Flexography

Flexography

Tech Sleeves is a start-up operating in the flexographic industry. It is a separate division under the company AllFlexo BV. At Tech Sleeves, we are dedicated towards serving the global flexographic printing industry with Plate sleeves and Bridges/adapters. Founded almost 3 years ago by the Color Control Group, we have now flourished worldwide. We have a devoted network setup in various countries to understand and satisfy the needs of our customers locally.

 

What is flexographic printing?

Flexography is a type of a rotary in-line printing method. Derived from the Latin word “Flexus”, literally translated as “bending”, flexo printing is used to print on any flexible material. These flexible materials can vary from plastics, paper, metallic films to cellophane. Printing variable repeat lengths, using a broad range of inks and a wide variety of substrates is possible with flexo printing.
 
Flexography started as a rubber stamp printing method. In 1980, Bibby, Baron and Sons built the first patented flexo press in Liverpool. Since then, a lot of innovations have revolutionized the flexographic printing industry. Today, almost 60% of the printed packaging industry comprises of flexo printing. Modern flexographic printing presses also have a lamination and die cutting process integrated in them. This is done to protect the product’s final shape and size. Due to the rising demand for flexible packaging, flexo industry is growing rapidly.

 

What is flexographic printing used for?

Flexo printing products

Flexographic printing products

 

It is challenging to imagine a day without crossing flexographic printing products. Around you, you will find many products, be it grocery or office-supplies, which are packaged with flexo printing. Some of the examples of flexographic printing products are:

  • Business forms;
  • Packaging for food and drinking products;
  • Flexible Packaging;
  • Labels;
  • Envelopes;
  • Wallpaper;
  • Gift wrapping paper;
  • Newspapers;
  • Textiles;
  • Folding carton;
  • Foil, etc.

 

How is flexography different from other printing methods?

With advancement in technology, flexo presses have become the fastest growing printing process in the world. Let us understand the difference between flexo printing and other different printing methods:

Offset Lithography vs Flexography

In offset printing, inked image is transferred from a plate to an intermediate carrier and finally on to a substrate. Briefly, the image is not transferred directly from a plate to a substrate. Whereas, image is directly transferred to a substrate in flexo printing. Other than the process difference, the types of plate, ink and substrate used is also different. Flexo uses flexible printing plate allowing it to be used on almost any substrate with a flexible surface. And offset printing is limited only to a flat surface.
 
The main advantages of flexography over offset are:

 

  • High speed production
  • Cost-effective for large orders
  • Uses rolls of substrates, which allows large orders to be printed without interruptions.

Rotogravure vs Flexographic printing

In gravure printing, image is transferred on to a substrate by using a metal plate. This metal plate has a sunken (depressed) surface, which is bathed in ink and wiped clean before application. Whereas, flexographic printing usually uses a photopolymer (rubber) plate which has a raised image.
 
The main advantages of flexography over gravure are:

 

  • Extremely high speed printing
  • Diverse and versatile applications
  • Lower costs for short or medium print runs.

Digital vs Flexo printing

In digital printing, physical printing plates are not needed to create the image. Instead, it uses a concept that attracts ink on the substrate with the help of positive and negative electrical charges. Additionally, it is still a new method and thus, lacks the advancements that other printing methods have made.
 
The main advantages of flexography over digital are:

 

  • High quality results
  • Extremely high speed printing
  • Cost-effective for longer runs.

  • What are the advantages of flexography?

    All printing processes have their own unique advantages. Nevertheless, flexo printing process is still the leading technology in the printing industry. It is considered to be the best method for long-term ROI for medium to long print runs. Let us look at some of the main advantages of flexo printing:

     

      • Versatility: Flexo not only accommodates a wide variety of substrates, but it also allows the use of various types of inks. Solvent based ink, water based ink or U.V curable ink can be used depending on the type of substrate being used. Any porous or non-porous flexible material can be used, making flexo printing extremely versatile.

     

      • Quick production process: Flexo press can provide an average speed of 300 meters per minute. This quickly compensates the moderate amount of time spent on set-up. And this set-up time is constantly reducing with developments in the industry, to even make shorter runs economical.

     

      • Automated process: Laminating, die cutting, sheeting are processes that are now integrated up to the finishing stage. Once they are set up, the process is fast, making flexography a desirable choice for printing companies.

     

      • Less maintenance: Flexographic printing uses machines and equipment that need very less maintenance. This reduces the maintenance cost, making it a very economical alternative.

     

      • Low-cost consumables: The cost of consumables like flexographic inks, packaging materials, etc. are comparatively low. And even though the initial cost of plate is a little high, the price per unit is consistently low. This makes flexographic printing process the most cost-efficient solution, providing quick return on investment.

     

      • Color palette: Flexography usually uses the 4 process colours (CMYK): Cyan, Magenta, Yellow and Black. But a flexo press can also accommodate 10 colors to create the extended colour gamut. With this, it is easy to print pantone colours at a commercial scale.
      • Environment friendly: The use of water based inks, recycled inks, and water washable flexo plates can make flexographic printing eco-friendly. The impact on the environment is reduced as less toxins and solvents are used in the production process. And this also makes the flexographic printing process, user friendly.

    What is flexographic printing process?

    The flexo printing process actually begins with an idea/design of the packaging. But at the shop floor in a printing company, the workflow is divided into 2 phases: prepress and printing.
     
    Prepress:
     
    Prepress as the name suggests, is everything that happens before the press (printing department). The prepress department prepares everything needed to run the press. The process begins with plate making, where the design is transferred to create a stamp, known as plate. Printing companies can either make the plates in-house or approach trade shops that deliver plates with design on them. Several plates are created to print one design as each plate corresponds to one particular colour. The print of these different coloured plates overlay on each other to create various shades and complete the design.

    Prepress

    Once the plates are ready, they need to be mounted on a printing cylinder or a plate sleeve. The plate sleeve is covered with mounting tape and the printing plate is then placed on it. It is very crucial that the plates are mounted accurately. Inaccurate plate positioning will lead to undesirable print results. Even a slight difference in the placement of any one coloured plate will affect the final print quality. A mounting machine helps the operator to place the plate on the sleeve with precision. Many different types of mounting machines ranging from manual, semi-automatic to fully automatic are available in the market.
     
    Flexographic ink is prepared in the ink-kitchen, where sometimes process colours are mixed to create spot colours. Process colours are CMYK. And spot colours are independent mixes of process colours to create an almost pantone shade. The colours to be used for printing depends on the customer’s requirements.
     
    The press-ready sleeves, prepared ink from the ink-kitchen, doctor blades, anilox rolls, etc. are then carried to the printing department.
     
    Printing:
     
    This section explains “How flexographic printing works?” The printing department is where the actual printing takes place. There are several printing stations in one press, depending on the number of colours to be used for printing. Each printing station prints one corresponding colour. The substrate is passed through multiple printing stations. The actual design is achieved when different colours are overlaid to get various shades. Let us understand the printing technique used in the flexographic industry:

    Flexography Diagram

      • The typical process begins with the anilox roller transferring ink from the ink pan to the plate.

     

      • The doctor blade measures the ink to transfer an even amount of ink on the plate. It also ensures uniform distribution of ink.

     

      • The desired substrate is passed between the impression cylinder and the plate cylinder.

     

      • The impression cylinder pushes the substrate towards the rotating cylinders. This allows the rotating cylinder to kiss the surface of the substrate. Thereby, the design on the plate is transferred on to the substrate.

     

      • The fresh printed substrate is then passed through a dryer to dry the ink.

     

      • Once the ink has dried, the substrate continues its journey to other printing stations.

     

      • When all the colours have been printed, the substrate is finally processed through an additional dryer. This is done to remove any solvent or water residues.

     

    Other processes such as laminating, die cutting, sheeting, etc. are then carried out as required. The final product is at last ready to be fed through a cutter or rewound as needed.

    What are some of the flexographic products that we offer?

    As a part of the Color Control Group, Tech Sleeves specializes in manufacturing printing sleeves and bridges/adapters. The consumables division of AllFlexo, offers revolutionary water washable printing plates and high quality doctor blades branded as Tech Blades. Our sister company, AV Flexologic, is a global leader providing high-end, high-precision and high-quality flexo mounting machines.
     
    With each company specializing in its own domain, we aim to offer a complete package of world class flexographic print solutions.

     

    Would you like to know more about our flexographic print solutions?

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