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Flexographic Printing

What is Flexographic Printing? Ultimate Guide

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The term flexographic printing is a term that is used more often in the printing industry. Because of its numerous features and applications, people want to know more about what flexography is and its uses in the market. 

“Flexographic printing is a contemporary process of printing that uses flexible relief plates on a rotary. It is commonly used for printing in large-scale industries, including packaging materials, labels, newspapers, and more.”

It is also workable on multiple materials, like plastic, paperboard, cardboard, vinyl, and other recycled materials. When there are so many more ways of systematic printing, this process has maintained its popularity and remained timeless because of its efficient printing, even with accurate die-cuts and intricate designs on any substrate. 

How Does it Work?

The process of flexographic printing is typical, with a photopolymer plate covered around a rotating cylinder for every colour with three other rollers. 

  • Fountain roller
  • Anilox roller
  • The plate cylinder
  • Impression cylinder 

The printing process begins with the involvement of a fountain roller that transports ink from an ink pan to an anilox roller, typically made of steel or ceramic. The anilox roller, acting as an ink-metering device, then conveys the ink to the plate cylinder. The ink is applied to the substrate as the paper moves between the plate cylinder and a polished metal impression cylinder. The impression cylinder imparts the necessary pressure to transfer the ink from the printing plate to the substrate.

In the flexographic process, the anilox roller is crucial in ensuring a consistent ink thickness on the flexible printing plate. Each anilox roller is equipped with finely engraved cells that determine its specific ink capacity. To further control ink application, an optional doctor blade is engaged to scrape the surface of the anilox roller, ensuring that only the ink contained in the engraved cells is delivered to the printing plate. 

This meticulous process contributes to the precision and quality of the final printed output.

The printing process can accommodate up to 10 colours. These colours vary according to the printing machine and could be water, solvent, oil, or UV ink. 

What is a Flexo Press?

A flexographic printing press comprises flexible plates and rollers, with traditional rubber flexo plates evolving into modern technology that wraps flexible photopolymer around a roller. Essentially, a flexo printer operates like a stamp, capable of printing at speeds of up to 2,000 feet per minute.

Commonly, the flexographic printing press is categorized into five types based on their configurations and design applications. These types are:

Stack Press

The vertically stacked decks enable the press to print on both sides of the material as it moves through the machine in a single pass. This is the most common configuration, also known as stack press. 

Central Impression (CI)

Central Impression

This type of flexo printing is popular due to its precise and high quality registration. Central impression presses feature printing decks encircling a single, large impression cylinder.

In-Line Press

In Line Press

In-line presses are often used for handling heavier substrates, such as corrugated cardboard. In this setup, the printing decks are aligned in a straight line suitable for broader-width printing. Due to its versatility, you have the option to add different finishing processes combined with Flexo, such as foil stamping, die cutting, and laminating.

Wide-Web Press

Wide Web Press

A wide-web press is specialized for printing large scales on wide rolls of substrate that exceed 18–20 inches in width. Commonly, these presses are best suited for flexible packaging and wide-format printing. The most versatile printing option, the vast web press, allows for handling various substrates and colours with the enablement of high-speed printing. 

Narrow-Web Press

Narrow Web Press

Narrow-web presses, initially developed for label printing, typically measure 10 inches wide or smaller. However, modern narrow-web presses, extending up to 20 inches wide, are employed for shorter runs of flexible packaging. This includes printing bottle wraps and smaller packets and pouches for products like teas, drink mixes, and single-serve packs.

Modern printing techniques encompass various methods catering to the consumer’s preferred requirements. Out of many, the most popular are:

  • Digital printing
  • Offset printing
  • Flexo printing
  • Gravure printing
  • Inkjet printing, etc

Offset Printing Vs Flexo Printing 

There is no debate on the finishing results of both printing processes; however, it is essential to know the differences to ensure you choose the right option for your project. 

The key differences include the following:

  • Flexography uses a group of rollers or rotary flexible plates instead of offset plates that print indirectly on the substrate. 
  • Offset printing is usually opposed to die-cutting, folding, and lamination being applied after the process. Whereas, flexography printing incorporates these processes with a single operation. 
  • Flexography printing is famous for its flexibility and versatility. This includes printing on porous, non-porous, absorbent, or any material. However, offset printing is limited to printing on smooth or flat surfaces.
  • Both techniques are widely used, but offset printing can be extremely costly and time-consuming since it integrates special finishes after the completion of printing and does not require a single operation as compared to flexo. 

Advantages of Flexography

  • The reason that makes flexo printing the best option is that it allows the incorporation of special finishes within the process itself, like: 
  1. Embossing and Debossing
  2. Die-cutting
  3. Foil stamping
  4. Aqueous Coating;
  5. UV coating 
  • Flexographic printing is efficient enough to print images on a range of materials, like: 
  1. Plastics
  2. Acetate films 
  3. Kraft paper
  4. Corrugated boards
  5. Fabrics 
  6. Cellophane
  7. Metallic surfaces 

Its characteristic of printing on absorbent and non-absorbent materials does not restrict it from causing any disruption to the printing process. 

  • This process uses water-based inks, UV-curable inks, and solvent inks known for fast drying, making the printing more productive in terms of time savings and sustainability. 
  • To cater to audience preferences, this printing option can print loads of impressions and accommodate a range of cylinder repeat lengths. 
  • The contemporary advancements in flexo feature individual plates for each colour, which means it offers exceptionally high colour accuracy.
  • Its ability to incorporate various finishing options within a single process makes it a cost and time-saver.
  • The speed of flexo printing exceeds operations at up to 750 m/2000 ft per minute. 

What are Flexography Printing Plates?

Flexography Printing Plates

Flexo plates are the most crucial part of a flexographic printing machine. These plates were made of rubber; however, they have been upgraded and improvised into photopolymers due to their versatility and durability. These plates have a raised image or text that holds ink for transfer to the substrate. Mounted on the plate cylinder of a printing press, flexo plates are versatile and suitable for various substrates like paper and plastic. Advancements include digital flexo plates for enhanced precision and efficiency in the printing process.

Best Alternatives to Flexography Printing

The alternative options for Flexo usually depend on the desired outcomes and other factors that can effect the process. Some of the best alternatives to flexography printing include:

  1. Offset Printing

Offset printing is a widely used alternative for high-quality, large-volume printing. It is known for its ability to reproduce intricate details and vibrant colors on various substrates, including paper, cardboard, and metal.

  1. Digital Printing

Digital printing offers flexibility, speed, and customization. It is suitable for short runs and variable-data printing. Inkjet and laser printers are standard digital printing technologies.

  1. Gravure Printing

Gravure printing is often chosen for long print runs, especially in the packaging and publication industries. It provides high-quality prints and is capable of reproducing fine details.

  1. Screen Printing

Screen printing is versatile and can be used on various surfaces, including textiles, glass, and plastics. It’s commonly employed for signage, apparel, and decorative items.

  1. Lithography (Litho) Printing

Lithography is widely used for high-quality, large-scale printing, particularly in the commercial and packaging sectors. It’s known for its detailed images and consistent prints.

  1. Inkjet Printing

Inkjet printing is suitable for a wide range of materials, offering high-resolution prints. It is commonly used in industries like packaging, textiles, and signage.

  1. Letterpress Printing

Letterpress is a relief printing technique that creates a tactile impression on the printed material. While it’s less widely used than other methods, it is valued for its unique aesthetic.

The choice among these alternatives depends on factors such as the printing volume, substrate, image complexity, and the level of customization required. Each method has its strengths and weaknesses, making it essential to select the one that best fits the specific printing needs.

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About Stephen Fowler

About Stephen Fowler

Meet Stephen, our skilled writer at IBEX. With a degree in Packaging Sciences, Stephen brings expertise in simplifying every industry detail more efficiently. His years of experience in R&D and technical expertise have always been helpful for our audience. The best part about Stephen is that he has always provided consistent and valuable insights into the packaging industry, ensuring that our reader is always up to date with the latest practices.

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