Sintered powdered metal filter

Claim 2

The filter structure of claim 1 wherein said plurality of protuberances comprises from seven to 100 protuberances.

Claim 3

The filter structure of claim 1 wherein the total surface area of the outer surface of said protuberances and the exposed surface of said one major surface is at least three times the area enclosed by the circumference of said base.

Claim 4

The filter according to claim 1 wherein said powdered metal comprises stainless steel.

Claim 5

A unitary uniformly porous filter structure useful for high-pressure filtering of molten fiber-forming thermoplastic resin, said filter structure consisting essentially of shaped sintered powdered metal and comprising a planar base portion having a circumference enclosing a cross-sectional area of at least 2.5 square inches, said area being greater than one inch in minimum dimension, said base portion having through the major surfaces thereof a plurality of perforations and having extending from one of said major surfaces a corresponding plurality of erect elongate hollow protuberances with their cavities in alignment with said perforations, said base and said protuberances each having continuity and identity of composition, said protuberances each having a circumference enclosing a cross-sectional area of less than one-half square inch and the area being less than three-fourths inch in maximum dimensions and having a protuberance wall thickness of at least one-sixteenth inch, whereby is provided a filter structure having protuberances capable of withstanding crushing under application of high pressure.

Claim 6

A spinnerette head assembly for the extrusion of synthetic polymer fibers including tubular housing closed on the end providing a liquid-tight filter chamber, one of said closed ends having an inlet opening and the other having extrusion orifices wherein the improvement comprises interposing within said chamber between said first closed end and saiD second closed end the filter structure of claim 6.