During long-term storage, the color of blister heat seal packaging color cards is affected by multiple factors, including material properties, environmental conditions, and process control. Their stability and durability require scientific storage and material optimization to ensure. As a core tool for color standardization, color cards need to maintain color accuracy over the long term. However, in actual storage, factors such as oxidation, light exposure, temperature and humidity fluctuations, and material aging can cause color deviations, affecting the reliability of product color matching.
The weather resistance of the material itself is fundamental to the long-term stability of the color card. blister heat seal packaging color cards typically use plastic substrates such as PET, PVC, or PS. PET is the preferred choice for high-end applications due to its high transparency, high strength, and recyclability, but its high melting point requires special processing. PVC is widely used due to its high toughness and ease of heat sealing, but it may produce chlorine gas when burned, limiting its environmental friendliness. PS, while low in cost, has poor toughness and is flammable, and is mostly used in industrial pallets. These materials may experience color fading due to changes in their molecular structure during long-term storage. For example, PVC is prone to yellowing under light, while PET may absorb moisture and deform in high-temperature and high-humidity environments, indirectly affecting color reproduction.
Environmental conditions have a significant impact on the color of color cards. High temperatures accelerate the oxidation reaction of the plastic substrate, causing the color to darken or yellow, and may also soften the heat-sealing layer, leading to adhesion or deformation. Low temperatures may make the material brittle, causing surface cracks and affecting gloss. Light is another key factor; ultraviolet rays can damage the plastic molecular chains, causing the color to gradually fade, especially light or bright color cards. Furthermore, excessive humidity can cause the material to absorb moisture and expand, resulting in surface fogging or mold, further obscuring the original color; while excessively low humidity may cause static electricity to attract dust, contaminating the color card surface.
Process control and storage methods directly affect the long-term performance of color cards. During production, unstable raw material quality or improper heating temperature control may lead to deviations in the initial color of the color card, creating potential problems for subsequent storage. When storing, color cards should not be stacked with heavy objects to prevent deformation or scratches due to pressure; they should also be kept away from chemicals such as solvents, acids, and alkalis to prevent corrosion of the surface coating or penetration into the substrate. Categorized storage and regular inspection are equally important. Color cards of different materials or colors should be stored separately to prevent color migration. Regular inspections can promptly detect problems such as discoloration and cracking, facilitating early replacement.
Protective measures against color changes should be implemented throughout the entire lifecycle of the color cards. During the production stage, materials with excellent weather resistance should be selected, such as PET with added UV absorbers or specially treated PVC, to enhance anti-aging capabilities. Simultaneously, the heat-sealing process should be optimized to ensure tight seals and prevent moisture intrusion. During storage, color cards should be placed in a dry, ventilated, and dark environment, with the temperature controlled below 20 degrees Celsius and humidity maintained at around 50%. Desiccants or desiccant boxes can be used to further isolate moisture. In addition, using opaque packaging materials or light shields can reduce direct sunlight and slow down fading.
In practical applications, the long-term stability of color cards also needs to be evaluated in conjunction with the usage scenario. For example, color cards used for cosmetic packaging must meet higher environmental standards to avoid the generation of harmful substances due to material degradation; while color cards used for electronic products must have anti-static properties to prevent dust accumulation from affecting color judgment. For color cards stored long-term, it is recommended to establish a standard color card library and regularly compare them with new color cards. Color deviations should be quantified using equipment such as spectrophotometers to ensure color consistency.
The long-term color changes of blister heat seal packaging color cards are the result of the combined effects of materials, environment, and processes. By selecting high-quality materials, optimizing production processes, scientific storage, and regular maintenance, the lifespan of color cards can be significantly extended, ensuring their accuracy in color matching and providing a reliable basis for packaging design, production, and quality control.
