How to Prevent Labels from Curling in Special Temperature Conditions?
Labels curling in special temperature conditions is a common problem in many industries. This not only affects the appearance of products but can also lead to the inability to properly identify label information, and even impact the normal use of products. So, how can we effectively prevent labels from curling under special temperature conditions? This article will provide you with a systematic solution.

01 Understanding the Root Causes of “Curling”

Label curling is typically caused by the following factors:
•  Adhesive not temperature-resistant: Ordinary pressure-sensitive adhesives become soft and lose their tackiness at high temperatures, or become brittle at low temperatures.
•  Mismatch of thermal expansion coefficients between face material and substrate: Temperature changes cause different degrees of expansion and contraction between the two, creating stress that makes the edges of the label curl up.
•  Improper surface treatment: The substrate surface has oil, dust, moisture, or low surface energy (such as PP, PE materials), which affects the bonding effect.
•  Unideal application environment: The temperature during labeling is too low or too high, not reaching the optimal activation conditions for the adhesive.

02 Choosing the Right Label Materials

•  Select materials based on temperature environment:
•  High-temperature environment (>80℃):
•  Recommended face materials: Polyimide (PI), Polyester (PET), Aluminum foil composite materials.
•  Recommended adhesives: High-temperature acrylic adhesive, Silicone adhesive (can withstand above 200℃).
•  Application scenarios: Automotive engine components, Oven liners, Electronic components in reflow soldering processes, etc.

•  Low-temperature environment (<0℃, even -40℃):

•  Recommended face materials: Modified polypropylene (BOPP), Low-temperature PET, Synthetic paper.
•  Recommended adhesives: Low-temperature acrylic adhesive or rubber-based adhesive, ensuring flexibility and tackiness even in freezing conditions.
•  Application scenarios: Cold chain transportation, Frozen food packaging, Polar equipment identification, etc.

•  Environments with drastic temperature changes:

•  Key points: Choose materials with a thermal expansion coefficient close to that of the substrate and use adhesives with high initial tack + high holding power.
•  Suggestion: Conduct actual condition simulation tests to verify the label’s performance under thermal cycling.
•  Consider the surface characteristics of the substrate: Different substrates have different surface energies, and it is necessary to choose label materials and adhesives that match them. For example, for low-surface-energy plastics or metals, special adhesives are needed to ensure the label’s adhesion.

03 Correct Labeling Operations

•  Clean the substrate surface: Before labeling, it is essential to thoroughly clean the substrate surface, removing any dust, grease, or other contaminants. Otherwise, the label may curl or fall off due to an unclean surface.
•  Apply even pressure: When labeling, ensure that the label makes full contact with the substrate surface and apply even pressure. Uneven pressure distribution can easily cause the edges or bottom of the label to curl.
04 Label Storage and Transportation
•  Appropriate storage conditions: Labels should be stored in a dry environment with suitable temperature, avoiding moisture, high temperature, or low temperature. Generally, the storage temperature for pressure-sensitive labels should not be lower than 15℃.
•  Avoid compression and collision: During transportation and storage, avoid compressing or colliding with the labels to prevent damage to their structure and adhesion.

By following the above methods, you can effectively prevent labels from curling in special temperature conditions, ensuring that labels maintain good adhesion and stability in various environments.