In rewind slitting the web is unwound and run through the machine, passing through knives or lasers, before being rewound on one or more shafts to form narrower rolls.
The slit material is rewound on paper, plastic or metal cores on the exit side of the machine.
Depending on the industry and the product that is being slit these machine can run between 10m/min (special metal webs) and 5000 m/min (paper making process).
Examples of materials that can be cut this way are: adhesive tape, foam, rubber, paper products, foil, plastics (such as tarps and cling wrap), glass cloth, fabrics, release liner and film.
Also, the geometry of these rolls is determined by specific tolerances in addition to the type of material and workpiece thickness.
[4] The material is fed from the uncoiler, through the nip between the two circular cutting wheels (one on top and another underneath), and then re-wound in slit pieces on the recoiler.
The unwind stage holds the roll stably and allows it to spin; it is either braked or driven to maintain accurate tension in the material.
Closed-loop control of the winding tension using feedback from load cells provides the total tension-control system required for running tension-sensitive materials.
This may involve purchasing large rolls of plastic film such as biaxially orientated polypropylene (BOPP) which is then printed to the customer's design and coated with cold seal adhesive for use on high speed packaging machines.