Abstract
In our earlier report, the mechanical properties of heat-sealed part of poly(lactic acid) (PLA) film showed that optimum heat seal temperature was established to be approximately 130ºC based on the results of peel test, tensile test with circular notch, DSC, FT-IR and MOR measurement.
In this study, we investigated the effect of heat-sealing pressure on mechanical properties and molecular structure at heat-sealed parts of PLA film by using peel test, tensile test with circular notch, SEM, optical microscope, and birefringence measurement. As a result, the peel strength indicated the tendency of increasing with decreasing heat-sealing pressure. That is, the peel strength showed the highest strength at 0.1MPa among conditions (0.1-0.5 MPa). It is clarified that the existence of air hole between PLA films plays an important role to the heat sealing of films.
