TONING ON UNIT 1

[maverick1971]

Hi Everyone,

We are running 2 QMDI Classics and recently, we have run some tests on some alternative Waterless inks. The inks appear very similar to TOYO inks in terms of viscosity and even appearance of colours. On testing the inks we got good resultrs with the exception of one problem - TONING ON UNIT 1

On both our QMDI's we run CYAN on unit one which works perfectly with Van Son and TOYO inks. However, due to ink supply problems, we are looking for an alternative to these two brands of inks.

Has anyone experienced toning on only 1 of the four units with any particular brand of inks? Without any change in roller settings or temp. settings, we switched back to Van Son inks on unit 1 and immediately the problem went away.

What could be the cause of toning on one unit only with one brand of ink and not with another? Does anyone have any idea/s on what the solution could be?

Should I try reducing the temperature on the chiller?
Is it just the composition of the particular colour of this brand of ink that is causing this problem?
Should we persevere with trying to eliminate the toning or will this problem persist because it is ink specific?

Any input would be most welcomed.

Many thanks

 

[alibryan]

One thing I can tell you for sure is that waterless printing ink can be very finicky. From my experience, certain brands are definitely better than others, and you have already been using one of the best ones made. If it was me, rather than trying to find another brand, I would try to find another supplier.

 

[Paul Cavanaugh]

I do not recommend turning the temperature down below 21 C. The cooling system also cools the electronics and can cause condensation on the Imaging Heads and in the LDM's. If your other inks work, stay with what you have.

 

[mrheidelberg]

Also check your roller settings, that can help

 

[maverick1971]

Hello Gentlemen - Thank you guys for your responses. I am quite convinced that we have an issue with the Viscosity of the CYAN ink. We have tried adjusting rollers but I think it is a temperature issue. However - I have opted NOT to lower the temperature as PAUL advised as the machine runs fine with Van Son inks at the current temp (20 Degrees set at the chiller) and we have NO condensation issues. I do not want to change anything on the machine which was running fine with the Van Son inks as we had no other issues with the current settings on the press. Adjsuting the rollers did improve the problem slightly but it did not go away completely.

The other 3 colours of the new ink run perfectly fine and we are now speaking to the producer of the inks to see whether they could increase the viscosity of the CYAN to bring it in line with the other three colours. Do any of you agree with that approach? Your input / feedback would be most welcomed.

Thank you again for your valued responses.

Kind Regards

Shawn