Leading German extrusion machinery producer Reifenhäuser (D-52839 Troisdorf; www.reifenhauser.com) has joined forces with Pipelife International (A-2351 Wr. Neudorf; www.pipelife.com) for the construction of an extrusion unit producing large HDPE pipes with a diameter of up to 2,000 mm. These mammoth dimensions take HDPE pipes into the domain previously occupied by concrete and steel. The extrusion of these giant pipes requires high melting efficiency, good homogenisation of the starting material and a high output rate at a low melt temperature.

3-D illustration of the special die for large HDPE pipes with a
diameter of up to 2,000 mm. (Illustration by Reifenhäuser)

The die is a special construction with melt conduction by means of a spiral mandrel distributor utilising the companies´ expertise in the construction of large dies for sheet extrusion. Both the die geometry and the coating of the melt flow surface need to be adapted to suit low temperatures. The dimensions are variable for diameters starting at 1,600 mm up to 2,000 mm and a wall thickness of up to 135 mm. The total weight of the pipe head with a diameter of 2.60 m and a length of 2 m will be about 50 t.

Coming soon: Giant pipes with a
diameter of 2,000 mm on their way
to their place of installation
(Photo by Pipelife)

The complete extrusion line is planned to start production in June 2004 at Pipelife´s Norwegian site at Stathelle. Here the joint venture between Wienerberger (A-1100 Wien; www.wienerberger.com) and Solvay (B-1050 Brussels; www.solvay.com) already produces what are already the world´s largest PE pipes with a diameter of 1,600 mm. The giant pipes are installed under the ocean floor for applications such as sewer drainage.