Contents How can the Anilox improve your quality Anilox Parameters 1 How can the Anilox improve your quality Anilox Parameters Screen Selection Anilox volume & ink release Best engravings for Fixed Palette Care and maintenance

How can the Anilox improve your print quality?

Selecting the right specification will improve: White opacity Uniformity of solids Print definition and clarity Ink laydown Gloss levels in varnish applications

Anilox Parameters

Engraving angle The spacial orientation of cells in subsequent rows of engraving in relation to the horizontal axis of the Anilox roll. The placement of the cells determines the cell shape and more precisely, the orientation of the cell opening. When the cell opening is wider along the rotational axis, ink can flow out easier. When the cell opening is narrower, there is less turbulence in the ink flow and less pinholing.

Engraving angles 60° 45° 30° 75° 70° 30 and 60 degree angle engravings have 15.5% more cells per square inch than 45 degree angle engravings Angle determines the cell shape: hexagonal or diamond shape These additional cells provide a more uniform distribution of ink to the plates. In addition, there are no large land areas (which do not hold ink) between the cells as in the 45. Because of these large land areas, ink has farther to flow to fill the gaps for solid coverages. The engraving angle is important because the placement of the cells determines the cell shape and more precisely, the orientation of the cell opening. When the cell opening is wider along the rotational axis, ink can flow out easier. When the cell opening is narrower along the rotation, there is less turbulence in the ink flow and less pinholing results in the print. The other important aspect of engraving angle pertains to the efficiency of the cell placement. In a 45 degree pattern, excess wall naturally occurs rotationally between the cells. This wall takes up roll surface area that could otherwise be used for carrying ink.

Moire pattern To avoid moiré: The difference between the screen angles of cyan, magenta and black should be 30°. The screen angle of yellow must differ by 15° from cyan or black The screen angle must be 7.5° away from the Anilox screen angle. The Anilox screen to plate ratio must be at least 5.5 ie. 100LPI plate/ 550LPI Anilox Most common flexo angles Most common offset angles

Line count Refers to the number of cells in a lineal inch/ centimetre as measured along the engraving angle (because that is where the cells line up in closest proximity to each other). Cell diameter plus wall thickness equals the Pitch. By dividing 25,400 (the number of microns per inch) by the pitch, the result is the line count (the number of cells per inch). Line screen is chosen in direct correlation to anilox volume.

Line count affects print quality More cells means finer ink distribution More uniform coverage on solids Cleaner vignettes Easier drying The line count of an anilox roll is an important consideration. Line count determines the total number of ink dots that will be transferred to the plates. Higher line counts place more cells, closer together. This provides many benefits for the print quality. For example, coverage on solid areas is more uniform. Smaller ink dots dry quicker allowing for faster press speeds. Because they dry faster, smaller dots tend to produce less dot gain. This allows for sharper edges on linework, and better image clarity for process jobs.

Finer ink distribution Printed with 250LPI Printed with 500LPI

Sharper edges 400LPI 600LPI

Dirty Print

Preventing Dirty print / Dot bridging Fault Dot dipping The Anilox screen should be 6 times the plate screen Because line count affects ink distribution, it becomes a critical factor in the quality of the print job, particularly when printing process jobs. Smaller dots are closer together and produce more uniform solids. The down side of higher line counts is that as the cell size is reduced, it becomes more challenging to deliver adequate cell volume to achieve desired colour densities and opacities

To prevent dot bridging the Anilox screen must be 5-6 times the plate screen Dot supported by several cells Effect of the dot size of a 200LPI Plate on a 900LPI /360LPC Anilox 25% 10% Dot dips into the cell 2% 5%

Cell volume volume refers to the carrying capacity of the cells in a square inch or square centimetre of roll surface area Cell opening Cell depth Remember you can use a lower volume anilox roll with a 60° cell because more cells fit into a square inch in this configuration. However, a cell with too small of a volume will cause ink to dry before it can be transferred, unless there are sufficient drying inhibitors used. The goal is to specify an anilox roll that will deliver the colour strength and densities needed with the thinnest ink film possible.

We must differentiate Anilox volume which is the carrying capacity of the Anilox from the transferred volume.

Factors that effect transfer Ink flow characteristics: viscosity, pigment load, and pH Doctoring method: doctor blade, rubber nip roll, closed chamber system Characteristics of the doctoring system: durometer of the rubber roll, thickness and type of blade material, nip or doctor blade pressure Press speed Surface tension of the plates and substrate Absorption rate of the substrate

One main factor that will affect the ink transfer from the anilox cells, it is the cells themselves. Cell shape and engraving geometry will affect the Anilox ink transfer properties.

Screen Selection & engraving types

In order to achieve the best print quality a good rule of thumb it’s to specify the Anilox roll to the highest line count possible providing the cell volume is adequate to get the desired colour density or coat weight.

60 degree hexagonal engraving

+ 15.5% more cells per square inch than 45 degree angle engravings 45 degrees diamond engraving 60 degrees hexagonal engraving + 15.5% more cells per square inch than 45 degree angle engravings

The 60 degrees hexagonal pattern became the industry standard

60 degree cell profile limitations: Conical shape restricts Ink release Prone to plugging Difficult to clean Enclosed cells can cause micro foaming

New extended cell design Ink Retention New extended cell design 60 deg. cell Up to 40% 10-15%

By increasing the cell volume without lowering the line count, the cell will be less efficient at releasing its volume and will retain more ink 30% retention 40-42% retention

New specifications can transfer on average 25% additional volume

Cell Shape & Ink Transfer In order to increase the Anilox line count without loss of ink coverage The cell shape must be changed to Improve ink transfer

The finer the line count, the better the print will be…… Providing we deliver the correct density

maxflo Cell profiles is more efficient at transferring the ink, achieving up to 30% more compared to conventional engravings Allows the use of higher line counts without the loss of volume

Fixed palette Printing Fixed colour palette printing requires precise registration, consistent dots and minimal dot gain In order to achieve this the Anilox consistency and efficiency at transferring the ink is critical.

Finer plate technology requires finer Anilox roll 60 degrees cell unsuitable due to poor release Channel specifications could cause problems such as dot dipping/ bridging

Proflo Engraving hybrid of 60 degree and MaxFlo

Printed using same ink and print conditions ProFlo Main Features & Benefits Printed using same ink and print conditions   1000 LPI 3.8cm3/m2 Anilox 60 deg. hex 1300LPI x 3.5cm3/m2 ProFlo C 1.15 1.35 M 1.25 1.4 Y 0.90 1.0 K 1.50 ProFlo delivers up to 10% more ink than 60deg engravings This allows the use of higher line counts without loss of colour densities Higher ink densities are achieved. Increasing the density throughout the full tonal range widens the available range of colours and increases the process colour gamut.

flexo offset ProFlo Now you can print that looks like EsKo Artwork HD Flexo Certified Vendor ProFlo for HD Flexo & ECG Provides an improved ink lay down that delivers higher contrast, extended tonal range and better image definition at ultra fine line counts . 60 degrees standard engraving ProFlo engraving Now you flexo can print that looks like offset

MaxFlo+

MaxFlo+ 3D image

How does it work? With closed-cell configuration air gets trapped causing foaming and uneven laydown of ink to the plate Foaming will be seen as pin holing in the print Maxflo+ is a channel engraving Improves ink flow eliminating aeration of ink Provides a more consistent, smoother and pin-hole free lay down of ink

Main benefits: No UV spitting Improved colour consistency Higher print definition Increased ink transfer of up to 30% compared to conventional engravings Cleaner vignettes & rich solids with one single Anilox Designed to run at high press speeds (+ 600m/min )  Reduction of make ready times, as fewer changeovers are necessary Fast and easy clean-up Recommended for Fixed Palette printing Ink laydown with MaxFlo+ and hexagonal engraving

Achieving adequate colour density and reproducing it on each successive run is key to the success of Fixed Palette.

VOLUME CONTROL Anilox rollers must be regularly monitored and their volume checked to ensure print consistency

ANILOX MAINTENANCE

Anilox Cleaning recommendations As a standard practice, rollers should be always cleaned as soon as the roller is taken out of service with an adequate Anilox cleaner. After manual cleaning, engravings should be viewed under high-power magnification to ensure they are clean. If the cells are not plugged with ink, they should not be cleaned with off-press systems. Never leave the ink to dry in the cells. It will makes it increasingly difficult to remove. This can be especially true with water-based inks. Keep the rollers turning whenever there is ink in the system. Most presses are equipped with idling motors to accomplish this. If yours is not, it may be worth the investment for you. Protect your Anilox rollers against air drafts. Keep them covered. Regular cleaning will  make cleaning easier and faster

Anilox Sleeve Maintenance Avoid using aggressive chemicals or caustics as the aluminium cladding is susceptible to corrosion Keep the inner composite always dry and free from any chemicals Ensure inner bores are clean and free from dried ink Avoid rocking the sleeves up and down during mounting Preferably Store sleeves vertically

Thank You.