In the cast film industry, it is well established: the Multi-Touch roll stack from battenfeld-cincinnati Germany GmbH, Bad Oeynhausen. It provides ideal cooling conditions and consequently excellent semi-finished product attributes. This is due to the innovative combination of a two-roll stack for precalibration with several rolls for recalibration, which ensure even roller contact. At its booth at this year’s K, the extrusion specialist will inform trade visitors for the first time about the new Multi-Touch roll-stack for sheet and board applications.
Whenever particularly stringent requirements regarding flatness and thickness tolerances must be fulfilled for the semi-finished product in sheet production, the roll stack is a vital component, as is the case with sheet for refrigerator inner linings, greenhouses or the automotive sector. And this is precisely where the Multi-Touch roll stack is the ideal equipment, since it combines high product quality with enormous line speeds. The secret behind this is its combination of a two-roll stack for precalibration with three, five or seven rolls for recalibration.
This concept has now been further developed especially for sheet and board extrusion. While the first two rolls in Multi-Touch roll stacks for flat film extrusion come with a somewhat larger diameter to minimize sagging, all rolls in Multi-Touch roll stacks for sheet extrusion normally have the same diameter. In this way, and in contrast to the three-roll stacks well-known and established today, the Multi-Touch roll stack provides absolutely even roll contact even at maximum line speeds and thus ensures even cooling on both the sheet’s top and bottom sides. Thanks to the larger number of post-cooling gaps, excellent evening out of thickness tolerances is also achieved. This is how warp-free boards can be produced with optimal flatness and minimal tension.
One of the first Multi-Touch roll stacks for board production has been in operation at a customer’s plant for about a year. This particular line produces about 4-mm-thick HIPS boards, which are subsequently thermoformed to serve as inner linings for refrigerators. Highlights of this line besides the Multi-Touch roll stack are its two 1-75 T6.1 high-speed extruders combined with a small coextruder in size 45, which together reach an enormous output of up to 3 t/h.
The about 70-m-long 2-layer sheet extrusion line, which produces boards with a length of roughly 2 m, is equipped with ultra-modern machine components and impressively demonstrates battenfeld-cincinnati’s complete line competence.
