Wide band extruder nozzle

Claim 1

An extruder nozzle for producing a relatively wide flat ribbon of extruded fluid comprising in combination, a fluid supply inlet, a main body portion forming a first side boundary of an elongated channel of constant and generally rectangular cross-section terminating in an orifice, said main body portion having a groove therein, the mean cross sectional area of the groove being substantially greater than the cross-sectional area of the supply line, said groove communicating with said inlet and being substantially arcuate in shape and positioned in said main body portion so that the ends of said groove are closer to the orifice than is the center of said groove, said groove being dimensioned so as to cause a fluid to flow generally uniformly through the entire length of the orifice so as to cause the orifice to fill essentially completely with fluid, a front cover plate for providing a second side boundary of the channel opposite the first side channel boundary formed by said main body portion, and a shim means positioned between said main body portion and said front cover plate to establish the cross sectional area of the channel from which the fluid is extruded, said shim means forming two opposed end boundaries of said channel and dimensioned so that said arcuate groove in said main body portion is terminated at both its ends by said shim means thereby establishing a reservoir of fluid at each end of said arcuate groove to facilitate extruding a ribbon of relatively even thickness from said nozzle.