High temperature environments can have a significant impact on the material of tamper-evident labels. For paper labels, high temperatures may cause the paper to become brittle, yellow, or even curl and deform. This not only affects the appearance of the label, but may also reduce the fit between the label and the product surface, making it prone to bubbles or warping, thereby weakening the label's tamper-evident performance. For plastic labels, high temperatures may soften them, change their physical properties, and make them easier to be removed or damaged. Some plastic labels may also shrink at high temperatures, causing the label to deform and fail to fully cover the product surface, providing an opportunity for criminals.
High temperatures change the viscosity of the glue. Generally speaking, the viscosity of the glue decreases in a high temperature environment, resulting in a weakened adhesion between the label and the product surface. This makes the label easier to remove, and even if it is re-pasted, it is difficult to restore the original adhesion effect, so it cannot effectively play a tamper-evident role. In addition, high temperatures may also cause the glue to seep out, contaminating the product surface, affecting the appearance and quality of the product. If the glue oozes out and then dries, it may form lumps or crystals, further destroying the fit between the label and the product surface and reducing the anti-tampering performance.
High temperatures may damage the anti-counterfeiting information on the label. For example, some anti-counterfeiting patterns or texts printed with thermosensitive inks may change color or fade at high temperatures, resulting in the inability to properly identify the anti-counterfeiting information. For smart tamper-evident labels containing electronic components or chips, high temperatures may affect the performance of their electronic components, causing the chips to fail to work properly, resulting in the failure of the anti-counterfeiting function. In addition, high temperatures may also weaken the fluorescence intensity of some invisible anti-counterfeiting information on the label, such as patterns printed with fluorescent inks, after excitation, increasing the difficulty of identifying anti-counterfeiting information.
Humid environments also have adverse effects on the material of tamper-evident labels. Paper labels easily absorb moisture, become damp and soft, and have reduced strength. In this case, the label is more likely to be torn or damaged, and loses its due anti-tampering ability. Moreover, damp paper is also prone to mold growth, resulting in mildew spots on the label surface, affecting the appearance and readability of the label. For plastic labels, if they are in a humid environment for a long time, water droplets or water mist may appear on their surface, affecting the bonding effect between the label and the product surface. It may also accelerate the aging of the plastic and make it brittle and fragile.
Humidity can change the viscosity of the glue. On the one hand, water will dilute the glue, reduce its viscosity, and reduce the adhesion between the label and the product surface. On the other hand, a humid environment can easily cause the glue to absorb too much water and undergo a hydrolysis reaction, destroying the chemical structure of the glue, further reducing its viscosity or even completely losing its viscosity. In this way, the label can easily fall off the surface of the product. Even if it does not fall off, it will not leave obvious signs of damage after being peeled off due to insufficient viscosity, and the purpose of anti-tampering cannot be achieved.
A humid environment may affect the clarity and integrity of the anti-counterfeiting information on the label. For anti-counterfeiting patterns or texts printed with water-based inks, humidity may cause the ink to smudge and diffuse, making the pattern or text unclear, affecting the anti-counterfeiting effect. For some labels that use physical properties to prevent counterfeiting, such as anti-counterfeiting labels that use the principle of optical color change, humidity may change the optical properties of the label surface, making the color change effect of the anti-counterfeiting pattern unclear or unable to display normally. In addition, humidity may also cause rust and corrosion of the metal anti-counterfeiting lines or patterns on the label, reducing its anti-counterfeiting value.
In a comprehensive environment of high temperature and humidity, the performance of tamper-evident labels is more complicated and serious. Not only are labels easily tampered with due to material deformation and reduced glue viscosity, but the anti-counterfeiting information may also be completely ineffective due to the dual effects of high temperature and humidity. In order to cope with these problems, it is necessary to select label materials and glues with high temperature and humidity resistance, and use special printing processes and protective coatings to protect the anti-counterfeiting information. At the same time, during the storage and transportation of products, try to avoid exposing labels to high temperature and humidity environments, and take appropriate moisture-proof and heat-insulating measures to ensure that tamper-evident labels can function normally and protect the safety and authenticity of products.
