Central Impression Drum (CI Drum)

Description of Central Impression Drum
A central impression drum (CI Drum) is a large, central cylinder in a CI Flexo Press around which multiple printing stations are arranged. Its primary function is to support and wrap the substrate (like paper or film) tightly, maintaining consistent tension and providing a stable surface for each color station to press against, resulting in precise color registration.

How Central Impression Drum Work
Substrate support: The substrate is wrapped around the CI roller and held tightly against it by the tension from the rollers at each individual print station.
Consistent tension: As the substrate moves with the roller, it maintains a consistent tension and speed across all color stations.
Precise registration: Because each color station presses against the same large cylinder, the colors are applied in perfect alignment (registration), which is crucial for high-quality multi-color prints.
Printing process: As the substrate passes through each station, the printing plate on a plate cylinder presses against the substrate and the CI roller, transferring ink to create a one-color print.
Drying: Driers are often placed between the color stations to dry the ink before the next color is applied, preventing colors from smudging.

Central Impression Drum Specifications

How Central Impression Drum Ensures High-Quality Printing
Precise color registration: The central impression drum prevents substrate movement and misalignment between color applications, crucial for printing on flexible materials.
Superior print quality: Stable pressure from the central impression drum leads to sharper images.
Support for flexible substrates: Central impression presses are suitable for printing on delicate materials like paper, non-woven fabric, and various films.
High-speed production: The continuous web path enables high-speed printing for high-volume jobs