Abstract

A low cost drip irrigation line is made by molding a drip emitter having an elongated labyrinthine channel formed in the depth of the emitter body. A plastic film is extruded and passed through a film die with an air injection tube at one end forming a plastic film bubble. A feed tube sequentially feeds the emitters in series through the plastic film bubble and to the nip of laminating rolls for laminating the emitter to the plastic film bubble so that opposite wall portions of the plastic film are bonded to the opposite outer faces of the emitter. This encloses the labyrinthine channel and thereby forms a sealed labyrinthine passage. Inlet and outlet openings are formed at opposite ends of the labyrinth and the film bubble, following the laminating step, is formed into an elongated flexible drip irrigation conduit with the emitter on the inside of the conduit so the inlet receives water under pressure travelling in the conduit, passes it through the labyrinthine passage, and discharges the water to the exterior of the conduit at a drip rate. The emitter body can be made from an injection-molded polymer, such as polyethylene, which can contain trifluralin, for inhibiting root growth near the emitters during use of the drip irrigation line.