I. Printing Problems
1. Misregistration
Positioning shifts during multiple print runs, leading to misaligned patterns. This may be caused by loose grippers, poor roller bearing condition, or paper deformation.
2. Color Deviation/Color Difference
Incorrect ink mixing ratio or unstable printing pressure results in colors that do not match the standard color swatch.
3. Uneven Ink Coverage
Local areas are lighter in color or mottled, often due to uneven pressure on ink/water rollers, excessive water on the plate, or inconsistent ink fountain key opening.
4. Dirty Plate/Smudging
Ink contamination in non-image areas or smudging in dark areas may be caused by hardened water rollers, excessive ink supply, or decreased hydrophilicity of the PS plate.
II. Die-cutting Problems
1. Bursting and Blind Lines
Bursting: Excessive die-cutting pressure exceeding the paper fiber's tensile strength, leading to breakage.
Blind Lines: Unwanted crease lines caused by improper steel rule selection, low paper moisture content, or incorrect fiber direction.
2. Low Die-cutting Accuracy
Large errors in manual plate making, or paper deformation after lamination/coating affecting positioning.
3. Fraying/Dusting
Dull die-cutting blades or excessive tension on the creasing rule leads to rough edges, especially common near the crease lines.
III. Surface Treatment Problems
1. Lamination Bubbling
Dust contamination in the production environment causes the film layer to separate from the paper surface.
2. Hot Stamping Misalignment
The mold is not aligned, resulting in skewed stamping position.
3. Coating Peeling
Improper surface treatment process, poor coating adhesion, and easy peeling.
IV. Cleaning and Structural Problems
1. Dirt/Odor
Unclean production environment or incomplete evaporation of ink/glue.
2. Box Bottom Deformation
Uneven moisture content in the cardboard or improper pressing pressure leads to warping and concave corners.
