trouble with tinting

S

spharris

Member
i am running a fairly good run 190,000 sheet of 36 x24 domtar husky offset 92 sm 70# paper on a 8/c komori 2008 yr the job is 4/0 maybe 40% coverage and i keep getting a tint at the very edge back at the tail end of sheet . if i let it go long enough it works its way into the back 4" of the tail of the sheet doesnt start happening until i have ran about 30,000+ sheets it usually only shows up in the red unit i am running van son (quickson inks) if i clean plate it might last 5-7000 more sheets then wont clean up if i change plate i get another 25-30,000 sheets my fountain solution is pressmax 280 2.5oz to gallon and hda64 alcohol replacement 2oz to gallon using regular tap water pretty hard stuff 450+ microhms any help would be welcomed dont want to keep changing 6 red plates everytime i run this job thanks for your time steve
 
Please try upping your etch to 3 oz. and backing off your sub to 1 oz. The wetting agent in the sub may be having an adverse effect and breaking down the ink more rapidly. Also a treated water would help, even if you have to buy distilled water at the Piggly Wiggly. Also, ask your ink maker to incorporate some ph Buffer into your magenta formula. Hope this helps.
 
tint problem

tint problem

thanks d ink man i will try 1oz of replacement and up etch to 3oz i will let you know how it runs tomorrow
 
Try something different

Try something different

Hello, perhaps you could try using a calcium rinse in the Magenta ink train?

Unless you have a single tank for each unit of the press, must fountain solutions don't know what color the ink is, so if it's only the Magenta ink, I suggest looking at the Magenta unit of the press. As Calcium Carbonates are most often used as Optical Brighteners in papers, and as there is likely some Calcium carbonate contained in the Magenta inks as a raw material, try a Calcium Rinse of some sort on your ink forms?

Worth a try, and only takes a few minutes?
 
Try something different

Try something different

Hello, perhaps you could try using a calcium rinse in the Magenta ink train?

Unless you have a single tank for each unit of the press, most fountain solutions don't know what color the ink is, so if it's only the Magenta ink, I suggest looking at the Magenta unit of the press. As Calcium Carbonates are most often used as Optical Brighteners in papers, and as there is likely some Calcium carbonate contained in the Magenta inks as a raw material, try a Calcium Rinse of some sort on your ink forms?

Most times the problem of Calcium buildup results in Blinding, not Tinting, so I don't know if my suggestion will help you?

Worth a try, and only takes a few minutes?
 
Good suggestion Robilious. Also make sure your fountain tank reservoir is between 55 - 60F to enable your water pans to be about 65 F. Temperature and coverage always the most important factors.
 
Have you checked your plate inkers to make sure that they are locked in properly and not oscillating?
 
tinting

tinting

I had this once and I found that the magenta fount tank had contamination. I think it was spirit and cleaned it out and the problem went. It also could be slight emulsification and the damping system is doing its job but it gradually buids up on rear edge of the plate and eventually stains the plates. If it is not the tank be totally radical and try a different ink. If the same result reduce the ph. If still no luck try a different plate. I was told by an ink rep that some papers have a high acid content and this can cause the ph to go awall.
 
I agree with the calcium. Uncoated stock always gives us this problem as well. Use a calcium rinse like roller relief then follow up with a good cleanup.
 
tinting

tinting

Hi,we have a 30,000 speed machine..recently(almost a week) we are facing tinting problems i.e. the non-image area has a thin film of ink deposited on it...We are using the same fountain solution and ink for the last 4 months and was absolutely fine.Suddenly this problem cropped up and ink has been changed but without any effect..We are using RO water.

Please help.
 
Hello, perhaps you could try using a calcium rinse in the Magenta ink train?

Unless you have a single tank for each unit of the press, most fountain solutions don't know what color the ink is, so if it's only the Magenta ink, I suggest looking at the Magenta unit of the press. As Calcium Carbonates are most often used as Optical Brighteners in papers, and as there is likely some Calcium carbonate contained in the Magenta inks as a raw material, try a Calcium Rinse of some sort on your ink forms?

Most times the problem of Calcium buildup results in Blinding, not Tinting, so I don't know if my suggestion will help you?

Worth a try, and only takes a few minutes?
 
 
I worked for a company that we did use the calcium wash about once a week. The rest of the washups we used a 50 50 viniger mix with water to remove some of the deposits left in the rollers. This kept things clean and worked very well and kept costs down as viniger was cheaper than the calcium cleaner.
 
Try adding gum aribic to the fountain solution. If this helps you might need to change to a fountain solution that has more gum aribic to help keep the plate desesitized.
 
Plates

Plates

It sounds to me like it could be your plates, try changing the developer, I have come across a similar issue in the past.
You mentioned if you change your plate you get another 30k so the plate is obviously breaking down.
 
re Calcium Carbonates for Paper

re Calcium Carbonates for Paper

Gentlemen, Calcium Carbonates (PCCs) are just used as "Fillers" not as "OBA's


Brightness and Whiteness are not the same -- a Pdf on the subject


" I hope you wiil find it of interest and value"


Regards, Alois - Senior Member with 40 years experience in "Lithography "
 

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