When the paper is put into the cup, because the surface area of the paper is relatively large, it forms a relatively large contact area with the surrounding air, so that the air can form a thin gas layer on the surface of the paper and form a protective layer to prevent moisture from infiltrating into the paper.
Paper itself has certain water absorption. When water drops drop on the surface of the paper, water will be absorbed by the paper, so it will not drop to the bottom of the cup. It should be noted that this situation only applies to a small amount of water droplets. If there is too much water or too long, the paper will still get wet.
Matters needing attention in using paper cups
1. Pay attention to the quality of cups: poor quality paper cups may break or leak, so check the quality of cups before use.
2. Avoid reuse: Paper cups are disposable and cannot be reused to avoid cross-infection.
3. Don't fill the water too full: Don't fill the paper cup with water too full, so as not to deform the cup or overflow the water.
4. Avoid hot drinks: Hot drinks in paper cups may deform or burn your fingers, and are not recommended for hot drinks.
5. Pay attention to handling: the used paper cups should be handled in time and put into the trash can to avoid being discarded at will.