Common Challenges in Coding and Marking on Extrusions (and How to Overcome Them)

In industries like cable manufacturing, tubing, and pipe production, coding and marking on extrusions isn’t just about putting ink on plastic - it’s about ensuring compliance, traceability, and customer trust. Every mark matters, whether it’s a voltage rating on a cable, a batch code on a medical tube, or a pressure class on a pipe.

But extrusion environments are some of the toughest places to achieve high-quality, consistent codes. Surfaces are curved, lines run fast, and conditions are often hot, dusty, and unforgiving. In this article, we’ll explore the most common challenges manufacturers face with coding and marking on extrusions - and how to overcome them. Along the way, we’ll also look at technologies, best practices, and future trends that can help you get the most out of your marking systems.

Why Coding and Marking on Extrusions Matters

Before diving into the challenges, it’s worth asking: why put so much focus on coding in the first place?

Regulatory Compliance – Industries such as construction and electrical cabling are heavily regulated. Standards often require clear, permanent identification for safety and legal reasons

Traceability – Batch numbers and date codes help manufacturers track products through the supply chain, vital for quality assurance and recalls

Customer Confidence – A crisp, legible mark signals professionalism and reliability. Smudged or missing codes can damage a brand’s reputation

Branding Opportunities – Beyond compliance, coding allows manufacturers to add logos, product IDs, or even QR codes that connect customers to digital information

With so much at stake, poor or inconsistent printing can lead to costly waste, rework, and compliance risks.

1. Printing on a Moving Substrate

Extrusion lines rarely stop. With substrates constantly moving at high speeds, printers must keep up while maintaining clarity. If print isn’t synchronised with line speed, you’ll see stretched characters or blurred marks.

How to overcome it:

• Use printers with real-time line speed compensation
• Ensure encoder feedback is correctly installed and calibrated
• Position the printhead consistently relative to the extrusion

2. Printing on Curved or Uneven Surfaces

Unlike flat packaging, extrusions such as cables and tubes are round or irregular. This curvature can distort text or barcodes if not handled correctly.

How to overcome it:

• Choose non-contact technologies like Continuous Inkjet (CIJ) or laser that adapt well to curved surfaces
• Optimise the nozzle-to-surface distance to balance legibility and durability
• For very small diameters, consider printing simple, high-contrast codes instead of complex logos or data

3. Ink Adhesion and Durability

Materials like PVC, PE, and nylon can be challenging for ink to adhere to - especially if the surface is still warm from extrusion or coated with lubricants.

How to overcome it:

• Select inks formulated for plastics, such as pigmented or solvent-based inks
• Where adhesion is a recurring issue, consider surface treatments like corona or plasma
• Test inks for chemical resistance and abrasion durability to ensure codes survive handling, storage, and installation

4. Environmental Conditions on the Line

Extrusion lines are rarely clean environments. Heat, dust, and moisture can affect both the print quality and the printer’s reliability.

How to overcome it:

• Invest in printers with robust enclosures (IP-rated if necessary)
• Keep inks in a stable environment with controlled temperature and humidity
• Regularly clean nozzles, filters, and air systems to prevent clogging

5. Balancing Speed with Quality

Manufacturers often push for higher throughput, but faster line speeds can reduce print resolution and legibility.

How to overcome it:

• Match printer specifications with your maximum line speed
• Optimise font size and layout for clarity at speed
• Where needed, upgrade to high-performance printheads designed for high-speed applications.

Choosing the Right Printing Technology

Different extrusion applications benefit from different coding technologies:

Continuous Inkjet (CIJ): Ideal for high-speed, curved surfaces. Flexible but requires consumables

Laser Marking: Permanent, consumable-free, and precise — great for pipes and cables, but requires material compatibility and dust extraction

Thermal Transfer Overprinting (TTO): Best for flat extrusions like profiles or films. Produces sharp, durable prints but less suitable for curved surfaces

Selecting the right technology upfront is crucial for long-term reliability.

Ink and Material Considerations

Inks are not one-size-fits-all. Key factors to consider include:

Colour Contrast: White or yellow inks for dark extrusions, black for light-coloured substrates

Curing Speed: Fast-drying inks for high-speed lines prevent smudging

Environmental Resistance: UV-stable inks for outdoor products, chemical-resistant inks for automotive or medical use

Matching ink chemistry to extrusion material can make the difference between a mark that lasts and one that fades within weeks.

Real-World Use Cases

Cables: Voltage ratings, batch codes, CE or UL compliance marks

Pipes and Tubes: Diameter, pressure rating, manufacturing standard

Automotive Hoses: Part numbers, safety markings, colour-coded identification

Each sector has unique requirements, but all share the need for clarity, durability, and compliance.

Quality Control and Verification

A code is only useful if it’s readable. Increasingly, manufacturers are turning to inline vision systems that automatically verify print quality and reject defective products. Integration with MES or ERP systems allows for complete traceability, linking every extrusion to its production data.

Maintenance and Line Integration

Unplanned downtime is a manufacturer’s worst enemy. To keep coding systems running smoothly:

• Perform regular preventative maintenance (clean nozzles, replace filters)
• Position printheads for easy access during spool or reel changes
• Train operators to recognise early warning signs of misalignment or clogging

A well-integrated printer should fit seamlessly into the extrusion line, not slow it down.

Future Trends in Coding and Marking on Extrusions

The landscape is evolving quickly:

2D Codes (QR, Data Matrix): Offering greater data density and traceability

Eco-Friendly Solutions: Water-based inks and lasers reducing solvent use

Industry 4.0: Printers connected to smart factory networks for real-time monitoring, predictive maintenance, and data-driven optimisation

Forward-looking manufacturers are already adopting these technologies to gain a competitive edge.

Best Practices Checklist

To wrap things up, here’s a quick checklist for improving coding and marking on extrusions:

1. Choose the right printer technology for your substrate and speed
2. Test ink compatibility with your extrusion material
3. Maintain consistent printhead alignment and distance
4. Monitor line speed and synchronize printer settings
5. Implement vision systems for automatic quality control
6. Schedule regular maintenance to avoid downtime

Summary

Coding and marking on extrusions is one of the most demanding applications in industrial printing - but it’s also one of the most critical. By understanding the challenges and adopting the right solutions, manufacturers can achieve consistent, durable, and compliant markings that protect their brand and streamline production.

Whether you’re printing tiny batch codes on fibre optic cables or large compliance marks on PVC pipes, the right combination of technology, ink, and process control will ensure your extrusions are clearly identified - every time.

Contact us today to find out more and to discuss your requirements.