Flexographic printing technology in curved surface offset printing machines

Flexographic printing technology originated in 1853 when Kingsley from the United States obtained a patent for rubber printing plates.

In the 1860s, a rudimentary printing press was developed, which utilized aniline dye ink and elastic rubber as the printing plate material—this early method was known as aniline printing or rubber plate printing.

Aniline dye ink is known for its vibrant color, but it is susceptible to fading and has toxic properties. As a result, it has largely been replaced by more stable dyes or pigments that offer superior lightfastness and safety.

In 1952, during the 14th Packaging and Printing Conference, the term "aniline printing" was officially replaced by "flexographic printing," marking a significant milestone in the evolution of the technology.

Over the past few decades, flexographic printing has seen substantial advancements in four key areas: printing plates, inks, ink delivery systems, and printing presses. These developments have established flexography as a major printing process, alongside traditional methods such as letterpress printing, offset printing, and gravure printing.

The curved surface offset printing machine employs elastic letterpress image printing plates. These plates are mounted onto the printing cylinder. The ink is transferred to the printing plate via a metal anilox roller engraved with fine ink cells. The ink transfer volume is precisely controlled by either an ink transfer roller or an ink doctor blade.

The ink transfer mechanism in flexographic printing on curved surface offset printing machines is relatively straightforward. Low-viscosity, highly fluid ink fills the tiny ink cells of the anilox roller. Excess ink is removed by the doctor blade, leaving ink only within the engraved cells. This ink is then transferred to the raised image areas of the flexographic printing plate. When the inked area of the plate comes into contact with the printing substrate, a "lip mark" is formed. A gentle pressing action completes the ink transfer process.

In today's highly competitive market environment, improving printing quality with minimal investment has become a priority for industry players. Flexographic printing has entered a new phase of development. This article will also explore the differences between various types of printing plates and introduce the flexographic plates used in isgo curved surface offset printing machines.