Sustainable Packaging Materials: Things You May Want to Know

When using pressure-sensitive adhesive (PSA) materials in labels, various issues may arise during printing, application, and storage.  Below are the most common problems and their corresponding solutions.

1.  Printing Issues

Problems:

● Ink adhesion issues: The ink may not adhere well to the surface of the label, leading to smudging or fading.

● Slow drying time: Certain PSA materials, especially those with glossy or coated surfaces, may slow down ink drying.

● Color shift or inconsistency: Different surface coatings and ink absorption rates can lead to color variations.

Solutions:

✅ Use UV or solvent-based inks designed for PSA materials to improve adhesion and drying speed.

✅ Conduct surface treatment (e.g., corona treatment or primer coating) to enhance ink adhesion.

✅ Use color calibration techniques to maintain color consistency.

2.  Adhesion and Bonding Issues

Problems:

● Poor initial tack: The label does not adhere well immediately after application.

● Label lifting or peeling: The edges of the label may lift, especially on curved surfaces or rough materials.

● Incompatibility with certain surfaces: PSA labels may not stick well to low-energy surfaces like plastic, powder-coated metals, or silicone-treated surfaces.

Solutions:

✅ Choose the correct adhesive type (e.g., permanent, removable, high-tack) based on the application surface.

✅ Increase pressure during application to improve bonding strength.

✅ Use adhesion promoters or primers for challenging surfaces.

3.  Label Curling and Warping

Problems:

● Curling during application: The edges or corners of the label lift before or after application.

● Warping over time: The label may deform due to temperature or humidity changes.

Solutions:

✅ Use dimensional-stable materials that resist temperature and humidity fluctuations.

✅ Store PSA labels in a temperature-controlled and humidity-controlled environment.

✅ Ensure proper release liner tension during label dispensing to avoid excessive curling.

4.  Die-Cutting and Processing Issues

Problems:

● Labels tearing or not cutting cleanly: The adhesive may ooze out, affecting the die-cutting process.

● Release liner breakage: Thin or weak liners may break during high-speed dispensing.

● Difficulty in label dispensing: Labels may not release smoothly from the liner.

Solutions:

✅ Use die-cutting blades designed for PSA materials to ensure clean cuts.

✅ Select a proper liner material that is compatible with the label dispensing process.

✅ Store labels in a dry environment to prevent adhesive migration and liner issues.

5.  Temperature and Environmental Issues

Problems:

● Label falls off in extreme temperatures: Some adhesives lose their bonding strength in hot or cold conditions.

● Adhesive failure in humid conditions: Moisture can reduce adhesion, leading to peeling or bubbling.

Solutions:

✅ Select temperature-resistant adhesives for extreme conditions (e.g., freezer-grade adhesives for cold environments).

✅ Choose moisture-resistant adhesives for humid conditions.

✅ Store labels in controlled environments before application to ensure optimal performance.

6.  Surface Contamination and Compatibility Issues

Problems:

● Oil, dust, or moisture on the surface reduces adhesion.

● Adhesive reacts with certain surfaces, leading to label discoloration or residue.

Solutions:

✅ Clean the surface with alcohol or a suitable solvent before applying the label.

✅ Use low-residue adhesives if the label needs to be removed cleanly.

✅ Test the adhesive on the surface before large-scale production to ensure compatibility.

7.  Regulatory and Compliance Issues

Problems:

● Food safety concerns: Labels used on food packaging must meet regulatory standards.

● Recycling and sustainability issues: Some adhesives may hinder the recyclability of packaging materials.

Solutions:

✅ Use FDA- or EU-compliant adhesives for food packaging applications.

✅ Choose eco-friendly, recyclable, or biodegradable PSA materials to meet sustainability goals.