uv printing technique

[maks]

i have an offset 7 colors press that we plan to print on foil. the plan is primer, opaque white and process colors plus spot. however, i can not produce good laydown so the recommendation is to run primer first, second pass is opaque then print colors. any suggestion why i not achieving good print in one or two pass? how do you handle this kind of job order?

thanks

 

[Asures]

Before you start the project, have you measured the Dyne level of the Foil?

Wet trapping Opaque White and then trying to put Process ontop without lamping the White generally never works out.

Assuming the Dyne Level is adequate (38 or above), I’d run the white and lamp, put the process or spot ontop. Try to keep the Opaque White somewehere in the density range of 17 - 20. The more white you run, the lower the density will go.

Just some friendly advice.

 

[Cornishpastythighs]

i have an offset 7 colors press that we plan to print on foil. the plan is primer, opaque white and process colors plus spot. however, i can not produce good laydown so the recommendation is to run primer first, second pass is opaque then print colors. any suggestion why i not achieving good print in one or two pass? how do you handle this kind of job order?

thanks

Do you have interdeck UV lamps or just end of press?

 

[maks]

yes. interdeck uv lamps. sorry for the late response. need to run primer first pass. white second pass and the graphics last pass. what am i missing

 

[Asures]

yes. interdeck uv lamps. sorry for the late response. need to run primer first pass. white second pass and the graphics last pass. what am i missing

If the Dyne level of the stock is adequate, Why not run the Opaque White and Lamp, then Process or PMS on top? That's 1 pass vs. 3 passes that you described.

 

[rickix84]

Most likely it's the quality of the foil. If you have the chance, I would run a test on a silver polyester lamination, without primer.

 

[Cornishpastythighs]

we used to run opaque white with 2 hits using lower ink key settings on each unit and lamp between. We also used Gallium bulbs... If you have the print units to do it.

 

[DhavalPX]

i have an offset 7 colors press that we plan to print on foil. the plan is primer, opaque white and process colors plus spot. however, i can not produce good laydown so the recommendation is to run primer first, second pass is opaque then print colors. any suggestion why i not achieving good print in one or two pass? how do you handle this kind of job order?

thanks

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Printing multiple layers like primer, opaque white, and colors on foil in one or two passes is tough because of ink adhesion, drying time, and film thickness. Separating them, as recommended, is often necessary for good laydown and vibrant results due to foil's non-absorbent surface.

 

[Tomas]

I agree. If there are intermediate lamps, it's 1 pass instead of 3.
Yes, for a more even application of the white layer, it is worth putting down the first two sections of white paint and drying them after each layer.
Next, CMYK in line (you can dry it or not - depending on your target dot gain for each color).

If you're having trouble with the white ink sticking to the foil, try a different brand of white ink, adjust the ink's rheology with a reducer, or use a printing blanket with a different surface roughness. It's important to look at the exact appearance of the defect.

It's important not to expose the white too much UV radiation during intermediate drying. This will cause over-polymerization, and even at 38 Dyne or higher, the white will peel off onto the printing blanket of the following sections. Adhesion will be lost. The UV lamp intensity should be adjusted starting with a lower value based on your speed, foil, white, etc.