Abstract: Methods and apparatus for meltblowing utilize an auxiliary manifold to dispense a fluid between an orifice of a die that is expelling polymeric fibers and an exit of a duct that is dispensing a secondary flow of gas onto the fibers. The fluid dispensed from the auxiliary manifold reduces a recirculation zone of the secondary flow between the exit and the orifice that, absent the fluid from the manifold, results in errant fibers that are blown back into the face of the die by the recirculating secondary flow.

Abstract: Manifolds are designed to deliver fluid through multiple orifices of the manifold such that for a given inlet fluid pressure the fluid being output from the multiple orifices has a desired mass flow profile. The desired mass flow profile includes a desired mass flow rate and a desired direction and distribution of flow in three-dimensional space. The manifold is first modeled as a two-dimensional representation to determine manifold parameters necessary to achieve the desired mass flow profile within the two dimensions. Then, the manifold is modeled as a three-dimensional representation based on the parameters previously determined for the two-dimensional representation to determine manifold parameters of the third dimension that are necessary to achieve the desired mass flow profile within the three dimensions.