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.

Abstract: Turbulent-flow emitter channel sections are vacuum-formed in an extruded flat plastic strip. The strip is then applied to a hose substrate, and inlet and outlet openings are formed at opposite ends of the channel sections. The strip may be hot-melt bonded to the substrate during a co-extrusion process, or it may be applied to the hose substrate in a separate operation. Flow rates are easily controlled without changing the structure of the strip by varying the number of channel sections in which outlet openings are formed.

Abstract: An irrigation conduit comprising an extruded tube having a peripheral wall and at least one elongated passage and an elongated supply tube having an elongated supply passage. The supply tube is formed of sheet material joined together along longitudinally extending portions to form a seam. A region of the sheet material extends at least part way around the perimeter of the extruded tube, and the extruded tube is retained on such region of the sheet material. Transfer ports extend between the passages of the two tubes and discharge ports extend from the passage of the extruded tube to the exterior of the irrigation conduit.

Abstract: An irrigation conduit comprising an extruded tube having a peripheral wall and at least one elongated passage and an elongated supply tube having an elongated supply passage. The supply tube is formed of sheet material joined together along longitudinally extending portions to form a seam. A region of the sheet material extends at least part way around the perimeter of the extruded tube, and the extruded tube is retained on such region of the sheet material. Transfer ports extend between the passages of the two tubes and discharge ports extend from the passage of the extruded tube to the exterior of the irrigation conduit.