multicolor press printing 2 and 3 colors

[maks]

need help. i need to improve in change over time. meaning how to schedule jobs in a 6 and 7 color press when printing 2 or 3 color jobs accompanied by black plate for text and barcode. while regular run is use the first units for kcmy, we always need to bring the black plate to 4th or 5th unit when doing spot color jobs, requiring us to have longer wash up and change over while transferring the black plate and then bringing it back to first unit when priting process colors with special. asking help how to make the kcmy permanent stations without encountering build up or other printing defects. operator says they need to bring the printing units to the very last so not to encounter build up, ghosting or backlash

thanks

 

[SteveSuffRIT]

Sorry, I don't understand the question?
Are you asking where to position the spot colors on a 4/c process press?
If only 4/c, I would put the spot color in the most similar color unit so wash up time doesn't require a longer "color" wash. Red's into Magenta. Blue's into Cyan. Orange's into Yellow.
If 5 or 6 color press, use the open units for sport, always keep process in same units.
Newer presses may allow you to disengage unused units so you don't need to use "lubricant" to protect rollers from friction/heatbuild up.

 

[gordo]

Sorry, I don't understand the question?

Took the words right out of the post I was going to write. LOL

 

[maks]

Sorry, I don't understand the question?
Are you asking where to position the spot colors on a 4/c process press?
If only 4/c, I would put the spot color in the most similar color unit so wash up time doesn't require a longer "color" wash. Red's into Magenta. Blue's into Cyan. Orange's into Yellow.
If 5 or 6 color press, use the open units for sport, always keep process in same units.
Newer presses may allow you to disengage unused units so you don't need to use "lubricant" to protect rollers from friction/heatbuild up.

i edited my post, will this be more understandable. seven color press normally printing kcmy plus 2 or 3 special colors and production normally moves the kcmy everytime there is a reduction in the number or separations or if printing just k and spot colors. thanks

 

[gordo]

Normally, even if your\'re only printing k plus spot colors, you don't move the kcmy units as that causes unneeded washups.
Normally the spot colors are after the kcmy. The reason is to achieve better Ink trapping.
Ink unit position is all about optimizing wet Ink trapping.

 

[maks]

Normally, even if your\'re only printing k plus spot colors, you don't move the kcmy units as that causes unneeded washups.
Normally the spot colors are after the kcmy. The reason is to achieve better Ink trapping.
Ink unit position is all about optimizing wet Ink trapping.

sir, that is what i intend production to do but based on the outcome, not bringing in the printing unit to the last one tends to encounter ink build-up and scratches. any advise to minimize this build up and scratches by not transferring black to the end unit? thanks sir

 

[SheetSqueezer]

What make model and year is the press?

Wet trapping in units spread farther apart is usually not the main consideration on multi-color presses, but ink tack(s) and opacity can be.