Soft nonwoven requires specific precautions in end-of-line operations to maintain the qualities obtained during the production process. In some cases, when processing particularly soft and bulky materials, we have to evaluate alternative solutions to traditional rewinding to obtain the best result.
If the goal, for example, is to produce a small-format reel containing a high number of meters of soft and particularly delicate nonwovens, using a standard rewinder could lead to an unsatisfactory result, obtaining a voluminous and not very dense reel compared to customer requirements.
Furthermore, when transporting large reels there are evident geometric constraints, in addition to the fact that the type of nonwoven in question can be damaged during the various handling operations.
This is why A. Celli offers, as part of the F-LINE® product range, two alternative solutions to rewinding, each with its own peculiar characteristics based on the needs of the converter, capable of preserving the softness and bulkiness of the nonwoven: Spooling and Festooning.
What is Spooling
The A.Celli F-LINE® lines dedicated to spooling are based on a system capable of wrapping narrow stripes of particularly soft nonwoven around a shaft. Thanks to the transversal movement of this shaft it will be possible to obtain, with a process ideally similar to the winding of the yarns, a final reel with an overall width greater than the stripe itself and containing a number of meters of material higher than a standard reel, with obvious advantages in terms of productivity in the subsequent converting phase.
As regards the technical data, the spooling lines are able to process nonwovens with basis weight from 15 to 200 gsm wound in master rolls with a maximum diameter of 2000 mm and width from 350 to 1200 mm (without considering customized solutions able to manage larger formats), all at a maximum speed of 800 m/min and using up to 12 spooling heads. Thanks to a variable slitting width from 35 to 140 mm, it will be possible to obtain finished rolls of soft nonwoven with a width from 400 to 850 mm and a diameter up to 1200 mm.
A spooling line ideally comprises three sections: unwinding, slitting, and actual spooling. Therefore, starting from the jumbo roll, we obtain a number of nonwoven stripes equal, at most, to the number of spooling heads and of reduced width, which will subsequently be wound around the winding shaft. In order to obtain a correct winding of the product in the object, the tension is carefully controlled at each stage of the winding process and the single stripe is duly positioned to produce finished rolls characterized by a flat surface.
Festooning: an alternative technology to rewinding
The F-LINE® festooning lines, a novelty of the A.Celli product range, are used as an alternative to spooling and rewinding, depending on the specific characteristics of the nonwoven to be processed.
The idea behind this technology is as simple as it is innovative: unlike rewinding and spooling, with the festooning process we use devices called festooning heads to obtain bales by depositing the individual stripes on a special mobile platform by combining three movements along the reference axis:
- The X-axis (machine direction): Oscillating movement of the festooning head
- Y-axis (transversal to the machine direction): movement of the mobile platform below
- Z-axis: the raising of the upper platform as the height of the bale varies during its formation.
Each layer of the bale is therefore formed by a continuous strip of nonwoven deposited with a “zig-zag” movement. After the completion of each layer, the upper platform, where the oscillating arms of the festooning heads are hinged, will rise – with an adjustable stroke – to allow the laying of the next layer on top of the previous one.
When the bale reaches the predetermined dimensions the platform lifts completely to allow the extraction of the bale itself, an activity that can be fully automated by using conveyor belts to move the bales to a picking area or to another conveyor belt connected to a packaging unit.
The bales, once completed, can be wrapped with stretch film or compressed, in order to eliminate the void between the various layers, thus increasing the density of the pack and increasing efficiency in transport operations.
The result is a finished product that lends itself to greater ease of storage and handling by optimizing, for example, the space in containers at the time of shipment. Furthermore, thanks to this solution, the converter has access to both ends of the stripe that forms the single bale, thus allowing to prepare the necessary joints in advance and to obtain significant advantages in terms of productivity.
Finally, as regards the technical characteristics, the F-LINE® festooning lines can be equipped with up to 24 festooning heads (although it is preferable to install two machines with 12 heads each for greater flexibility) and are able to process nonwoven master rolls with a maximum diameter and width equal, respectively, to 1800 mm and 750 mm.
The basis weights supported are between 15 and 200 gsm, the slitting width varies from 35 to 135 mm and the maximum operating speed is equal to 150 m/ min, while the finished bales will have maximum dimensions equal to 1200 x 1000 x 1700 mm.
More info, visit at: https://www.acelli.it/