Originally developed for high-tech applications, it now also conquers standard segments: the multi-touch roll stack for sheet and board production from battenfeld-cincinnati Germany GmbH based in Bad Oeynhausen. In fact, the roll stack creates ideal cooling conditions thanks to its special process technology concept, and thus delivers high-quality semi-finished products, and all of this with narrow thickness tolerances and high line speeds, too. After the sheet industry, more and more board production customers now also rely on the modern roll stack. One of these is the Turkish Vestel A.S. Group headquartered in Manisa, which recently purchased a complete 2-layer line for Vestel Home Appliances Refrigerator Factories to produce HIPS boards. In addition to the multi-touch roll stack, the core competencies of this line include three high-speed extruders, which provide its enormous output of up to 3,000 kg/h.
The globally active Turkish corporation, which has been a member of the Zorlu Group since 1994, consists of 28 different companies and serves industries such as makers of consumer electronics, household appliances, mobile technology and LED lighting. The companies united under the roof of the Group include famous brands such as Telefunken, Graetz, Techwood, Finlux, Luxor and Vestfrost, as well as Hitachi, JVC and Toshiba. Vestel is the export champion of Turkey for 22 years in the electronics and home appliances industries through its exportation to 156 countries with a diversified product range based on technology and design development competency.
For its plant in Manisa/Turkey, Vestel Home Appliances, who can already look back on a long-standing business partnership with the German machine manufacturer battenfeld-cincinnati, most recently purchased a complete line to make HIPS sheet for door and interior compartment linings in refrigerators. A vital consideration for the white goods manufacturer was to have a powerful line with a high performance in terms of sheet quality. This is why the modern extrusion line with its 75-40 T6.1 and 45-32 T2.1 high-speed extruders and multi-touch roll stack was chosen.
High-speed extruders from Bad Oeynhausen come with a very compact design and yield an enormous output with their high screw speeds of up to 1,500 rev/min. The melt’s residence time inside the extruder is long enough to achieve optimal homogenization on the one hand, and on the other hand short enough to prevent mechanical or thermal damage to the material. At Vestel Home Appliances’ Refrigerator Factories in Manisa, two size-75 high-speed extruders take care of plasticizing the core layer of the boards, which are up to 6 mm thick and up to 1,200 mm wide, while a co-extruder applies the glossy surface layer. From the extruders, the perfectly processed melt passes through a flat-sheet die into the multi-touch roll stack with 2,400-mm-wide rolls. Thanks to a combination of a two-roll stack for pre-calibration with several re-calibration rolls, which ensure even surface contact with the rolls, it produces excellent semi-finished product attributes, that is, optimal flatness with narrow thickness tolerances. While the excellent flatness is important for further processing of the boards by thermoforming, the reduction of thickness tolerances means hard cash. With the modern line, Vestel has been able to reduce the thickness tolerance of its HIPS sheets by some 50 % compared to its existing lines equipped with conventional three-roll roll stacks. With a line output of 3,000 kg/h, this alone yields annual cost savings in six-digit euro figures.
The overall concept, with its ecological as well as economic advantages due to reduced raw material consumption, has already been favored by several other customers. For example, battenfeld-cincinnati recently installed a comparable ultra-modern sheet line for a German customer at its production plant in Poland. The specialty in this case is that the thickness range of the semi-finished products being made can vary from 1 to 6 mm, and a winder for sheet up to 2 mm thickness as well as a stacker for thicker boards are integrated.
