Winder and rewinder
◼ First winding happens on paper
◼ Second winding is on the main winder
for smaller rolls.
◼ Some part of the production is normally
handled on the rewinder.
◼ Reasons for rewinding can be:
• Rewinding defect rolls
• Making splices and removing faults
• Slitting narrower rolls
• Changing roll diameter or core
◼ If you need a good rewinder of trim
width 2500 mm please contact me:
Roll quality and rewinder
◼ Drum diameters of a two-drum winder have big effect on roll quality and
winder capacity. Rewinder drums should have same diameter as the
Good rewinder – large
diameter drums (850 mm)
Common rewinder – small
diameter drums (500 mm)
Effect of speed changes
◼ On a rewinder there are more accelerations and decelerations than on the
main winder. These have effect on the roll structure. In practice
deceleration always hardens the roll and acceleration loosens.
◼ During deceleration roll weight will be more on the front drum and the nip
there can be too hard causing roll defects.
Picture: David Roisum
Effect of splicing on roll structure
◼ Rolls having winder splices are never as
good as normal rolls.
◼ If the splice is made because of web break
in the previous winding, the winder must be
decelerated before the splice, which
increases web tension.
◼ During the splicing the web can be loose,
which decreases roll hardness.
◼ After the splice winder is accelerated,
which reduces roll hardness.
◼ On top of this loose part nip effect is higher
and roll hardness is increased again.
◼ When drum diameter is higher, nip effect is
smaller. This is one reason that rewinder
drum diameter should be high.
Picture: Pekka Komulainen
Requirements of good rewinder
◼ Good rewinder should have the following similar
properties as main winder to make same roll quality with
• Large diameter drums for good roll quality and smooth
high capacity winding
• Electric unwind for fast acceleration and deceleration
• Automatic trim change in case of several roll widths
• Accurate double spreader for efficient separation of
◼ If you need a good rewinder of trim width 2500 mm please
contact me: Pekka.Komulainen@clarinet.fi