How to Choose Flexo Machines for Flexible Packaging Lines

Selecting the Right Flexo Press: Key Considerations for Packaging Printers

Choosing a flexo printing machine for a flexible packaging line is a strategic decision that affects print quality, operational efficiency, sustainability and return on investment. This guide explains the technical, commercial and operational factors to evaluate — from press architecture and ink systems to automation, service and total cost of ownership — so you can specify or buy a flexo printing machine that meets your current needs and scales with your business.

1. Understand Your Production Requirements: print volume, substrates and markets (flexo printing machine)

Before evaluating models, document these essentials:

• Annual and peak throughput (m²/month or million linear meters)
• Primary substrates: PE/PP/PA/PE-coated films, BOPP, PET, laminates, paper, corrugated board
• Required print quality: basic solid colors, high-resolution graphics (FM/AM screening), or photorealistic reproduction
• Typical repeat lengths and web width
• Customer expectations: food-grade inks, low-migration requirements, conformity with regional regulations

These parameters determine press class (narrow/web vs wide-web, central impression CI vs inline), number of color stations, and need for specialized drying or solvent recovery systems.

2. Press Architecture and Print Technology (flexo printer vs digital hybrid)

Common flexo architectures for flexible packaging:

• Central impression (CI) flexo — best for high registration accuracy and high-volume runs; ideal for multi-color flexible packaging where consistent registration is critical.
• Inline/stacked flexo — modular and cost-effective; easier to maintain but may need advanced registration systems for tight tolerances.
• Hybrid presses — combine flexo with digital or gravure units for short runs and variable data; good for diversified portfolios.

Choose CI when repeat lengths are long and registration demands are high. Choose inline or hybrid when flexibility and investment cost control are priorities.

3. Print Quality Factors: anilox, plate, impression and drying systems

Key determinants of print quality:

• Anilox roll: cell volume (BCM/cm²) and cell geometry control ink laydown and consistency. For fine halftone, use higher line screens and appropriate BCM.
• Plate technology: modern photopolymer plates with accurate imaging give better consistency than older rubber plates. Plate mounting systems and automation reduce repeat setup errors.
• Impression system: CI presses provide uniform impression, critical for high-quality solids and fine details.
• Drying/curing: IR/UV/Hot air systems must match ink type (water-based, solvent-based, UV, EB). Proper drying avoids set-off and enhances registration stability.

4. Production Speed, Throughput and Job Changeover (buy flexo printing machine)

Match press speed to line throughput. Typical ranges:

• Narrow-web flexo for labels/packaging: 100–400 m/min
• Wide-web flexo for flexible packaging: 200–600 m/min depending on drying capability and substrate

Also prioritize automation that reduces makeready time: automatic plate mounting, register presetting, motorized anilox adjustments and job recipe recall. Reduced makeready drives up effective throughput and lowers per-job costs.

5. Color Capability and Ink Systems (flexo printing press)

Decide the number of color stations you need — 1–10+ color units are available. Consider these options:

• Standard CMYK + spot colors for brand matches
• Extended gamut (6-7 color) units for broader color range and fewer spot inks
• Dedicated white or metallic stations for specialty effects

Ink type choices (water-based, solvent, UV/EB, low-migration for food) affect press configuration and workplace controls. Choose a press with compatible ink pumps, recirculation and solvent recovery if needed.

6. Web Handling, Tension Control and Registration

Good web handling prevents wrinkles, telescoping and registration drift. Features to look for:

• Closed-loop tension control with dancer rolls and load cells
• Automatic web guiding systems and edge sensors
• Servo-driven shafts and register control systems (camera/encoder-based)

These features matter more as press width and line speed increase.

7. Automation, Industry 4.0 and Remote Diagnostics (flexo printing machine for flexible packaging)

Invest in automation for consistent quality and lower labor dependence. Useful capabilities:

• Recipe management (press settings recalled per job)
• Automatic plate mounting and tension presets
• Inline inspection and color control (spectrophotometers, closed-loop color correction)
• Remote diagnostics and predictive maintenance to minimize downtime

8. Total Cost of Ownership (TCO): capital cost, consumables and uptime

Consider:

• Capital cost vs projected throughput and contribution margin
• Consumables: plates, anilox refurbishing, inks, films and cylinders
• Energy consumption (drying systems can be energy-intensive)
• Spare parts availability and service agreements

Calculate payback by modeling typical jobs, makeready reductions and scrap reductions the new machine can deliver.

9. Environmental, Health & Safety and Regulatory Requirements

For food packaging, confirm compatibility with low-migration inks and compliance with local regulations (e.g., EU Regulation (EU) No 10/2011, FDA guidance). Also evaluate solvent recovery and VOC controls if using solvent-based inks.

10. Installation, Training and After-Sales Service

Service and training often determine long-term success more than the machine’s base feature set. Check:

• Local service network and spare parts inventory
• Commissioning and operator training packages
• Availability of retrofit or upgrade paths (automation, additional stations)

Comparison Table: Typical Flexo Machine Classes and Use Cases

Note: CapEx ranges are indicative and vary by OEM, optional modules and regional installation costs.

Keshenglong & Shinko: Manufacturer Profile and Product Fit (corrugated carton flexo printing machine, flexo printing slotting die-cutting machine)

Keshenglong, founded in 1995, specializes in corrugated carton printing and packaging machinery and is a notable supplier for integrated packaging solutions. After merging with Japan Shinko in 2017, Keshenglong retained Shinko as the R&D center and production base, while adding a Guangzhou production facility. Key selling points:

• Product range: flexo printers, computerized high-speed flexo slotting die-cutting machines (1–6 color), flexo case makers, 6+1 high-precision precision printing slotting die-cutting machines, top & bottom printing slotting die-cutting machines, jumbo-size flexo printing slotting die-cutting machines.
• Technical strength: main components imported from Japan, assembly and calibration under experienced Japanese technicians, aiming to deliver Japanese-quality standards.
• Market reach: exported to more than 70 countries, positioned as a supplier of intelligent, integrated packaging solutions.

Why consider Keshenglong/Shinko for corrugated carton and flexo slotting die-cutting applications:

• Specialization in corrugated carton printing — combining flexo printing with inline slotting & die-cutting improves efficiency for box makers.
• High-speed computerized systems reduce makeready and improve alignment between print and conversion steps.
• Imported components and Japanese-led R&D provide a competitive edge in precision and durability.

Recommended models for converters who need integrated printing and converting on corrugated boards and large cartons include flexo printing slotting die-cutting and stacker machines that combine quality print with accurate die-cutting and efficient stacking — reducing floor space and manual handling.

Checklist: Questions to Ask OEMs and Suppliers (flexo printing machine)

1. Can you provide references with similar applications and throughput targets?
2. What is the expected makeready time for a standard job and what automation reduces it?
3. Which parts are imported vs local, and what are lead times for spares?
4. What training and commissioning packages are included?
5. Do you provide on-site startup support and performance guarantees?

Practical Buying Tips and Negotiation Points

Negotiate a package that includes:

• Service-level agreement (SLA) with guaranteed response times
• Consumables starter pack and recommended maintenance schedule
• Optional upgrades at a locked-in price
• Performance acceptance tests at installation

Also request a trial run or on-site demo with your substrates and typical artwork to validate color and registration performance before purchase commitment.

FAQs — Frequently Asked Questions

1. What is the difference between CI flexo and inline flexo?

CI (central impression) uses a single impression cylinder to support the substrate while multiple plate cylinders press against it, offering superior registration and consistent impression across colors. Inline presses have individual impression systems for each station and are often more modular and cost-effective for certain applications.

2. How many colors do I need on a flexible packaging flexo press?

It depends on product complexity. Many brands use CMYK + white + varnish; extended gamut (6–7 colors) can reduce spot inks. For metallics or special effects, dedicated white or metallic stations are required.

3. What is a reasonable ROI timeframe for a flexo printing machine?

ROI varies widely by utilization, labor savings, quality improvements and scrap reduction. Typical target payback for mid- to high-end machines ranges from 2–5 years when fully utilized and with optimized workflows.

4. Are flexo presses suitable for food packaging?

Yes, when configured with low-migration inks and appropriate barrier films. Ensure the press supplier can validate compliance with regional food-contact regulations and recommend suitable inks and lamination processes.

5. How important is automation in modern flexo presses?

Highly important. Automation reduces makeready time, improves repeatability, lowers waste and enables predictable throughput. Features like automated plate mounting, register preset, and remote diagnostics yield measurable productivity gains.

6. Can a flexo press be upgraded later?

Many OEMs offer modular upgrade paths (additional color stations, automation kits, inspection systems). Confirm upgradeability with the OEM to protect future investments.

Contact & Next Steps

If you want help specifying the right flexo printing machine for your flexible packaging line or to explore integrated corrugated solutions, contact our sales and technical team. View product options and request a demo or site survey to validate fit-for-purpose performance.

Contact Keshenglong for product catalogs, technical consultations, and quotations for corrugated carton flexo printing machines and flexo printing slotting die-cutting solutions.

References & Further Reading

• Smithers, The Future of Global Flexible Packaging to 2028 — market trends and forecasts. https://www.smithers.com (accessed 2024-08-12)
• Grand View Research, Flexible Packaging Market Size, Share & Trends (2023). https://www.grandviewresearch.com (accessed 2024-07-05)
• Flexible Packaging Association — industry resources and best practices. https://flexpack.org (accessed 2024-06-20)
• Wikipedia, Flexography — overview of flexo technology. https://en.wikipedia.org/wiki/Flexography (accessed 2024-05-10)
• European Commission, Regulation (EU) No 10/2011 on plastic materials and articles intended to come into contact with food. https://ec.europa.eu (accessed 2024-03-15)

For machine demos, detailed specifications, spare parts availability and region-specific compliance guidance, please reach out to Keshenglong's sales engineers.