Catering to the demanding production of hygienic films, the new Culisse winder is said to offer special winding and in-line slitting capabilities.
Catering to the demanding production of hygienic films, the new Culisse winder is said to offer special winding and in-line slitting capabilities. Developed by ER-WE-PA, the German technology company for extrusion and coating equipment of the Converting Systems Group of Davis-Standard, the new winder is capable of cutting extra wide film webs into more rolls than usual. It is mainly targeted for the production of hygienic films such as diapers, sanitary towels, sterile flat products for operating theatres, and for products in which a wetness barrier is combined with water vapour permeability.
Unlike a turret winder, where both winder shafts turn through approximately 180 degrees in a semi circle shortly before finishing one roll, the movements of the shafts are different in the new winder. The active winding shaft first moves into the centre of the turret bull gear and then the empty winder shaft turns 180 degrees to the winding position. Since the active roll is in the centre, there is said to be no negative effect on the winding quality.
The new winder also has two lay-on rolls instead of one. Shortly before the indexing cycle, the second roll starts up and takes over the function of the first roll. “There is always at least one roll active, which presses out air in a controlled process, so that the layers
of the finished roll are wound ideally for unwinding for further processing,” says Volkmar Mehnert, product manager at ER-WE-PA Davis Standard.
The Culisse can work with a slit roll width as small as 80mm. Up to 50 rolls, for example, can be wound and slit in-line from a film width of 4m, says the company. When 50 lanes of web are to be cut, 51 knives are used. The same number of knives are on stand-by for blade change. “The changing of knives is done on line during production, since there are always two knives available for each slit,” he says.
The winder is also said to feature a precise slitting technology. It utilizes two spreader (banana) rolls, which serve to separate the material after slitting. Chris Barton, director sales and marketing at ER-WE-PA Davis-Standard, says: “We use extra-long spreader rolls, to achieve an even, wide distance between the individual lanes. A laser positioning system makes work a lot easier for the operators.”
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