Abstract: A method for the continuous production of finely ground particulates coated with a barrier, or other desirable film wherein the coated particulates exhibit a diameter of less than 10 microns. In an exemplary embodiment, large coated particulates are introduced into a fluid energy, or jet mill, along with smaller, uncoated particulates. As the particulates collide within the mill they are comminuted, and an amount of coating is transferred from the coated particulates to the uncoated ones such that they become sufficiently coated and size-reduced to a desired size. Alternatively, uncoated particulates are milled and coated during their milling. Still alternatively, uncoated particulates are milled and subsequently directed through an atomized mist of coating material wherein the size of the mist droplets are as large, or larger than the directed particulates.

Abstract: Melt fracture is reduced, without the necessity of polymer processing-aid additives specifically designed to alleviate exit region surface melt fracture phenomenon, by heating at least a portion of the die through which the polymer is extruded. The die exit region is maintained at a temperature above the bulk melt temperature of the polymer extruded through the die exit hole.