Whether rubber roller or PU – if wrinkles occur in gravure printing, the causes are usually technical in nature, yet often difficult to pinpoint.
👉 Here’s an overview of the most common causes – and what helps against them:
❌ Excessive nip pressure
→ Heat distortion on the roller, uneven circumferential speed
✅ Start with a low nip pressure and make sure that the nip of the pressure profile is uniform from right to left. This is especially important for off-center print formats.
❌ Insufficient web tension at the infeed
→ Paper does not lie flat, starts to buckle
✅ Always increase web tension progressively from the rear infeed group towards the outfeed. Keep in mind that the cylinders become slightly larger in diameter from back to front – the progressive cylinder staggering ensures clean web guidance.
❌ Excessive web tension at the outfeed
→ Pulls sideways if the nip is not correctly aligned
✅ Precisely align the nip, and adjust web tension so the web runs straight from the printing unit into the dryer.
❌ Humid environment + insufficiently dried web
→ Water pockets, unstable running, inconsistent formats
✅ Ensure optimal drying. Residual paper moisture must be consistent across the entire web width from right to left.
❌ Moisture wrinkles caused by excessive water content
→ Especially with waterborne SH-coatings, if the formulation contains too much water
✅ Check the formulation, optimize the water content, and adjust drying capacity accordingly.
🧠 Conclusion:
Pressing wrinkles are rarely the result of a single error – almost always they arise from a disturbed interaction of tension, temperature, ink laydown, drying, and mechanics.
💡 Good to know: With our resisco products and solutions, we directly address this issue – contributing to significantly smoother production runs.