Consumables Parts and Spare Parts
44
/
55
7.2Common plate-making problems and causes
Table 7-2: Common plate-making problems and causes
No
Problem description
Cause analysis
Typical results
1
Dots shoulder thin, low
run length, dots holding
not strong
1.Main exposure time too short
2.Plate washing time too long
3.Imaging power too low
4.Dot compensation too low
5.Back exposure time insufficient
2
Scanning lines/bandings
1. Imaging power too low
2.Out of focus
3.lens dirty/dusty
4.Plate thickness value incorrect
3
Image not sharp
Main exposure time too long
4
Negative inversion
low/not visible
1.Main exposure time too long
2.Plate washing time too short
5
Dots relief too shallow
1.Back exposure time too long
2.Plate washing time insufficient
6
Thin lines loss/bent
1.Main exposure time insufficient
2.Back exposure time too short
3.Drying time insufficient
4.Brush pressure too much
5.Plate washing time too long
7
Plate surface uneven
1.Drying time insufficient
2.Plate washing time too long
3.Bottom of plate dirty
4.Plate storage inappropriate
8
Plate surface sticky
1.UVC exposure insufficient
2.Plate washed not thoroughly
3.Washing/Spraying insufficient
4.Drying time too short
9
Plate surface
wrinkle/bumps
1. Main exposure time insufficient
2.Plate washing time too long
3. Washing/Spraying insufficient, or wash solvent
not drawn dry
4.Plate handling not appropriate
10
Plate fracture
1.Curing time too long
2.Sticky treating time too long
3.Plate being oxidized
11
Length deviation
1.Perimeter correction incorrect
2.Plate layout direction different
