How to achieve high-quality flexographic printing on aluminum foil bags?

Time:

2020-12-21

Source:

Flexographic Printing Method for Aluminum Foil Bags, Part 1: Effectively Selecting the Screen Line Count

The effective selection of screen ruling depends crucially on the fidelity of the proof copy. In addition, factors such as printing plate-making equipment, printing machinery, and printing materials must also be taken into account. Under identical conditions, the screen ruling used in flexographic printing is generally lower than that used in offset and gravure printing.

Flexographic Printing Method for Aluminum Foil Bags, Part 2: Appropriately Selecting the Outlet Design

Under normal circumstances, with the network line density and the percentage of service outlets held constant, square-shaped service outlets exhibit more pronounced expansion when the proportion of such outlets reaches approximately 50%, at which point the diameter of the square outlets is larger; by contrast, circular-shaped service outlets show more significant expansion when this proportion is around 70%, at which point the diameter of the circular outlets is greater. Furthermore, in the ranges of 10%–50% and 80%–90%, the level of outlet expansion for square-shaped outlets exceeds that for circular-shaped outlets; whereas in the range of 60%–70%, the opposite holds true, with circular-shaped outlets exhibiting greater expansion than square-shaped ones.

Flexographic Printing Method No. 3 for Aluminum Foil Bags: Application of Hybrid Screening Technology

The performance of hybrid screening technology enables seamless transitions between arbitrary halftone screens and traditional halftone screens, with 5%–10% and 90%–95% tonal ranges being handled through intelligent, fully automated processing rather than simple, density-based interpolation. Compared with conventional screening techniques, this approach results in more uniform and predictable expansion of highlight and shadow areas, allowing for effective reduction during prepress preparation.

Another advantage of employing hybrid screening is that it broadens the range of halftone reproduction in aluminum foil bag printing, enabling tone reproduction from 0% to 99.9% in most cases. For flexographic printing, since halftones in shadow areas are often difficult to reproduce, the use of hybrid screening provides an excellent solution to this challenge.

Flexographic Printing Method for Aluminum Foil Bags, Part 4: Adjusting the Halftone Compensation Curve

Typically, the hierarchical compensation curve is adjusted during process optimization to expand certain areas of the printing press while reducing others, thereby bringing the final aluminum foil bag printing gradation curve closer to the ideal gradation reproduction curve.

Although current advances in prepress technologies for electronic devices, laser image-output techniques, and optical-density measurement methods have provided several favorable approaches for managing the expansion of printing operations, the inherent diversity of printing technologies and the rapid evolution of printing processes continue to pose significant challenges for many aluminum‑foil bag printing companies seeking to expand their operations. Therefore, a thorough understanding of the factors driving operational expansion and the adoption of appropriate control strategies can help these companies produce high‑quality printed materials.

Previous item

Case Study: Decolorization Treatment of Wastewater from a Printed Carton Manufacturing Plant

None

Next item

National Service Hotline

021-64100077

Address: No. 3632, Zhaolou Road, Minhang District, Shanghai

Email: eternal@eternal.com.cn

We are here.