How Many Types of Flexo Printing Are There?

Flexographic printing (flexo) dominates modern packaging production. This versatile method prints on everything from potato chip bags to shipping boxes. But how many types of flexo printing exist? The industry recognizes three main press configurations: Central Impression (CI), inline, and stack. Each serves distinct purposes across global packaging supply chains. This popular method uses flexible plates to print on almost any material. CI presses offer precision for food wraps. Inline machines handle colorful labels. Stack systems print thick materials like boxes. Knowing these types helps choose the right solution.

Flexo printing brings your favorite packages to life. The right press saves time and money while creating better quality prints. Let’s explore how these three systems work and why flexo remains essential for modern packaging.

What Is Flexographic Printing?

The Basics of Flexo Printing

Flexographic printing (flexo) is a modern analog printing technology. It uses flexible photopolymer plates to transfer ink onto various materials. This method dominates packaging production worldwide.

How It Works

The process involves five key components:

1. Printing Plates

• Rubber or photopolymer material

• Raised image areas (0.02-0.25mm height)

• Can wrap around cylinder

1. Anilox Rollers

• Laser-engraved ceramic surface

• Controls ink volume (4-12 BCM/sq in)

1. Doctor blade removes excess ink

  3. Ink Systems

• Water-based (53% market share)

• Solvent-based (32%)

• UV-curable (15%)

  4. Substrates

• Handles materials from 10μm films to corrugated board

• No surface pretreatment required

  5. Drying Methods

• Hot air (most common)

• UV curing (instant drying)

• Infrared (energy efficient)

  
  

How Many Types of Flexo Printing Presses Exist?

Three primary types—Central Impression (CI), Inline, and Stack—each with unique configurations and uses.

1. Central Impression (CI) Flexo Presses

Central Impression (CI) flexographic presses feature a unique “planetary” design where all print stations surround a single large impression cylinder.

Key Characteristics:

• Single Impression Drum: Massive steel cylinder (typically 5-15ft diameter) serves as the foundation.

• Radial Station Arrangement: 6-10 color units positioned around the central drum.

• Web Path: Substrate wraps 270°-300° around the impression cylinder.

• Tension Control: Maintains 2-10 lbs/linear inch for delicate materials.

Technical Specifications:

| Parameter | Specification Range | Industry Standard |

|-----------------------|-----------------------------|------------------------|

| Web Width | 40"-100" (1-2.5m) | 65" |

| Maximum Speed | 1,000-2,000 fpm (300-600m/min)| 1,500 fpm |

| Register Accuracy | ±0.0005" (±12.7μm) | ±0.001" |

| Dryer Capacity | 50-100 kW per color | 75 kW|

| Ink Systems | Water/Solvent/UV/EB | Solvent-based|

| Typical Substrates | 12-500μm thickness | 25-100μm films|

Advantages:

1. Superior Registration

• Maintains ±0.001" tolerance even on stretchable films.

   2. Material Versatility

• Handles thin gauge films (as low as 12μm).

   3. Production Efficiency

• 30% faster than inline presses at comparable quality.

Limitations:

• Changeover Complexity: Requires 45-90 minutes for job transitions.

• High Capital Cost: $2M-$5M initial investment.

Primary Applications:

• Flexible food packaging (e.g., potato chip bags).

• Medical packaging (e.g., sterile wraps).

2. Inline Flexo Presses

Inline flexographic presses arrange print stations sequentially along a horizontal web path.

Key Characteristics:

• Linear Configuration: Independent print units in straight-line arrangement.

• Servo Technology: Modern versions use electronic shaftless drives.

Technical Specifications:

| Parameter | Specification Range | Industry Standard |

|-----------------------|-----------------------------|------------------------|

| Web Width | 13"-80" (330mm-2m) | 20"-40" (Mid-web) |

| Maximum Speed | 500-1,200 fpm (150-365m/min)| 800 fpm |

| Register Accuracy | ±0.001" (±25μm) | ±0.002" |

Advantages:

1. Production Flexibility

• Modular design allows adding foil stamping/die-cutting units.

    2. Economic Factors

• Lower investment ($500K-$2M) compared to CI presses.

Limitations:

• Web stretch affects multicolor alignment.

Primary Applications:

• Pressure-sensitive labels (e.g., beverage labels).

• Folding cartons (e.g., cereal boxes).

3. Stack Flexo Presses

Key Characteristics:

• Vertical Configuration: Print decks stacked 2-4 high.

• Space Efficiency: 40% smaller than equivalent CI press.

Technical Specifications:

| Parameter | Specification Range | Industry Standard |

|-----------------------|-----------------------------|------------------------|

| Web Width | 20"-60" (500mm-1.5m) | 40" |

| Maximum Speed | 400-800 fpm (120-240m/min) | 600 fpm |

Advantages:

• Cost Effective: 30-50% cheaper than CI presses.

• Durability: 20+ year lifespan with proper care.

Limitations:

• Unsuitable for <50μm films.

Primary Applications:

• Corrugated packaging (e.g., shipping boxes).

• Paperboard products (e.g., frozen food boxes).

  
  

How to Choose the Right Flexo Press

Key Considerations

1. Application: Match press type to substrate (e.g., CI for films).

2. Volume: CI for long runs; inline for shorter jobs.

3. Budget: Stack presses are affordable; CI offers ROI for high volume.

Industry-Specific Recommendations

| Industry | Recommended Press Type |

|---------------------|-----------------------------|

| Flexible Packaging | CI or Wide Web |

| Labels/Tags | Inline Narrow Web |

| Corrugated Boxes | Stack or Wide Web |

FAQs About Flexo Printing Types

1. Which flexo press is fastest?

A: CI presses, designed for high-speed production.

   2. Can flexo print on both sides of a substrate?

A: Yes! CI and stack presses offer double-sided printing.

   3. Is flexo printing expensive?

A: Costs vary—stack presses are budget-friendly; CI presses require higher investment but excel in volume.

   4. What’s the most common flexo press?

A: Inline, due to versatility and label market demand.

Conclusion

Flexographic printing offers three primary press configurations: Flexographic printing offers three primary press configurations - Central Impression (CI), inline, and stack - each designed for specific production requirements. CI presses excel in high-speed, precision printing of flexible packaging, while inline systems dominate label production with their modular flexibility. Stack presses remain relevant for corrugated and paperboard applications despite their declining market share. The choice between these systems depends on substrate type, print quality needs, production volume, and budget considerations. As the packaging industry evolves, flexo technology continues to adapt through hybrid digital solutions and automated controls, maintaining its position as the dominant printing method for 68% of global packaging production. Understanding these three fundamental press types enables manufacturers to optimize their operations for quality, efficiency, and cost-effectiveness.