Information on Flexo Printing &
Ink Formulation


What Can Cause Printing Problems

Metering Roll Web Tension
Gears Humidity
Plates Pumps
Sticky Back Laminates
Blades Overprints
Anilox Artwork (design)
Adhesives Traps
Substrates Inks

Flexo Printing Process

*Of all possible variables; Which variable can adjust to compensate for mechanical deficiencies?

The Inks!!

So, are we troubleshooting inks or using inks to troubleshoot the mechanics?

Or Both?

Using Inks to Trouble Shoot
- Why is there a need to adjust the inks - What is needed to trouble shoot inks,
Why is there a need for ink additives?

First we Need to understand how inks are made.

Inks Are made up of Four Basic Components

1.) Binders

Binders are usually referred to as resin types, they are the main carriers that will determine the properties of an ink.
(Acrylic Solutions, Polyesters, Epoxies, Urethanes)

2.) Additives & Modifiers

Additives and modifiers enhance the properties of the binder and in many cases allow the product to function. The list of modifiers is infinite and combinations of agents are being developed every day.

3.) Pigments

Pigments are by far the most critical portion of any printing ink. Without pigment there would be no reason to print. Pigments are also the most expensive part of the ink formula and will determine the final properties of the ink.

4.) Diluents or Carriers

For water based inks
ex: (Water Amine blend, Co-Solvents, Alcohols or Glycols)

 

 

The Ink Formula

The ink formula will determine the amount of maintenance on press; the less maintenance required from inks, the less need for trouble shooting. With that said, inks are formulated to achieve specific results. To lower the cost of an ink, the formulators options are limited. To increase resistance properties the formulators need to add more resistance products.

Formulating for
lower cost effects
print quality and ease of use

Web Tension

Formulating to increase
resistance, effects print quality
and ease of use.

Low Cost

Formulating for best
print performance

High Resistance

 

 

Formulating for Best Print Performance

Web Tension
* The Lower the Cost, The More likely print problems will occur *

Inks formulated to
increase resistance properties

* The Greater Resistance, The More likely print problems will ocur *

Pigments are run through mills fast resulting in larger pigment particles
Less expensive pigment result in dirtier more opaque colors
Lower end pigments increase likelihood of bleed, staining and fade
Binders with lower solids results in less gloss and lower Newtonian flow
Less effective additives are often used to control cost
Clay fillers are used to reduce cost; Which will cause settling and uneven distribution from one run to another
High resistant pigments are used, many times these pigment are harder to grind and result in larger particle sizes
Many of the higher end pigments are slightly incompatible and may result in bodying
Co-solvents or cross lining agents may be required to achieve additional resistance properties.
High end co-polymers may be required to achieve results.
Due to co-solvents and high end co-polymers high resistance inks will have a ten dency to body during a run

Know What you are using and why

"I only buy inks based on cost"

"I only Buy High Resistant inks"

"I do not want to be testing every run"

* Remember, the enemy is down time, waist and poor quality

What adjustments can
be made on press

Some tools needed

Viscosity Viscosity (Zon) Cups
PH PH meter
Color Adjustments Formula
Increase rewetting A method of accurately weighing,
measuring and Proofing
Maintain foam A method of accurately weighing,
measuring and Proofing
Increase color strength A method of accurately weighing,
measuring and Proofing
Decrease color strength A method of accurately weighing,
measuring and Proofing
Improve leveling and hold-out A method of accurately weighing,
measuring and Proofing