Abstract

A process for making low cost drip irrigation lines comprises molding a drip emitter having an elongated labyrinthine channel formed in the depth of the emitter body. Emitters of other configurations also can be used in the process. A plastic film is extruded and passed through a film die with an air injection tube at one end forming a plastic film bubble. At the bottom of the extruded plastic film bubble a pair of pressure rolls join opposite faces of the bubble to form a continuous unitary extruded plastic film sheet. The emitters are moved in series toward the nip of the pressure rolls and are inserted in sequence with their labyrinthine faces facing toward the hot bubble. The emitters are bonded to the extruded film sheet using the heat of extrusion, and the external sheet forms one face of the labyrinthine channel through each emitter. After laminating the emitter to the extruded film, an exit hole is formed through the film to each emitter and the film is then wrapped and bead sealed to form a continuous flexible drip irrigation tube with the emitters spaced apart along the inside of the tube. The process can be used for making multiple drip irrigation lines in parallel along a single extruded plastic film sheet.