Comparison of Gravure and Flexographic Printing in Food Packaging: Considerations for Eco-friendly Packaging

Gravure VS Flexo

Introduction

 

The printing methods for food packaging significantly impact the product's quality, brand image, and food safety. Gravure and flexographic (flexo) printing are the most common methods used in food packaging printing. However, considerations on the environmental impact and potential harm to humans from these printing methods have become increasingly important. Let's explore gravure and flexo printing.

 

Gravure printing

 

,known for its high-resolution and wide color range, is commonly used in food packaging printing. However, this method is designed for mass production, and the waste and chemical use during the printing process may negatively impact the environment. The inks used in gravure printing may contain harmful chemicals that could be a direct threat to food safety.

 

On the other hand, flexo printing is recognized as a more eco-friendly printing method. It uses less ink than gravure printing, minimizing chemical use and reducing waste generated during the printing process. However, flexo printing is not completely eco-friendly, and considerations like waste disposal and energy consumption during the printing process are required.

 

Food packaging printing is not just about beautifying the product; it's a complex issue that requires considerations on environmental and human health impacts. Raising awareness and understanding of this issue is a crucial responsibility of food packaging manufacturers. Gravure Printing Gravure, a French word meaning "intaglio printing," requires an intaglio plate for automatic and continuous processes, creating a cylindrical plate. The ink fills the engraved grooves on the cylindrical plate and is transferred to the film.

 

The process consists of the following steps:

 

1. Copper Plate Production: The design to be printed is created on a computer and engraved on a copper plate using lasers. The depth of the engraving depends on the intensity of the color to be printed.

2. Chrome Plating: Once the copper plate is produced, the surface undergoes a chrome plating process. This step creates tiny grooves on the surface of the plate, improving the print quality by better holding the ink.

3. Ink Application: Once the plate is ready, the ink of the color to be printed is poured into a tray. The plate is arranged so that one side touches the tray, and the other side touches the film. As the plate rotates, the ink fills the engraved parts of the plate.

4. Ink Scraping: The ink-coated plate is scraped using a tool called a Doctor Blade. This process removes the ink from the unengraved parts, leaving ink only in the engraved parts.

5. Printing: The ink-coated plate comes into rapid contact with the paper, transferring the print image. At this point, the plate applies high pressure to the paper.

6. Rewinding: Finally, the film passes through a dryer to ensure the ink is completely dry. The solvent evaporates, and the film is then rewound to produce the final print. Each step of gravure printing plays an important role in print quality.

 

Flexo Printing Flexo printing goes through a somewhat different process, mainly consisting of the following steps:

 

1. Plate Production: Flexo printing uses a flexible rubber or plastic printing plate. The design to be printed is engraved on this flexible plate.

2. Ink Application: Once the plate is ready, the ink of the color to be printed is applied to the plate. The ink sticks to the grooves of the Anilox roll and is then transferred to the raised resin plate where the design is.

3. Ink Scraping: Flexo printing's ink scraping process differs from that of gravure printing. The ink applied to the printing plate is removed using a roller instead of a scraper, leaving ink only in the engraved parts.

4. Printing: The ink-coated raised resin plate comes into contact with the film, transferring the print image. The printing plate applies pressure to the paper at this point.

5. Drying: Finally, the paper passes through a dryer to ensure the ink is completely dry.

 

The paper is then rewound to produce the final print. Compared to gravure printing, flexo printing shows differences in the materials of the printing plate and the method of ink scraping. These differences affect the characteristics and quality of the products each printing method produces.

 

Differences in Printing Techniques

 

Gravure and flexo printing each have their features. The key differences between them are:

 

1. Amount of Ink: Gravure printing applies a large amount of ink through deep engraving, offering higher color intensity and better image quality, but it may take longer to dry. Flexo printing applies ink on the surface, so it uses less ink. This allows for faster drying times, but the color intensity may not be as high as gravure printing.

2. Plate Production and Reusability: Gravure printing requires a new plate for each design, and since it uses copper plates, the cost is quite high. If the design changes, a new printing plate is needed. In contrast, flexo printing uses flexible rubber or plastic plates, which are relatively cheaper, and design changes are easier.

3. Printing Speed: Gravure printing offers high print quality but has a slower printing speed. This is because it applies a lot of ink, which requires more drying time. Flexo printing uses less ink, so it dries faster, allowing for faster printing speeds.

4. Environmental Suitability: Flexo printing can use water-based inks, making it more eco-friendly. In contrast, gravure printing often uses solvent-based inks, which can have a larger environmental impact.

 

Conclusion

 

We have explored the gravure and flexo printing methods used in food packaging. Flexo and gravure printing are two major printing technologies commonly used in graphic design and commercial printing. Flexo printing, a printing technique using flexible plates made of rubber or plastic, is mainly used for packaging, labels, shopping bags, etc. It has the advantages of fast printing speed, suitable for mass production, and can be used with various inks and materials. Gravure printing is a printing technique that directly engraves the image onto a metal plate and applies ink.

 

This technique provides high-resolution prints and is mainly used when clear images are needed, such as magazines, catalogs, packaging, etc. The biggest difference between these two printing techniques is the materials used for the plates and how ink is applied during the printing process.

 

Flexo printing uses flexible plates, and ink is applied to the plate's surface, while gravure printing uses engraved metal plates, and ink fills the engraved parts. However, an essential point here is the risks these printing techniques can expose consumers to when used in food packaging. Printing inks can directly or indirectly affect food, and chemicals in the ink can migrate to the food. This problem can be particularly severe in plastic packaging or labels.

 

Therefore, there is a growing need for eco-friendly printing techniques. Eco-friendly printing techniques focus on using materials that do not harm the environment, minimizing waste generated during the printing process, and improving energy efficiency. Additionally, the use of eco-friendly packaging and printing inks considering food safety is required.

 

In conclusion, while both flexo and gravure printing techniques have their advantages, considerations for consumer health and environmental protection are necessary for food packaging printing. The development and application of eco-friendly printing materials and techniques are essential, and this is a crucial part of indicating the future direction of the printing industry.