What is Flexographic Printing Technology

How does the flexographic printing works?

March 7, 2023

Flexography printing uses a soft, flexible resin plate.It can print on different materials at high-speed with round printing cylinder desing.It can apply to textiles, paper, metal, plastic, etc. Meanwhile, it has several advantages over other methods, such as lower costs and faster production rates, and the plates can be reused multiple times.

Are you searching for a cost-effective label flexo printing machine? Look no further - in this article, we'll discuss its history,benefits, and process of making a flexo printing plate.

DEFINITION OF FLEXOGRAPHIC PRINTING

Flexographic printing uses a flexible plate through the anilox roller for ink transfer to print. It is a relief printing process, also known as flexo printing. The graphic part of the flexible printing plate is raised. When printing, the anilox roller will evenly coat an ink layer of a certain thickness on the pattern part of the printing plate. Then, under the action of the printing cylinder pressure, the pattern part of the ink layer transfers to the surface of the substrate, forming a clear graphic and text. The ink-transforming structure of the flexographic press usually uses two rollers.

Flexo-printing takes its name from the fact that it utilizes a flexible relief plate. The "flexible" part of the name refers to how this plate can be constructed from various materials , while "relief" implies an image that will rise above the surface of the plate.

Flexo printing is widely used for large-volume jobs such as garment labels, newspapers, and magazines. This production method is much faster than other print methods like letterpress or offsets lithography, and its plates can be reused multiple times before they need replacement.

ORIGIN OF FLEXOGRAPHIC PRINTING

Bibby Barron and his sons in LPO, UK invented the first flexo printing machine in 1890.1900 or so, companies in Europe start to use aniline-oil-based inks and rubber printing plates.But FDA delared the aniline dyes were unsafe in the 1940s.Food packaging has seen a decline in printing sales.By the 1920s, Germany had become the primary producer of presses.and they became commonly referred to by their German name:"gummidruck," meaning rubber printing - which still bears today under this designation in modern German.

At the beginning of the 20th century, aniline printing became widely used in USA.Companies tried different names like "Lustro Printing" or "Transglo Printing" ,but failed. Even after 1949, when the FDA approved new inks, some food companies did not consider aniline printing. Packaging professionals decided that aniline printing was not something they would consider. It needed to change its name from Lustro Printing to something entirely new.

Franklin Moss was then the founder and president of Mosstype Corporation. He asked readers of The Mosstyper what their preferred printing process was.More than 200 names have been collected. Mosstyper readers unanimously voted for "flexographic processing" after narrowing their choices to"permatone," or "rotopake." Finally, "flexography processing" gained the most votes.

Flexography offers many advantages over other printing methods. It's faster and more economical than traditional methods, plus its plates can be reused multiple times. It makes flexography the perfect solution for applications such as food packaging, newspapers,magazines, and labels.

Flexography was once only capable of printing on flat surfaces, but technological advances now enable it to be applied on curved surfaces. It has dramatically expanded its potential applications. Are you searching for a cost-effective label printing solution or need an expeditious and dependable printing process for food packaging? Flexography printing is an excellent option to consider.

WHY FLEXO PRINTING

1) PRINT OF HIGH QUALITY

Flexography can reliably produce high-quality images on a range of substrates without special coatings, thus reducing unit cost compared to other print options that may only support specific substrates. It makes flexography the superior print option since it has no limited substrate range.

2) HIGH-SPEED PRODUCTION

Flexo printing is fast. In the past, the average speed for a Flexo press used for packaging printing was 150 to 300 feet per minute (FPM). Modern Flexo presses can print 600 FPM at an average speed - providing businesses with significant advantages when they invest in new equipment. Furthermore, rotary printing heads enable continuous patterns to be printed, which allows printers to complete complex designs within one print run.

3) EXTREMELY VARIABLE PROCESS FOR PRINTING

Flexo printing is used in various industries, such as textile printing, packaging printing,and label printing. Due to their adaptability, presses can be tailored to fit different orders -providing print businesses with an edge over the competition by diversifying their operations and staying ahead.

4) ECONOMICAL FOR MEDIUM & HIGH-VOLUME PRODUCTION

Digital printing technology has made great strides but remains expensive and slow for large print runs. Flexo printing gives the best option for users requiring large printing works -particularly label industries - where costs can often be competitive with Digital, even on shorter runs.

5) One-Off Fees for Plates

While some critics may point out the difficulty and expense of making print plates for each flexographic print run, this can be seen in a different light. You can use your plate however often you like without incurring extra charges once made; the lower your print run, the cheaper per unit costs will be. Flexo plates have longevity if adequately maintained; repeat orders can be printed without overhead if taken care of properly. It has an advantage over digital printing due to the setup time and design work involved, and the lower volume of runs.

6) INLINE CONVERTING FLEXIBILITY

Modern flexo presses boast an inline conversion capacity that significantly reduces cycle time.Most print runs can be completed in one pass, and other inline processes like silk screening, hotfoil or cold foil stamping, variable data print (lamination), booklet inserting RFID insert, multilayer printing reverse side printing variable data printing primers coatings or adhesives can all be done on-site to further reduce overall finishing times.

7) PRINT ON DIFFERENT MATERIALS

Flexographic printing machines can print on various substrates, such as paper, textiles, labels, boards, foil, plastic film, cellophane, and recycled materials.

8) EXPLORE DIFFERENT TYPES AND DRYING SYSTEMS

Because of the flexo printing merits, inks and oven systems became more complex and capable. Modern presses can use both solvent-based and water-based inks.Efficient drying methods—using IR, UV, or air heaters--improve web speed while decreasing energy consumption and saving on ink usage. Plus, due to the easy mixing capabilities of modern inks, printers now have access to an unlimited range of colors to create precise formulae that can apply across multiple substrates, such as company branding colors on labels, food packaging, or textiles.

9) EASY TO USE & MAINTAIN

One argument in favor of digital printing is its speedy setup time. Flexographic presses used to take a long time to set up. However, they have been revolutionized, making much faster setup speeds and job changes possible. Furthermore, flexo presses offer long life expectancies and excellent returns on investment, provided they're properly maintained. These advantages of flexo printing cannot be overstated!

AUXILIARY DEVICES FOR FLEXO PRINTING PLATE MAKING

Flexo printing plate-making involves several steps. UV curing units and drying ovens cure and dry the plates, while flexo plate makers create them from scratch.

Flexo printing plates must be constructed from a material that can withstand the extreme temperatures and pressures encountered during printing. Rubber is the most common choice, but other materials like photopolymers or metals may also be utilized.

Once a desired material is selected, it must be cut to the precise size and shape. This is where auxiliary devices come into play; Flexo-plate-making machines can cut material to the precise dimensions as well as engrave any desired images or designs into the surface of the plate.

Once a flexo plate is made, it must be cured to make it harder and less susceptible to wear and tear. UV curing units expose plates to intense ultraviolet light, which hardens the material.

Drying ovens may also be used to cure flexo plates; however, this takes longer than UV curing units.Once the flexo plate is made and dried, it's ready to be used in the printing process.Making a flexo printing plate involves light-sensitive polymer, digital plate making, and molding.

HOW TO MAKE FLEXO PRINTING PLATES?

Nowadays, there are three ways to create a flexo plate.

In the first method, a film negative is placed over a light-sensitive polymer plate and exposed to UV lamp. As it passes through, the polymer hardens, leaving behind what looks like chewed gum on the plate. After washing out with water or solvent in a tank, any unexposed polymers are washed away using recycled water without adding detergent.

The second method uses CTP plate-making machine to etch the pattern directly from computer onto the plate.

The molding procedure is the third method of plate making. Aluminum plates can be obtained from the negatives after exposure to the acid bath.With this relief metal plate, you can make glass, or plastic molds in the first step.

When selecting a printing machine, the type of ink it can use is essential. Some flexography printing machines can only apply to water-based inks, while you can use both but others can use UV curable and water-based inks

No matter the method, mounting is critical for producing quality prints in the register. Precision mounting flexo plates on tape with laser pointers on an automatic mounting machine ensures consistent accuracy when printing plates onto print sleeves or carrier sheets for corrugated operations.

Mounting plates needs accurate positioning and a strong bond with a particular mounting tape.

Register marks such as crosses or microdots can be used, but they should be chosen carefully to guarantee the accurate superimposition of each color's image.

WHAT SHOULD CONSIDER WHEN SELETING A FLEXO PRINTING MACHINE ?

When selecting a flexo printing machine, several important factors must be considered. Most importantly, its printing speed. Depending on your application, you may require something capable of printing at rates up to 10,000 sheets per hour; however, slower speeds may suffice if only doing smaller jobs.

When selecting a printing machine, size and accuracy should be taken into account. For labels or other narrow materials like posters or banners, high accuracy is necessary to ensure the printed images appear sharp and clean. On the other hand, when producing wider materials like posters or banners, size may be more crucial than accuracy.For other flexo printing machines.Knowing what kind of inks will be most frequently utilized allows you to narrow down your selections of machines accordingly. Meanwhile, the quality of machine parts is a key factor too, it can ensure you run the machine continuously without any problems, and it can give the machine a long-service life.

Finally, after-sales service from your machine supplier should also be considered. Once you've invested in a flexo printing machine, training on its proper use and any potential issues with it is beneficial if someone can offer quick and helpful customer support.

CONCLUSION

Flexo printing is an innovative technology that offers businesses numerous advantages when searching for fast and cost-effective printing solutions. Due to its ability to print consistently high-quality images on various substrates without needing special coatings, fast production speeds, versatility, and low unit cost, it has become an ideal choice for industries such as packaging, textiles, and label printing. Flexo printing cylinders enable continuous patterns,enabling printers to complete complex designs within one print run. With its long history of innovation and adaptation to changing market demands, flexo printing has proven itself an efficient and dependable printing solution for businesses striving to stay competitive.

Flexo printing is more cost effective and speedy than other methods, making it ideal for highvolume jobs. Furthermore, this process uses less ink and produces less waste, making the process greener as plates can be reused multiple times. Flexo-printing has several environmental benefits as well.

Flexo printing is worth considering when looking for an economical yet high-quality printing solution. Due to its many advantages, this printing method has grown in popularity over the past few years and looks set to keep rising in the years ahead.

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