Rewinder

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Rewinding machines are used in the production of plastic films , paper , labels , adhesive tapes and packaging materials.

A rewinding machine has one unwind and one or more reels. A roll is unwound on the machine and its quality is checked or its length is changed.

This process often occurs after the roll has been printed or coated. In order to ensure a uniform quality of the material, errors are looked for and, if necessary, cut out of the roll. The defective material is then wound up on a scrap winder and the good material ends are then connected again.

The winding direction of the material can also be changed on a rewinder. Due to the manufacturing or coating process, the material can have different properties on the bottom and top. If necessary, the machine can be used to wind the other side of the material outwards.

Rewinding machines are also used to rewind and shorten rolls to precisely measured run lengths. The run length measurement is carried out either with the measuring wheels lying on the surface or contact-free by special calibrated measuring devices.

A common term in this context is the term “roll doctor” for a rewinding machine, because a badly wound roll can be turned into a well-wound roll. In order to improve the roll quality, side edge controls are used on rewinding machines, which, depending on the sensor used, scan the web edge or a print line and automatically align the roll to be unwound so that the material web always enters the machine at the same point and at the rewind then subsequently has a straight side edge.