Service Manual 10 Cutting Quality Enhancement Tips
10.1 Trouble occurring/cutting problems and their remedies
1/09 PERFECTA 115 / 132 / 168 / 225 – TS 61
PERFECTA Schneidemaschinenwerk GmbH D-02625 Bautzen Schäfferstr. 44 Tel.: +49-3591-556-131 to -133 Fax: +49 3591-556-139
10. Cutting Quality Enhancement Tips
Both the knife and the machine are a uniform cutting system. Many factors of this unit
can affect the cutting quality. Based on our experience, we have listed a few problems
and their probable causes to assist you in overcoming any potential trouble.
This list can only be a part of the variety of possible problems. Please feel free to ask
us for advice as we are always eager to solve with you any problems that might occur.
Caution:
Do not use any knives other than Original PERFECTA's.
Replace dull and improperly resharpened knives. These can result in both
damage to the machine and in their uselessness.
10.1 Trouble occurring/cutting problems and their remedies
10.1.1 Wavy cutting
Vertical shading which can be seen and felt as wavy zones.
Figure 42: Vertical shading.
Cause Remedy
Too much ink at various positions cau-
ses high thickness differences on the
paper sheets. This is the reason for
inhomogeneous clamping pressure at
positions containing much ink. At such
positions which slightly swell, the knife
will cut worse.
Applying a felt or foam pad between the
clamp and the paper pile can provide for
uniform pressing.
Knives which were overheated during
resharpening have soft zones which get
dull very quickly.
Resharpen the knife with sufficient coolant
supply. The soft zones must be com-
pletely removed.
Too acute a cutting edge angle causes
swelling at densely printed positions.
Grind a bigger angle (for example, from
22° to 24°).
Use of a knife quality not suitable for the
type of paper.
Use a different type of knife (carbide).
Table 4: Causes of and remedies to vertical shading.
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