As businesses face increasing demands for flexible packaging and sustainable solutions, traditional printing methods often fall short, struggling with cost efficiency and print quality. Companies need a solution that can handle complex designs and varied substrates without breaking the bank or compromising on performance.
Flexographic printing presents a modern solution to these challenges. By utilizing advanced anilox roller technology and eco-friendly inks, this high-speed method excels in delivering high-quality results on materials such as film, foil, and corrugated packaging.
In this blog, we will look into what flexographic printing is, how it works, and explore its various use cases. We’ll also cover the advantages and disadvantages of flexography and discuss the different types available.
What is flexographic printing?
Flexographic printing, also known as flexo printing or flexography, is a modern form of letterpress printing that uses flexible rubber or photopolymer plates to create images that are then transferred onto a wide range of surfaces.
It is capable of printing up to 2000 linear feet per minute, it delivers high-resolution results on various substrates, including:
- Paper
- Plastic films
- Corrugated cardboard
- Non-woven fabrics
- Metallic surfaces
- Multilayered film composites
History of flexography
Flexographic printing originated about 170 years ago with Bibby, Baron, and Sons in England.
They developed an early rotary press using rubber plates and a homemade ink made from dyes dissolved in water and mixed with sugar. Initially based on letterpress and rubber stamp technology, early methods had limitations that often resulted in imprecise prints.
Fun fact: The flexographic printing machine market is set to soar with an impressive growth rate of 11.3% each year from 2021 to 2026.
Modern advancement
How does flexo printing work?
Flexo printing is a key technology in the world of packaging and labeling, known for its versatility and efficiency. Here’s an in-depth look at the process, its evolution, and its modern applications.
Here is how it works:
Step 1: Image preparation
Flexographic printing begins with precise image preparation. Clients provide artwork that must be optimized for the flexographic press. Because the printing plates are fixed once made, the artwork must be flawless.
Images designed for flat surfaces need adjustments for accurate reproduction on cylindrical surfaces to ensure high-quality prints.
Related: Flexo printing vs Offset printing
Step 2: Flexible plate making
Creating flexographic plates involves several techniques:
- Metallic plate etching/rubber plates: This traditional method etches the image onto a metal plate, which is then used to create a flexible polymer mold. Although effective, this technique is costly and complex, making it less common today.
- Photo etching/photopolymer plates: The most widely used method today, it involves transferring images from a photo negative to a light-sensitive polymer plate using ultraviolet light. The plate is then developed by washing away the unexposed areas.
- Digital platemaking: This modern approach uses a computer-controlled laser to etch the image directly onto a photopolymer plate, eliminating the need for film negatives and speeding up production.
Step 3: Mounting
After plate making, the plates are mounted onto the press cylinders. Each color in the design requires a separate plate. Accurate alignment of these plates is essential to ensure proper color registration and avoid misalignment during printing.
Step 4: Printing process
In flexible relief printing, a series of rollers work together to transfer ink to the substrate:
- Fountain roller: Transfers ink from an ink pan to the anilox roller.
- Anilox roller: Delivers a uniform layer of ink to the flexible printing plate.
- Plate cylinder: Applies ink to the substrate as it passes between the plate cylinder and the impression cylinder.
- Impression cylinder: Applies pressure to transfer the ink from the plate to the substrate.
Flexo presses come in various types:
- Stack press: Features vertically stacked printing decks, allowing for printing on both sides of the substrate.
- Central impression (CI) press: Uses a large central impression cylinder for excellent color registration.
- In-line press: Arranges printing decks in a straight line, ideal for handling heavier substrates.
Step 5: Substrates and inks
Flexible relief printing can be applied to various substrates:
- Papers: Both coated and uncoated.
- Carton boards: Commonly used for packaging.
- Plastics: Various films such as LDPE, PP, BOPP, and PET.
- Laminates: Multi-layered materials providing added protection.
Inks used in flexo printing include:
- Water-based inks: Suitable for corrugated packaging.
- Solvent-based inks: Ideal for plastics and industrial films.
- Energy-curable inks: Cured with UV light or electron beam (EB) systems, used for food packaging.
Step 6: Prepress, press setup, and post-press
- Prepress: Ensures that artwork and images are ready for printing. Adjustments are made to address potential issues such as dot gain and image elongation to prevent defects.
- Automation and software: Modern prepress software, like Esko’s tools, automates and optimizes the preparation process, reducing errors and accelerating turnaround times.
- Post-press and finishing: In-line presses often include finishing processes such as die-cutting, cold foil stamping, and varnishing. Additional converting equipment, including slitting machines, folders, and die-cutters, transforms printed rolls into final packaging formats like cartons, boxes, and pouches.
What is flexo printing used for?
Flexo printing is a versatile technology widely used across various industries due to its ability to handle different inks and substrates efficiently.
This printing method is particularly effective in producing high-quality, high-volume outputs for a range of products, including:
- Self-adhesive labels: Ideal for a variety of labeling needs, offering flexibility and durability.
- Cut & stack labels: Commonly used for packaging consumer goods, ensuring reliability and clarity.
- Food and beverage packaging: Essential for complying with stringent safety and quality regulations, flexographic printing provides precise and compliant packaging solutions.
- Plastic carrier bags: Suitable for producing robust and functional bags, making it a popular choice for high-volume production.
Flexible relief printing technology stands out for its speed and accuracy, making it a preferred option in industries such as pharmaceuticals and food and beverage.
The technology’s capability to print on diverse materials, including foils, cellophane, paperboards, and plastics, supports its widespread use and effectiveness in meeting various industry standards.
Advantages of flexo printing
- Flexographic printing is highly versatile, capable of printing on a variety of materials such as plastics, films, and paper. This makes it an ideal choice for creating high-quality packaging and labels.
- It is a cost-effective solution, with lower initial expenses for both printing plates and presses. The reusable nature of the flexible plates also helps to reduce overall costs and minimize waste.
- The technology allows for high-quality image reproduction. Flexographic plates can be precisely etched, resulting in sharp, detailed prints.
- It supports a wide range of colors, making it suitable for full-color printing projects.
- Flexographic presses operate at high speeds, enabling the rapid production of large volumes of labels and packaging.
- The process accommodates various materials and substrates, helping businesses comply with national and international regulations for packaging and labeling.
- It generates minimal waste, conserving materials and resources.
- Consistency is a key advantage, as flexographic printing delivers reliable and high-quality results throughout extensive production runs.
- The technology offers a strong return on investment. It balances low operational costs with the ability to produce high-quality, large-scale prints.
Disadvantages of flexography
- High initial setup costs due to the need for custom-made plates for each design.
- Not cost-effective for short print runs or jobs that frequently change designs.
- Struggles with producing a wide range of colors and intricate details, especially with fine or complex designs.
- Significant setup time, particularly when multiple plates are required, which can slow down production.
- Some processes involve solvent-based inks and cleaning agents, which may harm the environment.
Environmental impact of flexography
Aniline printing , like other printing methods, has environmental implications. The process consumes considerable energy and generates waste, including unused inks, discarded printing plates, and excess packaging.
Additionally, the chemicals used in flexographic printing can pose risks to both the environment and human health. Water usage is another concern, as substantial amounts are required for cleaning the printing plates and equipment.
Mitigation strategies:
- Use eco-friendly inks and solvents to reduce environmental impact.
- Implement recycling programs to manage waste effectively.
- Adopt energy-efficient equipment and practices to lower energy consumption.
- Employ water conservation techniques to minimize water usage.
Technology advancement
The future of flexo printing looks bright with exciting advancements on the horizon. As consumer demand for packaged goods grows, the technology is evolving rapidly to keep up. New flexographic presses are being developed to enhance automation, reduce labor requirements, and increase efficiency.
These advancements also focus on environmental sustainability. Modern presses now use eco-friendly materials and processes, aiming to cut down on waste and support greener packaging solutions.
Flexographic printing is benefiting from enhanced color accuracy thanks to Extended Color Gamut systems. These systems ensure consistent and precise color reproduction, even when combined with digital and offset printing methods.
Hybrid flexo/inkjet systems are another innovative development. These presses integrate inkjet technology to add full-color variable data to flexo-printed materials. This capability allows for better tracking, authentication, and interactive features on packaging.
Manufacturers now offer a range of options, including traditional flexo presses, hybrid systems, and digital presses. This variety provides businesses with flexible solutions to meet their specific needs.
Digital Flexography
Digital flexography combines digital precision with flexography’s efficiency, creating a hybrid approach that enhances setup speed, adaptability, and print quality. By digitally preparing images, it bypasses traditional film negatives, directly transferring designs to plates through a computer-to-plate system.
This method minimizes time and cost associated with plate creation while allowing high-quality results suited to fast-paced production environments.
Conclusion
In summary, flexographic printing provides an efficient and cost-effective way to print on materials such as paper, plastic, and film. Its capability to deliver high-quality, sharp prints at a lower cost makes it a preferred choice for packaging and labels.
Although it may not offer the same versatility as digital printing, flexo printing remains a crucial method in the industry, consistently producing reliable results.
Looking for customized printing solutions? Contact Print To Brand today to discuss how our custom printing options can be tailored to fit your specific needs.
