Characteristics of Flexo Printing and Flexographic Presses

What is the difference between wide-web and narrow-web flexographic presses?

·A flexographic press is a web-fed rotary printing press. Flexographic presses with a printing width of less than 600 mm are generally referred to as narrow-web flexographic presses, while those with a printing width of more than 600 mm are referred to as wide-web flexographic presses.

How can flexographic presses be classified according to their press unit configurations?

·Flexographic presses can be classified into three main types according to the arrangement of their printing units: central-impression (CI) presses, stack-type presses, and inline presses.

1. Central-Impression (CI) Flexographic Press

In a central-impression flexographic press, all printing units share a single central impression cylinder (CI cylinder). The substrate is held against the impression cylinder while multiple colors are printed sequentially.

**Key features:

High registration accuracy

Wide range of suitable substrates

Short setup and adjustment time

Low material waste

Can be equipped with inline finishing processes

However, CI presses generally perform single-sided printing only.

2. Stack-Type Flexographic Press

A stack-type flexographic press uses printing units arranged in a vertical stacked configuration.

**Key features:

Compact footprint

Easy operation and maintenance of the printing units

Wide range of suitable substrates

Capable of double-sided printing

Can be equipped with inline bag making, cutting, laminating, and other post-press processes.

However, its multicolor registration accuracy is generally lower than that of CI presses, making it more suitable for printed products with standard or moderate quality requirements.

3. Inline Flexographic Press

In an inline flexographic press, the printing units are independent of one another and arranged horizontally in a straight line.

This configuration facilitates modular press-unit design and is suitable for printing on paper sheets, paperboard, corrugated board, and web-fed substrates. It can perform both single-sided and double-sided printing.

In China, inline flexographic presses are widely used in flexographic printing production.

How many types of inking systems are there in flexographic presses?

·A flexographic press generally consists of an unwinding section, printing section, drying section, and rewinding section, among other components.

Types of Inking Systems in Flexographic Printing

①Fountain Roller–Anilox Roller Inking System

* Low wear, resulting in a long service life of the anilox roller.

* May cause excessive ink transfer, while ink transfer can become uneven when using a small ink volume.

* Mainly used in mid-range and low-end flexographic presses.

②Anilox Roller–Doctor Blade Inking System

*Can accommodate inks with a wide range of viscosities.

*Can be divided into a forward doctor-blade inking system and a reverse doctor-blade inking system.

③Fountain Roller–Anilox Roller–Doctor Blade Inking System

④Ink Chamber–Doctor Blade Inking System

The anilox roller is a key component for ensuring consistent ink transfer and ink distribution. Anilox rollers are generally available as chrome-plated metal anilox rollers and ceramic anilox rollers.