What Is a Flexo Printing Machine?

A flexo printing machine is a high-efficiency printing system that uses flexible relief plates to transfer ink onto a wide range of packaging and labeling materials. Known for its speed, versatility, and ability to run long production jobs with consistent quality, flexographic printing is widely used in food packaging, labels, flexible films, corrugated boxes, and industrial materials. Its adaptability to various substrates and inline finishing processes makes it one of the most important technologies in modern packaging production.

How Flexo Printing Machine Works

Flexographic printing uses a series of rotating cylinders to transfer ink from an anilox roller to a flexible photopolymer plate, which then prints the image onto the substrate. The workflow generally includes:

1. Ink Metering – Ink from the ink pan is metered evenly onto the anilox roller.

2. Ink Transfer – The anilox roller transfers the controlled ink layer to the relief plate.

3. Image Printing – The plate cylinder prints the image onto the moving substrate.

4. Drying/Curing – Between colors, hot air or UV curing systems dry the ink to prepare for the next layer.

5. Rewinding or Inline Conversion – The material is rewound or sent to post-press functions.

This continuous process allows flexo machines to reach high speeds (often 100–200 m/min or more) with stable color accuracy and repeatability.

Inks Used in Flexographic Printing

Flexo printing supports several ink types, each suited to specific materials and applications:

1. Water-Based Inks

Common in paper packaging and labels; eco-friendly with strong adhesion.

2. Solvent-Based Inks

Ideal for films like PET, BOPP, or PVC; fast-drying and durable.

3. UV-Curable Inks

Cured with ultraviolet light; offer high gloss, sharp detail, and excellent chemical resistance.

4. LED-UV Inks

Energy-efficient curing, low heat emission, suitable for heat-sensitive substrates.

Different ink systems allow flexo presses to handle packaging for food, cosmetics, pharmaceuticals, and industrial uses.

Substrates Compatible with Flexo Printing

Flexo printing machines are highly versatile and can print on:

• Paper & cardboard – labels, cartons, corrugated packaging

• Flexible films – BOPP, PET, PE, PVC, and laminated films

• Foils and metallic films

• Adhesive label stock

• Nonwoven materials – tissues, hygiene products

• Specialty substrates – shrink sleeves, tags, tickets

This wide substrate compatibility is one of the strongest advantages of flexographic technology.

Prepress, Platemaking, and Press Setup

Flexo printing depends heavily on precise prepress and plate preparation:

1. Prepress

Digital files are processed for trapping, color separation, distortion compensation, and screening.

2. Platemaking

Photopolymer plates are produced using digital laser imaging (CTP) and UV exposure. Plate quality directly impacts print sharpness and consistency.

3. Press Setup

Key setup elements include:

• Installing plates on plate cylinders

• Mounting anilox rollers with the correct line count and volume

• Adjusting ink viscosity

• Setting impression and register

• Testing drying performance

A correct setup ensures minimal waste, stable colors, and smooth operation at high speeds.

Post-Press Processing

Flexo Printing Machine often integrate inline finishing processes to complete the product without additional machinery. Typical post-press functions include:

• Die-cutting – for labels, stickers, and packaging shapes

• Laminating – for added strength, barrier protection, or gloss

• Cold or hot foiling – for premium packaging

• Slitting and rewinding – converting printed rolls into final usable widths

• Varnishing or coating – matte, gloss, spot UV, or protective layers

Inline post-press operations improve efficiency, reduce handling, and ensure consistent quality.

Conclusion

A flexo printing machine is a versatile, fast, and widely used printing technology that supports many inks, substrates, and inline finishing techniques. With precise prepress workflows, advanced plate technology, and efficient post-press options, flexographic printing remains a top choice for high-quality packaging, labels, and industrial printing applications.