Converting is a complex industrial process that transforms raw materials, such as rolls of paper, paperboard, or plastic films, into finished products ready for use. In this context, flexography stands out as the leading printing technology thanks to its ability to integrate seamlessly into production lines, which combine sequential operations such as printing, laminating, coating, die-cutting, folding, and gluing. Printing is just one stage of this workflow, yet it remains a crucial step for ensuring the quality and functionality of the final product.
1. High substrate versatility (“Print on any material”)
Flexography is the only conventional printing process capable of effectively printing on a wide range of substrates, making it strategically valuable for converting companies aiming to diversify production:
Paper and paperboard:
- Corrugated board (Die‑Cut): The flexible photopolymer plate can gently “kiss” the irregular corrugated surface without compromising its structure, making flexography ideal for high‑graphic shipping boxes and display packaging.
- Paper bags and sacks: Excellent performance on both porous and smooth surfaces.
- Folding cartons: Delivers high graphic quality on coated board.
- Tissue and Hygienic products: The gentle impression of flexographic printing is essential to avoid damaging extremely thin and absorbent materials.
Plastics and films:
- Flexible packaging: Outstanding results on extensible films (PE, PP).
- Pressure‑sensitive labels: The dominant technology for labels on paper and plastic substrates, including transparent ones.
- Shrink sleeves: Capable of printing on heat‑sensitive materials designed to conform to container shapes.
- Laminates and foils: Easily handles complex multilayer structures and metallized substrates.
This versatility enables converting companies to serve a broad range of sectors (food, pharmaceutical, industrial, and consumer goods) maximizing equipment utilization and productivity.
2. Seamless Inline Process Integration
Modern converting follows an integration‑driven approach to boost efficiency, reduce costs, and enhance operational responsiveness. Flexography, with its mechanical simplicity, modularity, and reliability, represents the ideal printing module for incorporation into complex, automated production lines.
Intrinsic Modularity: Flexographic printing units are compact and easily integrated with other converting modules.
Application examples:
- Corrugated box plant: A single line can include a feeder → flexographic printing unit → slotter/scorer → die‑cutter → folder/gluer → stacker, delivering a finished product in a continuous flow.
- Label press: Narrow‑web presses function as fully integrated converting lines: unwinders → printing units → UV curing → foil application → lamination → die‑cutting → slitting → rewinding.
- Rapid Drying / Curing: Water‑based, solvent‑based, or UV/EB inks enable instant drying, dramatically reducing process stage times and minimizing defects such as smearing or scuffing.
3. “Perfect balance” between cost‑effectiveness and quality
Flexography offers an optimal balance between graphic quality and cost control, making it the most advantageous technology for the majority of packaging applications.
- Plate cost and lead time: Photopolymer plates are cost‑effective and fast to produce, with significantly shorter setup times compared to gravure cylinders.
- Run‑length flexibility: Competitive for medium/long runs (versus digital) and also for short/medium runs (versus gravure), where flexography is the preferred choice for dynamic and variable volumes.
- Quality advancements (HD Flexo): Innovations such as flat‑top dots, advanced screening, and high‑definition imaging now enable print quality comparable to offset and gravure, while retaining the economic and productivity advantages of flexography.
Competing printing technologies: less suited for industrial converting
While alternative technologies have specific merits, they are less suited to the combination of flexibility, in‑line integration, and cost efficiency demanded by modern packaging converting operations.
1. Gravure (Rotogravure)
An ultra‑high‑definition process suitable only for industrial contexts with extremely high volumes and highly stable graphic layouts.
Weak points:
- High cylinder cost: Prohibitively expensive with turnaround times unsuited to dynamic markets.
- Limited substrate versatility: Requires smooth surfaces; unsuitable for rough materials like corrugated board.
- Production rigidity: Poorly suited to short runs or frequent design changes.
Gravure retains a niche in ultra‑specialized, high‑volume segments such as tobacco packaging, lottery tickets, and premium confectionery but is steadily declining in favor of HD flexography.
2. Offset
The reference technology for commercial printing (magazines, brochures, books), but inadequate for the specific requirements of packaging converting.
Weak points:
- Water/Ink balance: The chemical principle of water‑ink repulsion is sensitive and unsuitable for high‑speed, robust processes.
- Limited substrate versatility: Optimized for smooth paper; inefficient on plastics, laminates, foils, or corrugated board, even in UV or sheet‑fed offset variants.
- Poor inline integration: Machine footprint and complexity hinder integration with other modules. Additionally, ink drying times are incompatible with fast production flows.
Offset is mainly used for high‑quality folding cartons (via sheet‑fed offset) and certain label applications.
3. Digital printing (Inkjet & Toner)
Digital printing is the most advanced competing technology but plays a complementary role in industrial converting. It excels in specific niches but cannot replace flexography at scale.
Weak points (for large‑scale converting):
- Speed and throughput: Industrial digital presses cannot match the performance of flexographic lines (300–600 m/min), causing bottlenecks.
- Cost at scale: High ink or toner costs make digital printing economically unviable for medium to long runs.
- Inefficient integration: Digital printheads can be integrated but impose trade‑offs on speed and operational flexibility.
Digital printing is gaining ground in niches such as prototyping, ultra‑short runs, personalization, and variable‑data printing. However, these applications represent only a minor share of the total market, where flexography remains the dominant technology due to its superior balance of speed, cost, and versatility.
Written by Lorenzo A. | Team Giugni®
