Due to their enormous temperature resistance and optimal stress crack resistance, pipes made of cross-linked polyeth-ylene have established themselves worldwide for heating, district heating and geothermal heating systems, and for hot and cold water transport in buildings. For their cost-efficient production, battenfeld-cincinnati recently demonstrated in Vienna its most powerful PE-Xa extrusion line to 40 customers from Europe and the Near and Middle East. With an output of up to 150 kg/h, it reaches substantially higher throughput rates than conventional lines or RAM extruders and offers the advantage of an extremely short, low-maintenance cross-linking station. In contrast to other pro-duction and cross-linking processes, the inline process demonstrated on this occasion enables the production of peroxide cross-linked pipes with high cross-linking rates at extremely low cost.Prior to demonstrating the line, presentations were held by battenfeld-cincinnati and its partner companies, which were also present with a small exhibition during the line demonstration. The performance of the powerful turnkey extrusion line for producing PE-Xa pipes, as well as the way it was presented, met with a very positive response from the visitors. "PE-Xa pipe extrusion is not an easy task, due to the special demands of the material – so we are all the more pleased that we were able to answer our customers' questions during the presentations and afterwards directly next to the line", Dietmar Stani, Product Manager at battenfeld-cincinnati Austria, sums up with pleasure. "Through intensive testing, we have gathered experience with PE-Xa, which we have subsequently incorporated in the creation of our specialized extruder and pipe die for PE-Xa processing. As a result, we can offer our customers an optimal system for processing this material."
Core components for cross-linked PE pipe production, beside the optimal material blend and the cross-linking unit, are the twin screw extruder and the pipe head.
With its screw geometry specially designed for this application, the counter-rotating parallel extruder model twinEX 93-28 PE-Xa from battenfeld-cincinnati that was presented ensures homogeneous melt processing at low melt temperatures. Thermal stress and flow stagnation are excluded, and a favorable dwell time profile is achieved as well. The same principles apply to the RK32PEX pipe head used in the line. The pipe head has been specially adapted to the task in terms of pipe head volume and streamlined flow chan-nels, in order to prevent material deposits and cross-linking inside the die.
Via an elbow adapter, the pipes pass directly into the infrared ov-en. Eight IR heating elements installed inside the vertical, extremely space-saving oven ensure a high cross-linking rate at line speeds of up to 30 m/min. In combination with the matching downstream equipment for pipe calibration, cooling, haul-off and cutting, an excellent quality standard for the pipes is ensured, which is indispensable for these specific applications.
