The Science Behind Paper's Increased Vulnerability to Tears When Wet

Paper tears more easily when it's wet due to the disruption of hydrogen bonds between cellulose fibers caused by water. The cellulose fibers in paper are interlocked and bonded together through hydrogen bonds, but when water is introduced, it forms its own hydrogen bonds with the cellulose, blocking the fibers from binding. This weakens the paper's structure, making it easier to tear. Different paper products have varying responses to water due to the additives included during the papermaking process. Dry strength additives like potato starch can enhance the strength of paper, but even toughened cardboard can lose its strength when exposed to moisture as starch dissolves in water.