News

Q1: What should I do if "hairy edges" appear during flexographic printing?

A: Hairy edges refer to uneven printed text and image edges, appearing jagged or irregularly blurred. This is largely caused by ink issues, such as excessive ink viscosity or overly fast ink drying. Solutions include: controlling ink pH between 8.5–9.5 at 25°C room temperature; selecting anilox rollers with higher line counts or lower ink volume; using anti-static devices when necessary; and keeping the substrate surface clean.

Q2: Why do cut depths vary (some cuts deep, others shallow)?

A: This often occurs when the cutting strip (cushion) becomes uneven from prolonged use. Most digital die-cutters use a soft PVC or rubber cutting strip that develops grooves over time. Solutions: replace the cutting strip; as a temporary fix, slightly increase cutting pressure (by 200–300 units) to compensate; rotate the cutting strip regularly to extend its life.

Q3: What causes the "ghosting" phenomenon in flexographic printing?

A: Ghosting appears as faint repeated images in areas where they shouldn't appear, typically in large solid printing areas. The main cause is insufficient ink replenishment in anilox roller cells. Improvement measures include: switching to an anilox roller with the same ink volume but lower line count; slightly increasing ink viscosity; protecting the anilox roller from hot air drafts; and reducing doctor blade pressure.

Q4: How to eliminate printing streak marks?

A: The root cause of printing streaks is unstable printing pressure. Common causes and solutions: damaged transmission gears or roller cores—maintain gears properly; uneven printing content—change imposition methods or add balance bars; excessive concentricity deviation of rotating parts—choose high-quality equipment components; incorrect doctor blade installation—use high-quality doctor blades.

Q5: What to do when solid areas print unevenly?

A: Uneven solid printing is mainly caused by poor ink transfer. Solutions: appropriately increase pressure between the plate and substrate; use plates with lower hardness or higher compatibility; adjust ink viscosity properly and balance ink additives; enhance ink color concentration,更换 suitable ink if necessary.