a bimodal spinneret system including the bimodal spinneret and method for making a surgical buttress having improved characteristics are disclosed . the bimodal spinneret includes at least a distribution of hole diameters to create fibers with a more heterogeneous shear history and die swell . the system and method of using the bimodal spinneret creates a melt blown non - woven fiber mat that is cut into a surgical buttress having unique fabric properties such as differentiated load deflection behavior , flexural stiffness , polymer fiber alignment , fiber crystallinity and subsequent strength retention during in vitro degradation not attainable with unimodal spinneret hole diameters .