What is the difference between high-temperature label adhesive and ordinary adhesive?

What scenarios require high-temperature labels?

Oven temperature indicators, automotive engine compartment labels, microwave oven panels, industrial equipment nameplates—these scenarios require labels that can withstand temperatures above 80°C. Ordinary label adhesives soften, ooze, or even lose adhesion at high temperatures, causing labels to fall off.

High-temperature label adhesive maintains stable bonding performance within the range of 80°C to 200°C through special molecular structure design. According to the GB/T 2792-2014 standard, peel strength tests at high temperatures show that the attenuation rate of high-temperature adhesive is much lower than that of ordinary adhesives.

Why are ordinary label adhesives not resistant to high temperatures?

Pressure-sensitive adhesives used in ordinary self-adhesive labels are mainly divided into two categories: acrylic and rubber.

Acrylic adhesives: Above 50°C, molecular chain segment movement intensifies, and the adhesive layer begins to soften. As the temperature continues to rise above 80°C, the adhesive layer may undergo flow deformation (commonly known as "adhesive oozing")—adhesive seeps out from the label edges, contaminating the substrate surface. Above 100°C, some acrylic polymers undergo oxidative degradation, causing the adhesive to become brittle and fail.

Rubber adhesives (natural or synthetic rubber-based) have slightly better temperature resistance, but above 100°C they also face softening and loss of adhesion. Rubber-based adhesives also accelerate aging at high temperatures, manifesting as yellowing, hardening, and cracking.

Classification and working principle of high-temperature adhesives

High-temperature label adhesives are divided into two types according to chemical system:

Silicone-based adhesive: The operating temperature range is typically -50°C to +200°C. The Si-O-Si main chain of silicone has extremely high thermal stability, maintaining elasticity even at 200°C. Silicone-based adhesive also has excellent adhesion to low surface energy materials (such as silicone rubber, PTFE), but its adhesive force is relatively weak, making it suitable for medium adhesion scenarios.

Special acrylic adhesive: Crosslink-modified acrylic adhesive can withstand temperatures from 120°C to 180°C. By introducing thermosetting crosslinking components, a three-dimensional network structure is formed at high temperatures, inhibiting adhesive layer flow. Some products use a dual-cure system (UV pre-cure + thermal post-cure) to further improve temperature resistance.

Material matching for high-temperature labels

Adhesive temperature resistance is just the foundation; the face material also needs to match the high-temperature environment:

Polyimide film: Can withstand above 260°C long-term, and up to 500°C short-term. It is the highest grade temperature-resistant face material. Commonly used for SMT circuit board labels and high-temperature industrial markings.

PET film: Can withstand around 150°C, cost-effective, suitable for most industrial high-temperature scenarios.

Ceramic fiber labels: Used for extreme high temperatures (above 500°C), mainly in steel smelting and glass manufacturing industries.

Purchasing suggestions

When selecting high-temperature labels, first confirm two data points: first, the actual operating temperature (continuous working temperature or instantaneous peak temperature); second, the adhesive surface material (stainless steel, aluminum, glass, or plastic).

For application scenarios of 100-150°C (such as oven/microwave surrounding markings), the combination of special acrylic adhesive + PET face material is sufficient.

For scenarios of 150-200°C (industrial ovens, welding process markings), silicone-based adhesive + polyimide face material is recommended.

Note: High-temperature label adhesive may become hard and brittle in low-temperature environments (< -10°C). If the product needs to span both cold chain and high temperature extreme scenarios, a specially customized wide temperature range formula is required.

LeXiang Packaging's high-temperature label solutions

LeXiang Packaging supports digital printing custom self-adhesive labels, with optional high-temperature adhesive, face materials including PET, polyimide, and synthetic paper. Digital printing requires no plate making, with small batches starting from 10 pieces, and digital proofing in 3 days.

It is recommended to first provide the actual operating temperature range and adhesive surface material, and after free sample testing, confirm the batch solution.