GRAVURE TROUBLE-SHOOTING GUIDE

Transcription

1 DEFECT PRCE PRBEM PRBABE CAUE TET PBE REMEDE CHATTER Blade angle too sharp Flatten blade angle Too much blade pressure Reduce blade angle Blade too sharp High pigment ink sharpening blade olids test Replace ink if out of spec Uneven ink flow from fountain Dried ink on fountain Fountain set up incorrectly Fountain too far away from cylinder Clean off the fountain Remount fountain Adjust fountain closer to cylinder K FW Too little ink flow from fountain nk flow valve not open enough pen valve wider / check for blockage nk filter clogged Change ink filter nk pump not operating correctly Pressure gauge Replace ink pump Too much ink flow from fountain Fountain baffles are plugged or bent Fountain too close to cylinder nk flow valve open too wide Clean / adjust baffles Adjust fountain away from cylinder Close valve slightly ow temperature in dryer heat gun Raise dryer temperature nk not drying completely on web ow air flow in dryer magnehelic ncrease dryer air flow ow steam pressure to dryer otify maintenance Press speed too high (small dryers only) Decrease press speed High ink viscosity olvent evaporation from ink viscosity test lowly add more solvent to ink PCKG ncorrect pressure on impression roller Too much pressure on mpression roller measure nip flat area Decrease roller pressure Too little pressure on impression roller measure nip flat area ncrease roller pressure mpression roller is the wrong durameter durometer Tester Change roller durometer Dirty impression roller Defective / uneven impression roller Clean the impression roller Change the impression roller Chill rollers too warm Water supply not cold enough / not flowing heat gun otify maintenance

2 DEFECT PRCE PRBEM PRBABE CAUE TET PBE REMEDE olvents blended incorrectly Have ink room adjust solvent blend ncorrect solvent blend G.C. test (Add PA for P-200 ink system) High room temp causing evaporation otify maintenance Blade angle too sharp Flatten blade angle Blade too thin Replace Blade C H A E G High ink viscosity olvent evaporation from ink viscosity test lowly add more solvent to ink Cylinder engraved incorrectly microscope De-chrome & Re-chrome cylinder Cell walls on cylinder too wide Cylinder worn De-chrome & Re-chrome cylinder Too much air blowing on cylinder cum blower setting too high ower air setting or turn off scum blower Fan or draft blowing on cylinder puff tester Redirect air flow Chill rollers too warm Water supply not cold enough / not flowing heat gun otify maintenance Too much pressure on mpression roller measure nip flat area Decrease roller pressure ncorrect pressure on impression roller mpression roller is the wrong durameter durometer Tester Change roller durometer Defective / uneven impression roller Change impression roller High room temperature otify maintenance nk temp too high nk not thoroughly mixed mpression nip point friction Too much agitation of the ink nk pump not operating correctly pressure gauge nstall ink chillers Decrease impression roller pressure Check the ink pump Change ink filter Unclog agitator elbow Replace pump

3 DEFECT PRCE PRBEM PRBABE CAUE TET PBE REMEDE Add new ink to old ink ow ink Viscosity Too much solvent in ink viscosity test Replace ink nk pump not operating correctly pressure gauge Change ink filter M T T E Unclog agitator elbow nk is not thoroughly mixed Replace pump nk not properly mixed at formulation Return to ink room for mixing The ink has been "HCKED" olvent poured too quickly into ink Replace ink Blade angle too flat harpen blade angle Blade too low relative to nip point Raise blade closer to nip point Too little pressure on the impression roller measure nip flat area ncrease pressure to the roller nsufficient pressure at the nip point mpression roller is wrong durometer Change the roller to a harder durometer Uneven wax coating weight on stock paper Change the paper ncorrect cylinder engraving Engraving too deep / too shallow Replace the cylinder Dried bits of ink in the ink Clean / change blade Filter ink TREAK Dirty blade Metal bits in the ink Paper dust contaminating blade Filter ink with magnet Check press vacuum system Dirty rollers contaminating blade Clean rollers Blade not oscillating Mechanical failure otify Maintenance

4 DEFECT PRCE PRBEM PRBABE CAUE TET PBE REMEDE K. P A H Too much ink flow from fountain nk flow valve open too wide Close valve slightly nk flowing over splash guard Blade angle too flat Adjust blade angle nk splash guard leaking plash guard set up incorrectly Reset splash guard inside ink pan Hose to fountain leaking Fountain baffle / ink splash deflector is missing Hose fitting not securely attached Hose gasket worn, missing or broken Hose has a hole in it Baffle set up incorrectly Tighten hose fitting Replace gasket Replace hose Replace fountain baffle et up ink splash deflector nk film not drying on the non print area of the cylinder ot enough air blowing on cylinder Press speed too fast (small dryers only) Turn on scum blower ncrease scum blower air setting Decrease press speed C U M Buff the cylinder Cylinder surface is too rough Cylinder not polished enough RZ test Replace the cylinder High ink viscosity olvent evaporation from ink viscosity test lowly add more solvent to ink Worn blade Running for long periods of time Replace the blade Rough / high cylinder edges Have cylinder filed down ncorrect solvent blend in ink olvents blended incorrectly G.C. test Have ink room adjust solvent blend (add PA for P-200 ink system) Blade angle too flat Blade too close to nip point Blade too thick harpen blade angle ower blade away from nip point Change blade

5 DEFECT PRCE PRBEM PRBABE CAUE TET PBE REMEDE High ink viscosity olvent evaporation from ink viscosity test lowly add more solvent to ink C R. F F Add new ink to old ink ow ink viscosity Too much solvent in ink viscosity test Replace ink Color mis-match at the ink room Wrong formulation used Replace ink nk pump not operating properly pressure gauge Change filter Unclog agitator elbow nk not thoroughly mixed Replace pump nk not properly mixed at formulation Return to ink room for mixing Blade angle too sharp or flat Adjust blade angle Blade too high / too low relative to nip point Adjust blade hieght Cylinder cells too deep / too shallow Blade too thick / too thin Cylinder is incorrectly engraved Replace blade Wax coating weight on paper uneven Defective coating on stock paper Change paper Dried bits of ink in ink Clean / change blade Dirty blade Metal bits in ink Filter ink Filter ink with magnet DRAG Paper dust contaminating blade Dirty rollers contaminating blade Check press vacuum system Clean rollers Blade angle too sharp or flat Blade too low relative to nip point Blade too thick [ DRAG CTUED EXT PAGE ] Adjust blade angle Raise blade closer to nip point Replace blade

6 DEFECT PRCE PRBEM PRBABE CAUE TET PBE REMEDE Chrome nodules on cylinder Cylinder buffed incorrectly Re-buff cylinder DRAG (CTUED) Rough blade Blade polished incorrectly Replace blade Blade not oscillating Mechanical failure otify maintenance Worn blade Running for long periods of time Replace blade Chrome nodules on cylinder Cylinder buffed incorrectly Re-buff cylinder Cylinder not polished enough RZ test Re-buff cylinder Contamination under the blade Re-buff / replace cylinder Clean / change blade E ines are scratched into the cylinder icked blade Fountain set too close to cylinder Contamination in ink Blade polished incorrectly Filter ink Finlter ink with magnet Check press vacuum system Clean rollers Adjust fountain setting away from cylinder Change blade Filter ink Change blade Rough / high cylinder edges Have cylinder edges filed down Blade not oscillating Mechanical failure otify maintenance ines are in the wax coating on the paper Defective coating on stock paper Change the paper

7 DEFECT M G. P R T PRCE PRBEM Cylinder design incorrect Worn cylinder nsufficient pressure at the nip point Cylinder filled in with ink PRBABE CAUE TET PBE REMEDE ncorrect artwork used ver-use De-chrome & Re-chrome cylinder Cylinder buffed too much Blade angle too sharp or flat Flatten blade angle Blade angle too sharp Flatten blade angle Blade too low relative to nip point Raise blade closer to nip point Too little pressure on the impression roller measure nip flat area ncrease pressure to the roller mpression roller is wrong durometer durometer tester Change roller to a harder durometer Uneven pressure on impression roller Balance impression roller pressure Defective or worn impression roller Replace impression roller Cylinder mis-aligned in carriage Remount cylinder High ink viscosity viscosity test lowly add more solvent to ink Clean / scrub out cylinder with solvent Too much air blowing on cylinder Turn off scum blowers or redirect fans Clean / scrub out cylinder with solvent Blade too far from nip point Move blade closer to nip point nk pan too low Adjust ink pan nk temp too high thermometer nstall ink chiller

8 DEFECT B C K G PRCE PRBEM nk not drying completely on web Rolls wound too tightly nk skinning over PRBABE CAUE TET PBE REMEDE ow temperature in dryer heat gun Raise dryer temperature ow air flow in dryer magnehelic ncrease dryer air flow Clean air nozzles Adjust air nozzle angle ow steam pressure to dryer otify maintenance Press speed too high (small dryers only) FPM tach Decrease press speed ncorrect solvent blend G.C. test Have ink room adjust solvent blend Too much tension on web Decrease press tension Coating on paper uneven Change the paper High temperature in dryer ower dryer temperature High air flow in dryer Decrease dryer air flow Press speed too high Decrease press speed ncorrect solvent blend G.C. test Have ink room adjust solvent blend ow temperature in dryer ncrease dryer temp