Operator's Manual
3950 Series
Perforating - Scoring - Slitting
116
Perforating Tools
Purpose of perforating:
To avoid creasing when making crossfolds.
Air can escape from the folded sheet through
the perforations.
Perforating (1) is done by the serrated perforating knife (2) and the straight-edge
lower knife (3).
1
2
3
Various perforating knives are available which differ in the type and number of teeth.
Their usage is determined by the type of paper and the kind of perforating job.
Light paper grades:
short cuts, many teeth
Heavy paper grades:
long cuts, few teeth
The perforating knife is normally mounted on the upper delivery shaft and its counter-
part on the lower shaft.
Knives for push-through perforation are always mounted on the upper shaft.
When perforating and slitting light stock the paper may stick to the knife.
A stripper is used to prevent this.
The stripper should be mounted as close as possible to the perforating knife.
Paper stripper for upper
perforating knife
Paper stripper
for lower
perforating knifed
Waste stripper
for cut-out
Waste stripper for
ridgeless perforation
!
When setting the strippers, take care that they do not touch the delivery shaft!
!
If the sheets are only perforated and
not folded, the telescopic hold-downs
(4) should be used to support paper
transport on the delivery table.
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