The flexographic printing process is considered one of the most versatile and widely used printing methods in the industry.
It is commonly employed for producing packaging materials, labels, newspapers, and other products that demand high-speed, large-volume printing.
Flexographic printing is known for its ability to print on a variety of substrates and is the preferred choice for cost-effective and efficient printing.
In this article, we'll provide a comprehensive overview of how the flexographic printing process works and its key stages.
Flexographic Printing Process: Steps and Overview
Flexographic printing is a versatile and widely used printing process that is commonly employed for producing packaging materials, labels, newspapers, and other products that require high-speed, large-volume printing.
Flexographic printing is known for its ability to print on a variety of substrates and is ideal for jobs where cost-effective, efficient printing is essential.
Here's a general overview of how flexographic printing is done:
Prepress PreparationDesign and Artwork
- The process begins with the creation of a digital design or artwork that is intended to be printed.
- This can be done using graphic design software like Adobe Illustrator or CorelDRAW.
- The digital design is transferred onto a flexographic printing plate.
- This plate is typically made of a flexible material, such as rubber or photopolymer, and serves as the printing surface for the press.
- The plate-making process involves exposing the plate to UV light through a film or digital image, which hardens or develops the areas to be printed.
Ink PreparationInk Mixing
- Depending on the specific job requirements, ink is prepared by mixing the necessary pigments, solvents, and other additives.
- In flexography, inks can be water-based, solvent-based, or UV-curable, depending on the application.
Printing ProcessSubstrate Feed
- The substrate (material to be printed on), which can include paper, cardboard, plastic films, or other materials, is fed into the flexographic printing press.
- The ink is applied to the printing plate, typically using a roller system known as anilox rollers.
- Anilox rollers have engraved cells that control the amount of ink transferred to the plate.
- The inked plate comes into contact with the substrate.
PrintingThe substrate and plate pass through a series of rollers and cylinders that apply pressure, transferring the ink from the plate onto the substrate.
Drying and Curing
- For water-based inks, hot air dryers or infrared lamps are often used to evaporate the water content.
- Solvent-based inks rely on the evaporation of solvents to dry.
- UV-curable inks are cured instantly by exposing them to UV light. UV lamps are positioned at the end of the press to initiate the curing process.
After printing, additional finishing processes may be performed, such as laminating, die-cutting, slitting, or folding, depending on the specific requirements of the printed product.
Throughout the printing process, operators monitor the print quality to ensure that colors, registration, and overall print appearance meet the desired standards.
Flexographic printing often generates waste in the form of unused substrate and trimmings.
The printed materials are typically wound onto rolls or sheets, inspected for defects, and then packaged for shipping or further processing.
Types of flexography printing
- Water-based flexo inks use water as the solvent, making them environmentally friendly with low volatile organic compounds (VOCs).
- They are commonly used in food packaging and other applications requiring non-toxic inks.
- Solvent-based flexo inks use organic solvents for pigment dispersion.
- They offer excellent adhesion and are suitable for applications like outdoor signage and industrial packaging.
- Similar to UV flexo printing, UV LED flexo printing uses light-emitting diodes (LEDs) for curing UV inks.
- It offers energy efficiency and precise curing control, making it suitable for various applications.