Patent ID: 6497508
Filing Date: 2002-12-24
Classification: B29B,B29C

Abstract:
A screw of a plasticating device of the type having an axial length wherein particles of resinous material are introduced upstream through an inlet of a heated barrel having an inner-wall and advanced downstream towards an outlet, the screw comprising:a helical flight to be disposed within and cooperate with the inner-wall of the heated barrel; a cylindrical portion having a continuous helical channel with a depth, the helical channel traversing the axial length in a reverse helical direction as compared with the helical direction of said flight; input grooves extending in the surface of the cylindrical portion with each input groove having an opening beginning in the helical channel and terminating in a dead end before intersecting the helical channel upstream from the input groove opening; output grooves extending in the surface of the cylindrical portion with each output groove being adjacent to at least one of the input grooves, each output groove having an opening beginning in the helical channel and terminating in a dead end before intersecting the helical channel downstream from the output groove opening; a barrier passing between adjacent input and output grooves to form paired grooves and to prevent the grooves from directly communicating with one another; and an intermittent flight that passes between adjacent paired grooves and substantially parallel with the helical channel.