Why Do Frozen Labels Easily Fall Off? Adhesive Selection Is Key

The Real Pain Points of Frozen Label Detachment

Labels on packaging of quick-frozen dumplings, ice cream, and frozen seafood frequently experience curling or even falling off. Food companies face not only product appearance issues—products lacking compliant labels may be removed from shelves, and unclear label information can lead to consumer complaints.

A client producing quick-frozen dumplings reported that after switching to freezer-grade adhesive labels, the label detachment rate dropped from 15% to within 0.5%. The core of this difference lies in the low-temperature adaptability of the adhesive.

What Happens to Ordinary Glue at Low Temperatures?

The adhesion of glue comes from the intermolecular forces of polymer chains. At room temperature, polymer chains have sufficient mobility to fully wet the surface of the substrate, generating bonding strength.

When the temperature drops below 0°C:

First, the movement of glue polymer chains is restricted, causing adhesion to drop sharply. Ordinary acrylic adhesive may lose over 60% of its initial tack at -5°C.

Second, the adhesive layer becomes hard and brittle, easily fracturing and detaching when subjected to packaging compression or bending. Temperature fluctuations caused by frequent refrigerator door openings amplify this issue.

Third, condensation water forms on the surface of frozen food packaging during the cold chain. Water molecules create an isolation layer between the adhesive and the substrate, further weakening the bond.

Technical Principles of Freezer-Grade Adhesive

Freezer-grade adhesive solves low-temperature bonding issues through three technical approaches:

First, selecting polymer monomers with low glass transition temperature (Tg) ensures that the adhesive chains still have sufficient mobility below -20°C. The Tg of freezer-grade adhesive is typically below -30°C, while that of ordinary acrylic adhesive is around -10°C to 0°C.

Second, increasing the cohesive strength of the adhesive layer. Freezer-grade adhesive maintains flexibility at low temperatures while having sufficient internal strength, so it does not break due to packaging bending.

Third, adding anti-condensation components to the formula to reduce moisture intrusion into the bonding interface. Some freezer-grade adhesives also possess a certain 'low-temperature wetting' ability, allowing them to closely adhere to the substrate surface even when labeling in a freezing environment.

Material Matching for Freezer-Grade Adhesive Labels

Adhesive is only part of the solution. Face material selection is equally critical. Recommended face materials for frozen labels include:

Synthetic paper: PP or PE-based synthetic paper, resistant to low temperatures down to -40°C, waterproof and oil-proof, does not break during die-cutting, is the mainstream face material for frozen labels. Cost is between coated paper and PET.

PET film: Best low-temperature and weather resistance (down to -70°C), high strength, but feels stiffer and is more expensive. Suitable for cold chain scenarios requiring extremely high durability.

Coated paper not recommended: Coated paper becomes more brittle at low temperatures, and die-cut edges are prone to breaking; paper fibers also deform and curl after absorbing moisture. If coated paper must be used, lamination is recommended to increase moisture resistance.

Key Details in Labeling Operations

Even with the correct freezer-grade adhesive and face material, improper operation can still cause detachment:

First, the product surface must be dry during labeling. Frozen food surfaces quickly develop condensation after leaving cold storage; labeling should be completed after packaging is sealed but before entering cold storage.

Second, the labeling environment temperature should preferably be above 10°C. The initial tack of the adhesive is compromised at low temperatures; it is recommended to label in a room-temperature workshop and then transfer to cold storage.

Third, apply sufficient pressure after labeling to ensure the adhesive fully wets the substrate surface. Especially for labels on corrugated boxes, ensure adequate pressure.

LeXiang Packaging's Cold Chain Label Solution

LeXiang Packaging offers custom adhesive label services, with both digital printing and flexographic printing processes available with freezer-grade adhesive. Minimum order quantity is 10 pieces, with samples ready in 3 days. Face materials include synthetic paper, PET, or laminated coated paper, and the adhesive is formulated according to the actual usage temperature.

For food companies with export needs, GB 4806 food safety compliant labels can also be provided. It is recommended to first send samples for testing, confirming the bonding effect in a simulated cold chain environment before mass production.