If your Kompac runs too wet, it can be due to paper fiber contamination from the stock you are running.
When printing long runs on NCR, Vellum Bristol, or other linty stocks that releases paper fibers to the blanket, you will notice that at 8,000 to 10,000 impressions, the normal ‘rolling’ fountain solution bead in Kompac nip looks milky, uneven, and ‘lumpy’ near seals.
This lumpy condition is due to a build-up of paper particles (paper fiber, clay, coating) from the stock suspended in wetting solution.
If fountain contamination is allowed to build-up too long, the ‘inked surface of your Kompac form roller becomes impregmated with water-absorbing paper-fibers, where it then becomes more like a ‘molleton’ form roll, rejecting ink and carrying too much water.
When you see this lumpy condition in your Kompac, suck-it-out with your syringe at your next plate-change or paper reload.
If you make this practice a routine procedure, you will produce more consistency color and operate at higher production speeds.
Note: Also keep an eye out for paper lint/fiber build-up on the form roller at the ‘center’ (under bottle mount) of Kompac when printing ‘window envelopes, especially on longer runs.
Window envelopes that have been cut by a ‘dull’ window cutting-die leaves loose fibers exposed around window edges.
When this happens, the image gets lighter and lighter regardless of ink feed, and you waste alot of time and envelopes before discovering the real cause.
When this occurs the only solution is to do a quick clean-up of Kompac and refresh solution to begin anew. (Note; This is an excellent application for using a small 2″ X 4″ Stick-N-Strip Spot Blanket Patch. With a small Stick-N-Strip blanket patch that accomodates ‘only’ the image area, there are no blanket surface to contact the window area of envelope which totally eliminates fiber,and toner scatter ink build-up!
Paper bi-products are the primary roller contaminates that sensitize the Kompac form rolls’ surface, and is the primary roller contaminate that makes the use of a good water misible roller wash so important.
DO NOT use a ‘fast dry’, single step blanket wash to clean your Kompac unless its the final step to remove residue from water misiable wash!
Fast dry solvents evaporate way too fast to disolve and remove ink pigments, and fast dry washes ‘do not’ desolve paper contaminates.
Only water misible, water soluable ‘detergents solvents’ do!
Always clean your Kompac with a good water-misible detergent based wash to desolve and remove both ink and paper contaminates from your Kompac form roll!
Note: The use of TimeSaver Seals and our KwikVac will make cleaning/purging your Kompac much more effecient!