In cooperation with the American company Drip Research Technology Services USA Ltd., San Diego, California, the Vienna machine manufacturer Cincinnati Extrusion GmbH has developed a new process for continuous production of irrigation pipes. The line concept, a simple, cost-efficient alternative to conventional processes, is of special interest to all markets with a constantly rising demand for irrigation systems. Besides North and South America, this includes Southern Europe, the Middle East, and China.
The development of this new extrusion line concept started with the idea of replacing the so-called “drippers“ placed on the inside of conventional irrigation pipes with a continuous, embossed PE tape. So far, the injection-molded drippers have always been inserted in the course of pipe extrusion, and driven into the pipe just after extrusion through the rear of a crosshead at pre-set intervals. Mechanical insertion of these components requires a sophisticated, high-precision mechanical system. Then, at the end of the pipe extrusion line, a hole is punched into the pipe at the exact spot where the dripper has been fixed.
In new irrigation pipes this dripper is now being replaced by an embossed PE tape with a special kind of embossing that takes over the task of pressure control and ensures that a stable irrigation performance with precise metering of the amount of irrigation water required is maintained. The embossing, and thus the performance of the irrigation system, can be adjusted by simply exchanging the embossing module in the production line.
How the DRIP TAPE LINE works
The complete production line for irrigation pipes with a PE tape inside performs two production steps: first manufacturing of the tape and then pipe extrusion with simultaneous insertion of the tape into the pipe.
The PE tape is extruded with an Alpha 45 single screw extruder and a special die, then embossed directly by a down-stream embossing unit, ready for insertion into the crosshead of a second extruder by means of a special feeding unit. The actual pipe with a 20 mm external diameter and 0.15 to 0.2 mm wall thickness is manufactured on a Proton 60 single screw extruder. Through the specially designed crosshead the tape is fed into the interior of the pipe and then directly welded on in the calibration unit. Next, the pipe is cooled in a full bath cooling aggregate laid out for high-speed extrusion. Then, in the haul-off unit, the holes to release the water are punched into the pipe at precisely defined spots. Finally, the pipe is wound up on an automatic winder.
The advantages of this process are obvious:
• a simple process
• simple operation, since this is a continuous process
• high extrusion speed of up to 100 m/min
• flexible adjustment of the embossed tape to the irrigation performance needed through simply exchanging the embossing module
• generally higher cost-efficiency compared to conventional, intermittent processes.
In May of this year, Cincinnati Extrusion presented this innovative line concept to a gathering of several customers. In view of the very positive response, the machine manufacturer is planning to stage another demonstration in its Vienna technical lab towards the end of September.
