Extruded swell behavior of polypropylene specialized for manufacture of meltblown nonwoven fabric

The effects of temperature,length/diameter ratio,shear rate and melt flow index(MFI) on the die swell behavior of polypropylene(PP) specialized for meltblown nonwoven fabric were investigated using a capillary rheometer to provide the optimal processing parameters to prepare meltblown nonwovens.As a result,the die swell behavior of PP is dependent on various factors.Such methods as using high-MFI PP,improving the process temperature,enlarging the length/diameter ratio and optimizing the inlet angle of the orifice can be taken to diminish the die swell behavior of PP and decrease the folding and diameter of the fibers.