The cause of the wool is not falling when it rains

If you put a sweater in the washing machine, it may shrink. So why is wool, basically wool, not shrinking when it rains? The main reason is friction.

Like the fur of all mammals, woolen yarns are coated by numerous small scales overlapping each other. Scales cause fibers to slide in this direction more easily than the other. This also explains that if you use a hand to stroke a hair, you will find that the claw from the leg to the hair is easier than the opposite direction.

When sheep stand in the rain, the hairs in their thick coats also bulge and scales soft.

When the sweater is put into the washing machine and kneaded, this one-sided scale becomes a problem. When the wool fibers rub against each other, the scales are like small hooks that only allow wool fibers to move in one direction.

Water makes things worse. Water makes wool fibers bulge, making them closer together and softening scales enough to make them easier to get together but not soft enough to slip through.

Heat also helps the woolen strands become more interconnected by being more malleable and exposed, similar to the more collided spaghetti fibers than the hard fibers, which live.

In the process of washing and drying, millions of small hooks on thousands of yarns of sweaters make wool increasingly pressed and the shirt shrinks.

When sheep stand in the rain, the hairs in their thick coats also bulge and scales soft. But the wool was not so kneaded that the fibers caught together and the coat shrank.