FLEXOGRAPHIC PRINTING INKS
Flexo printing is a method involved in different kinds of printing press like;
• In-Line Press
• Common Impression Press
• Stack Press
Process of Flexo Printing:
The material to be printed passes between normal cylinder and a metal impression cylinder backs up printing when it connects to the printing plate. Be careful for the gap between plate cylinder and the polished metal impression cylinder.
Unwind and unroll process:
In the first section substrates are supplied from rolls or web must be controlled by any tool or person to stay away from wrinkles until in-feed in the printing machine.
Printing process:
Most crucial section of a press uses only one anilox roll, fountain roll, plate cylinder even only one color by default. Printing press can have two or more stations; one station for one color.
Drying process:
In this section, hot air uses by press to dry the ink used in the printing. Dryers are placed between different printing units so that each plate gets dry until another plate come.
Rewind process:
After completing overall printing process cycle will start for roll-to-roll printing.
Operational tools and equipments uses in Flexo Printing:
1. Anilox Roller: Anilox Roller transfers inks to the printing plates mounted between plate cylinders and metal impression cylinder. It makes roller prefix for ink generation and ink control to provide a fixed thickness.
2. Fountain Roller: Fountain roller also called metering roller are responsible to serve the ink from ink pan to the Anilox Roller.
3. Plate Cylinder: It holds flexible rubber like plate material and magnets and straps hold printing plate against it.
4. Impression Cylinder: It supplies pressure to plate cylinder so that printing image will be transferred to the substrate of the printing press.
5. Flexo Plate: Acts as the image carrier, the most popular image carriers, include elastomer sleeves and photopolymer plates, However it is important to keep in mind that there are other flexo image carriers
- Elastomer covered standard print cylinders
- Load-n-Lok Air Sleeve Technology
- Elastomer plates
- Photopolymer sleeves
6. Doctor Blade: Nowadays it is made of polymer materials with variety of edges and fragments the anilox roll to confirm that ink amount available in the engraved cells only delivered. There is also availability of printing press uses doctor blade of steel material.
7. Printing Inks: 5 major types of inks are used in the flexo printing; solvent based inks, electron beam curing inks, ultraviolet curing inks, chemically curing inks, water inks. It is controlled by the inking unit may be fountain roll unit or doctor blade sometime. Water based ink should be avoid if its size is below of 5 µm because it generates problems during recycle. Printing on a wide variety of substrate material with high speed makes billions of impression in the favor of flexo printing.