CI flexo press
A CI flexo press (central impression) is a type of flexographic printing press where all printing decks are arranged around a single, large-diameter impression cylinder. This design ensures that the substrate is held firmly against the common cylinder, eliminating stretching and ensuring perfect color-to-color register, even at speeds exceeding 500 m/min.
The primary advantage of the CI press is its superior registration accuracy, typically within ±0.05 mm, because the substrate does not wander between print stations. This makes it the go-to choice for printing on extensible films like polyethylene, polypropylene, and polyester used in flexible packaging, shrink sleeves, and stand-up pouches.
High Speed Flexo Printing Machine - Stack Flexo Flexo Printing Machine
Construction features include a massive central drum with a chrome or ceramic coating, water-cooled or heated to control substrate temperature. Each color deck contains an anilox roller, doctor blade, plate cylinder, and a dryer nozzle that directs hot air or UV light onto the printed web before it reaches the next deck.
The drying system on a CI press is critical because the web travels around the drum and must be dried between each color to prevent offsetting. High-efficiency hot air dryers with adjustable temperature and airflow are standard, while UV LED options are increasingly available for energy savings and low heat emission.
Maintenance of a CI press focuses on the central drum surface, which must be kept perfectly clean and free of scratches. Any damage to the drum will affect print quality across all colors. Regular inspection of the drum's concentricity and bearing condition is essential. Additionally, each deck's anilox and plate cylinders require periodic cleaning and replacement.
CI flexo presses are available in narrow (up to 600mm), mid (up to 1000mm), and wide web (up to 2800mm) versions. They are often equipped with automated features such as robotic plate loading, automatic viscosity control, and inline lamination stations, making them highly productive for long runs of premium packaging where consistency is paramount.
