Abstract: The disclosure concerns a technique for forming screen packs which may be used in filtering foreign matter from an extruded plastic material. Such technique involves initially forming a sandwich array which includes a number of sheets of screening, each sheet of screening having a desired orientation with respect to each other sheet of screening. The sandwich array also includes at least one sheet of thermoplastic material. The sandwich array is heated, in order to cause the thermoplastic material to flow into the openings in the sheets of screening, such that the sandwich array will constitute a unitary structure upon the cooling of the thermoplastic material. Thereafter, at least one screen pack, and preferably several screen packs are formed from such unitary structure, e.g., through the performance of a suitable punching operation on the unitary structure.