1. Determine the specific temperature range of its heat resistance. The temperature resistance of labels made of different materials varies greatly. You need to first determine the maximum temperature of your application scenario:
Regular high temperature (70-120℃): For applications such as electronic device casings and industrial cleaning lines, PET labels are sufficient, with a typical temperature resistance of -20℃ to +120℃.
Medium high temperature (100-320℃): For applications such as circuit board reflow soldering and solder bath processes, PI (polyimide) heat-resistant labels are required, which can withstand temperatures above 300℃ for extended periods.
Ultra-high temperature (above 320℃): For applications such as steel smelting and ceramic firing, polyimide or ceramic-based labels are required. Some products can withstand temperatures up to 1000℃.
✅ Core conclusion: PET labels are suitable for general high-temperature environments, while PI material is the preferred choice for extreme high-temperature scenarios such as electronics manufacturing.
2. High Temperature Resistance Test Methods
Tests are conducted under simulated real-world conditions to ensure reliable label operation at high temperatures:
Constant Temperature Baking Test
Steps: Affix the label to the target material surface and place it in an oven at a set temperature (e.g., 80℃, 120℃, 150℃) for 30 minutes to several hours.
Acceptance Criteria: No bubbling, no edge curling, no peeling; printed content shows no discoloration or blurring.
Heat Cycling Test
Applicable Scenarios: Environments with drastic temperature changes (e.g., outdoor equipment, automotive parts).
Method: Cycle between -20℃ and +80℃ three times, maintaining the temperature for one hour each time, and observe the label's condition.
Acceptance Criteria: No cracking, no delamination, stable adhesion.
Simulated Real-World Conditions
For circuit boards, a reflow soldering process can be simulated (peak temperature 260℃, lasting 10 seconds) to observe whether the label carbonizes or peels off. For example, when used for cleaning metal cans, a process combining 60℃ hot water immersion and high-temperature drying is used to verify the label's stability throughout the process.
3. Key Materials and Process Reference
Face Material Selection:
PET: Temperature resistant up to 120℃, cost-effective, suitable for most industrial scenarios.
PI (Polyimide): Temperature resistant above 300℃, golden yellow or black, specifically used for marking electronic components.
Adhesive Type: Acrylic pressure-sensitive adhesive is used, maintaining adhesion at high temperatures and minimizing residue.
Printing Method: Thermal transfer + resin ribbon is used to ensure that the graphics and text do not fade or peel off under high-temperature conditions.
✅ Comprehensive Judgment: A qualified high-temperature waterproof label must maintain structural integrity, strong adhesion, and legible information within the specified temperature range, and the material and process must match the actual application scenario.
