer was modeled, and it was shown that heat transfer induces a delay in SOF. When the FDM and the heat transfer models were combined, a good agreement between experimental and model prediction could be obtained. In addition, modeling results showed that SOF occurred in shear rates within the transition region between the Newtonian and Power-law regions. This indicates the importance of considering the Carreau-Yasuda fluid behavior in modeling of SOF.
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