KraussMaffei Berstorff: More time for big foam tubes

The new KraussMaffei Berstorff paternoster system offers a cost-effective alternative to conventional cooling systems, providing an up to tenfold increase in the cooling time of PE insulation foam tubes. The space-saving paternoster system is now available for ISO-TUBE Schaumex and Schaumtandex lines.

Challenging residual heat removal
PE insulation foam tubes produced on high-performance foam extrusion lines generally require sufficient cooling time prior to packaging. With conventional foam tube extrusion processes based on physical foaming, the products are cut to a length of 2 meters at the end of the cooling section and directly discharged into boxes provided for this purpose. Depending on the tube diameter and wall thickness, the material still exhibits substantial residual heat with this cooling method. Even when appropriate reversing systems are used to return the foam tube to the extruder in order to pass the cooling section once again, a maximum threefold increase in the cooling time can be achieved. A further extension of the cooling section is often limited by the available floor space.

Longer cooling time
The newly developed KraussMaffei Berstorff paternoster solution is equipped with a circulating chain system including 126 transport trays. The precut foam tubes with minor excess length are automatically placed in the trays and discharged after having passed the paternoster system. A total of 104 trays are filled with tubes, which corresponds to a cooling section length of over 200 meters. “Based on a typical production speed of 20 m/min, the residence time in the paternoster is about 10 minutes,” explains Matthias Reimker, product manager for foam tube lines at KraussMaffei Berstorff. “As compared to standard production processes, the cooling time is thus extended by up to ten times.” In addition, a cooling air system supplies cooling air in longitudinal direction in order to cool the tubes from the inside. After having passed the paternoster system, the PE foam tubes have almost completely cooled down before they reach the boxes.

First user reports improved extrusion line utilization
The line delivered to ROLS ISOMARKET in Russia is designed for a maximum tube outer diameter of 210 mm and can also be used in double strand production mode for outside diameters of up to 90 mm. As an option, the tube ends can be cut again after the cooling process in order to improve the dimensional accuracy of the tube ends which are often necked down by the gas exchange. “Using the paternoster system, we are in a position to produce thick-walled foam tubes of big diameter and at the same time to improve the performance of the upstream ZE60/KE150 ISO-TUBE Schaumtandex line”, declares Fedor Shvedov, Technical Director of ROLS ISOMARKET. “The exceptional efficiency of the new paternoster system helps us to hone our competitive edge even further.“

ROLS ISOMARKET has built up an excellent reputation as a highly innovative specialist for tube insulation in Russia. Founded in 1994, the company’s 70 staff work in three shifts and currently produce 55 000 000 meters of insulation tubes with different diameters per year for the Russian market. Five ISO-TUBE lines are operated at the Pereslavl-Zalessky site in the Yaroslavl region: i.e. one Schaumtandex line composed of a ZE60 twin-screw extruder and a KE150 cooling extruder as well as four single-stage Schaumex lines. ROLS ISOMARKET is strongly committed to sustainable production. This is why all extrusion scraps are recycled to 100 %.

Source: KraussMaffei Berstorff