Patent ID: 6120634
Filing Date: 2000-09-19
Classification: B29C,Y10T

Abstract:
In a process for forming irrigation drip tape, the steps of:a) supplying a longitudinally continuous strip of flexible plastic material in a first direction;b) heating a narrow band of said strip continuously along its length;c) depositing a continuous pre-formed bead of plastic material incorporating a plurality of secondary flow paths on an upper surface of said strip, along said narrow band, while said strip moves in said one direction, wherein said bead is preformed on a form wheel having a peripheral surface with a groove therein shaped to form said plurality of longitudinally spaced secondary flow paths in one surface of said bead, said opposite surface of said bead being substantially smooth, and wherein said bead is deposited on said upper surface of said strip such that said plurality of secondary flow paths face, and are closed by said upper surface of said strip;d) cooling said strip and said bead;e) folding said strip longitudinally so that said longitudinal edges overlap; andf) sealing said longitudinal edges to form a tubular drip tape with a longitudinal, overlapped seam, with said bead located inside said tubular drip tape and extending parallel to but remote from said overlapped seam.