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.