This article is part of the FLEXO FLAW FIXING series

In the world of flexo printing, irregular specks can often be the bane of printers, resulting in unwanted spots, lines and other minor defects in flexo printing that compromise print quality. However, understanding the causes of these imperfections and implementing timely remedial action is critical to maintaining the integrity of printed materials.

Common Causes and Corresponding Remedies

Here we look at some common causes of these annoying problems and offer practical solutions to keep your prints pristine.

Insufficient Ink Levels
  • Cause: An often overlooked culprit behind inconsistent prints is low ink levels. When a printer runs out of ink, it can cause prints to be marred by speckles and stains.
  • Remedy: Regular monitoring and replenishing of ink can prevent this. The introduction of an automatic ink level monitoring system could act as a failsafe, ensuring that your press never runs dry.
Unlevelled Printing Units
  • Cause: Moving on, an unlevelled press can spell disaster, leading to skewed and blurred results.
  • Remedy: Accurate setup and regular calibration of press equipment is essential. The use of spirit levels and a regular check and balance routine can prevent such problems before they affect print runs.
Undue Environmental Exposure
  • Cause: Colours can fade or smear due to exposure to light or humidity, so environmental factors can also play an unpleasant role.
  • Remedy: Protecting the printing environment from these elements is essential. Store paper in a controlled climate and ensure that files are handled in a way that prevents excessive exposure.
Dust Particles on Substrate
  • Cause: Dust particles are often the main culprit when it comes to unexpected stains on your substrate.
  • Remedy: A clean and dust-free working environment, combined with careful substrate preparation, can help to avoid these problems. Incorporating air filters or special cleaning equipment for the print area could be a worthwhile investment.
Static in Substrate
  • Cause: Static electricity can also attract dust and cause it to stick to the substrate.
  • Remedy: Incorporating anti-static measures such as anti-static bars or rollers can help. For persistent static problems, consider investing in equipment that neutralises the charge before printing.
Dirty Feeders or Rollers
  • Cause: Do not overlook the condition of feeders, rollers and the rest of the press.
  • Remedy: Even the smallest residue left behind can lead to stains and imperfections. A programme of routine cleaning and maintenance checks should be established to prevent such defects.

Conclusion

Flexo printing, while efficient, requires attention to detail and proactive maintenance to prevent minor defects from escalating into costly problems. From regular machine maintenance to strict environmental controls, every step taken to mitigate these issues contributes to a cleaner, sharper final product.

While the cost of preventing stains and imperfections may seem inconvenient, it is a small price to pay for consistent excellence compared to the potential loss of quality, customer satisfaction and, ultimately, profit.

The quest for perfection in print is a meticulous one, but it is not unattainable. With the right knowledge and practices in place, your flexo printing operation can be free of irregular spots, ensuring that every roll that comes off the press is as flawless as the last.