Common Defects of Self-Adhesive Labels: 4 Must-Know Points
In the production and usage of self-adhesive labels, various defects can occur, which not only affect the aesthetics of the labels but also impact their functionality. This article will systematically outline the common defect types of self-adhesive labels and provide corresponding preventive and resolution suggestions.

I. Printing Defects

1.  Misregistration
•  Description: In multi-color printing, colors fail to align accurately, resulting in blurred images, ghosting, or color deviations.
•  Causes: Insufficient equipment precision, improper material tension control, significant changes in environmental temperature and humidity.
•  Solutions: Regularly calibrate printing machines, control workshop temperature and humidity, select face materials with high stability.

2.  Obvious Color Difference

•  Description: Inconsistent colors within the same batch or between different batches of labels.
•  Causes: Differences in ink batches, fluctuations in printing parameters, different light source observation conditions.
•  Solutions: Establish standard color samples, use special color inks, strengthen quality control during the process.

3.  Ink Irregularity/Leak Printing

•  Description: Local areas have light ink color, broken lines, or complete absence of ink.
•  Causes: Worn printing plates, improper doctor blade pressure, poor ink flowability.
•  Solutions: Replace printing plates in time, optimize the doctoring system, select suitable ink.

II. Material and Structural Defects

4.  Creasing or Curling
•  Description: Labels develop wrinkles or have edges curling up during rewinding or labeling.
•  Causes: Mismatched thermal expansion and contraction coefficients between liner and face material, uneven coating, humid storage environment.
•  Solutions: Select composite materials with good compatibility, control coating process, maintain dry storage.

5.  Adhesive Overflow (Seepage)

•  Description: Adhesive seeps out from the edges of the label, contaminating equipment or product surfaces.
•  Causes: Excessive adhesive amount, strong adhesive fluidity, die-cutting too deep to damage the liner.
•  Solutions: Precisely control the adhesive amount, optimize die-cutting depth, choose adhesive with strong cohesive strength.

6.  Waste Strip Breakage or Label Removal

•  Description: After die-cutting, the waste edge cannot be smoothly removed and even takes the finished label away.
•  Causes: Insufficient or excessive die-cutting pressure, insufficient liner strength, unreasonable waste removal angle design.
•  Solutions: Adjust die-cutting parameters, select high tensile strength liner, optimize waste removal path.

III. Adhesion and Usage Defects

7.  Insufficient Adhesion (Label Falling Off)
•  Description: Labels easily fall off after being attached, especially in low-temperature, humid, or curved surface environments.
•  Causes: Incorrect adhesive selection, oil contamination on the surface to be labeled, insufficient labeling pressure.
•  Solutions: Choose the appropriate adhesive type according to the application scenario (such as rubber-based, acrylic-based), clean the surface to be labeled, ensure the labeling equipment pressure meets the standard.

8.  Residue or De-lamination

•  Description: Adhesive residue remains after tearing off the label, or the adhesive layer separates from the face material.
•  Causes: Adhesive aging, high-temperature environment accelerates adhesive migration, poor adhesion of face material coating.
•  Solutions: Use aging-resistant adhesive, avoid prolonged exposure to sunlight, test the compatibility of face material and adhesive.

9.  Static Electricity Attracting Dust

•  Description: Labels attract dust due to static electricity, affecting aesthetics and labeling accuracy.
•  Causes: Static electricity generated during high-speed printing/cutting, dry environment.
•  Solutions: Install static eliminators, control workshop humidity (recommended 40%–60% RH).

IV. Other Issues

10.  Poor Weather Resistance
•  Description: Fading, lifting edges, adhesive failure when used outdoors.
•  Solutions: Use UV-resistant ink, apply film protection, adopt weather-resistant adhesive and face materials (such as PET, synthetic paper).

11.  Barcode/QR Code Recognition Failure

•  Description: Scanning devices fail to read information.
•  Causes: Insufficient contrast, dimensional errors, blurred printing, reflective interference.
•  Solutions: Follow GS1 standards, conduct barcode verification tests, avoid using highly reflective materials.