Use The Correct Ink & Solvent To Prevent Rubbing off or Smudging Best Before Dates

Why Your Expiry Date is Fading: Common Causes and Fixes in Coding

In the fast-paced world of manufacturing and packaging, clear and legible expiry dates are non-negotiable. They ensure compliance, protect brand integrity, and—most importantly—safeguard consumers. So when those expiry dates begin to fade, it’s more than a minor hiccup—it’s a red flag.

If you’ve noticed inconsistent or fading codes on your products, here’s a breakdown of the most common causes, and more importantly, how to fix them.

1. Ink and Solvent Issues

Cause:
In Continuous Inkjet (CIJ) printers, using the wrong ink or running low on solvent can result in light or disappearing prints.

Fix:

• Ensure you’re using the correct ink formulation for your substrate.
• Regularly check ink and solvent levels.
• Monitor ink viscosity—CIJ printers rely on precise viscosity for consistent droplet formation.
• If you're coding onto dark or oily surfaces, consider switching to high-contrast or pigmented inks.

2. Poor Printhead Maintenance

Cause:
Dried ink, dust, or debris on the printhead can block nozzles and cause streaky or weak prints.

Fix:

• Follow a strict cleaning schedule using manufacturer-approved cleaning solutions.
• Use auto-flush features if available.
• Train operators on proper daily start-up and shutdown procedures.

3. Wrong Substrate or Surface Contamination

Cause:
Some materials, like glossy plastics or oily metals, resist ink adhesion. Dust, moisture, or oil on the surface can also repel ink.

Fix:

• Switch to an ink designed for that specific substrate.
• Add a pre-treatment step (like a wipe or air blast) to clean the surface before coding.
• Consider using laser coding or thermal transfer if the substrate is particularly difficult.

4. 4. Line Speed Mismatch

Cause:
If your printer can’t keep up with the speed of your production line, characters may appear incomplete or smudged.

Fix:

• Ensure the coder is rated for your production line speed.
• Use encoders to synchronize print speed with conveyor movement.
• Upgrade to a high-speed printer like the Linx 8940 Spectrum or Matthews VIAjet L-Series for speed-critical environments.

5. 5. Environmental Factors

Cause:
High humidity, temperature swings, or excessive dust can all affect print quality.

Fix:

• Install printers in controlled environments when possible.
• Use enclosures or filters to protect sensitive printheads.
• For dusty environments (like milling or food factories), integrate a fume or dust extraction system.

Fading expiry dates don’t just affect your packaging—they affect your reputation. Whether you're coding onto a carton, can, bottle, or bag, your message must be clear, legible, and lasting.

Every fading issue has a fix. From switching to high-contrast inks to re-calibrating your printer, small adjustments can restore crystal-clear coding and peace of mind.

And if you're still struggling with unclear dates, it may be time to consult an expert or upgrade to a more reliable system.