Inside this month’s issue: High flexibility, reliability, operator friendliness, sustainability, productivity as well as cost effectiveness… This is what producers and converters in various industries are looking for in their slitting and winding solutions, says GOEBEL IMS
Finding the right slitter rewinder for specific requirements is not always simple. Different machines with various winding concepts make it difficult.
One machine concept to consider when it comes to converting materials such as paper, board, film, aseptic packaging materials and aluminium foil is the single shaft centre-driven winding concept. This machine category is relatively simple, yet it offers many advantages when designed and manufactured properly. For web widths between one and 2.5 metres, a single shaft can be the best solution. In practice, winding delicate materials on driven cores has proven effective. The transmitted force into the cores, generated from the drive, creates the necessary web tension. Depending on the required material tension and the actual diameter of the finished rolls, a specified torque needs to be set in order to ensure the right web tension at the winding point. With the centre-driven winding concept, the pressing force is applied from separate contact rollers from the outside.
The single shaft centre-driven winding concept and slitting and winding quality allows slitter rewinders to handle the web with such delicacy that even pressure sensitive materials with a very delicate surface can be wound without any risk of damage. This machine concept is therefore the ideal solution for these applications. A waste-free, smooth production process is guaranteed when the slitter rewinder is equipped with a proper reel unloading system.
The single shaft centre-driven winding concept and efficiency
The loading and unloading of cores and finished rolls is a determining factor for the efficiency of the whole converting process. With the single shaft centre-driven winding concept, the cores for the finished rolls can be placed onto the winding shafts in just a few seconds. The cores do not need precise measuring to be correctly positioned; it is sufficient to fit them onto the shaft one beside the other. A final adjustment can easily be made based on the actual positions of the webs.
The process of unloading the finished rolls is simple and fast with the single shaft centre-driven winding concept. One option is to unload the rolls to the floor and extract the shaft with an extractor. Another solution is to keep the shaft overhanging at one end and pulling out the pack of rolls after depositing them onto a side-moving trolley.
With single shaft centre-driven slitter rewinders, even the changing of slit sizes is easy. The reason being that only the position of the knives needs changing while there is no need to adapt the winding section. Once the shaft is dressed with the cores of the new size to be slit, the job is done. For those requiring an even higher productivity, the machines can be equipped with an automatic knives positioning system, as the cost of this type of equipment has decreased in the last few years, while their efficiency and reliability increased significantly.