Inkjet Printing for Flexible Packaging Materials: Challenges and Solutions

Inkjet Printing for Flexible Packaging Materials: Challenges and Solutions

Inkjet printing technology has evolved tremendously in the last decade, and a range of industries is using it to print images on different substrates. The packaging industry is no exception and has adopted inkjet printing to print on various materials, including flexible packaging. Flexible packaging offers many benefits and is ideal for products that need high barrier protection and extended shelf life.

However, printing on flexible packaging is not a straightforward task. The materials used in flexible packaging are non-porous and have low surface energy, which makes adhesion of the inks difficult. Moreover, flexible packaging materials are often thin, and the inks should not distort or smudge the surface. This article discusses the challenges faced by inkjet printing on flexible packaging materials and the solutions to overcome them.

Challenges of Inkjet Printing on Flexible Packaging Materials

1. Image Quality -

Flexible packaging materials have a porous surface and low surface energy that make the ink spread and bleed. This can result in poor print quality, sharpness, and edge definition. Moreover, printing on thin materials can cause distortion or smudging, which further deteriorates the image quality.

2. Adhesion -

Inks used in inkjet printers may not adhere well to non-porous, low surface energy substrates like flexible packaging. Poor adhesion results in the ink peeling or flaking off, which reduces the image quality and overall aesthetics of the packaging.

3. Durability -

Flexible packaging materials are used to protect the products and maintain their freshness, durability, and shelf life. Therefore, the inks used in inkjet printers should be durable and resist fading, scratching, and environmental factors.

4. Color Consistency -

Flexible packaging materials come in different colors and textures. The inks used for printing should be consistent and match the color and texture of the substrate. Inconsistent color can result in a mismatched or unappealing print.

5. Ink Consumption -

Inkjet printing is an efficient method of printing as it prints only the required amount of ink. However, printing on flexible packaging requires more ink to achieve the desired optical density and image quality, resulting in increased ink consumption and cost.

Solutions to Inkjet Printing on Flexible Packaging Materials

1. Surface Preparation -

The inkjet printing on flexible packaging materials can be made possible by preparing the surface by plasma or flame treatment, corona treatment, and chemical modification. These methods increase the surface energy of the material to promote adhesion and prevent ink bleeding. This allows the ink to penetrate and bond to the surface of the packaging, resulting in sharper edges and images with better color accuracy.

2. Ink Selection -

Inks for flexible packaging should have a low viscosity, high adhesion, and fast drying properties. UV curable inks work best as they solidify instantly with UV radiation, reducing the risk of ink smudging and distortion. Solvent-based inks also work well as they can penetrate non-porous surfaces and dry quickly, resulting in consistent and durable images.

3. Print Head Selection -

The print head selection is crucial for printing on flexible packaging materials. Piezoelectric inkjet print heads are preferable as they produce good quality prints, have high accuracy, and can handle a wide range of inks. Moreover, the print heads should be able to print at high speeds to increase the productivity and throughput of the printing process.

4. Ink Volume -

Optimizing the ink volume is essential for achieving consistent and vibrant colors without wasting ink. The ink volume can be adjusted according to the substrate and the printing process. Inkjet printers can use nozzle check systems to ensure that ink is not wasted or over-applied during the printing process.

5. Quality Control -

A quality control system should be put in place to ensure the consistency and quality of the printed images. This system can include regular checks of the printing process, inspection of the printed material, and maintenance of the equipment. The quality control system can ensure that the printed packaging meets the required specifications, reducing the need for reprints and waste.

Conclusion

Printing on flexible packaging materials is a complex process that requires careful consideration of multiple factors. Inkjet printing technology offers a reliable solution for printing on flexible packaging, but it requires the right equipment, ink, and surface preparation. Addressing the challenges of inkjet printing on flexible packaging materials can ensure that the printed packaging meets the required specifications and maintains the integrity of the product inside.