Ink discoloration and fading is a common phenomenon, which is caused by the denaturation of ink properties. Let's take a look at what factors can cause ink denaturation.
1. Caused by ink drying: The ink color of the newly printed product is still relatively dark, but after drying for a while, the color of the ink becomes lighter, which is caused by the penetration of the ink and the conjunctiva during the drying process. The thicker the ink film that sunlight passes through, the more saturated the reflected color, and the lighter the ink layer after drying, the lighter the color. If you want to keep the ink color thicker after drying, you only need to thicken the ink layer when printing.
2. Caused by light resistance: Any ink will change color to varying degrees under light, so the abrasion resistance of the ink should be considered when adjusting the ink.
3. Caused by paper quality: Newsprint and kraft paper are highly absorbent, and the ink will be absorbed by the paper. Therefore, the absorption of ink by paper and the penetration of ink into paper will cause discoloration.
4. Caused by heat resistance: the temperature resistance of the ink is 120°C, and high temperature will cause the ink to change color when heated.
5. Caused by the proportion of alcohol: When the proportion of alcohol added is too large, it is easy to cause gelation. If the proportion is too small, it will also change color, so it is better to control the proportion of alcohol reasonably.
6. Caused by intolerance to alcohol: The effect of alcohol moistening: 1. To ensure the spreading performance of the layout. 2. It is volatile and reduces the absorption of paper. 3. Volatilize and cool down to ensure the fluidity of the ink. If the product changes color after being wetted by alcohol, it means that the ink has poor alcohol resistance.
7. Caused by paper chemical substances: The chemical substances added to the paper affect the pH of the paper, and the pH of the paper will affect the color of the ink, especially the light-colored ink. For example: If iron compounds are added to paper, it is easy to make light-colored ink brown.