In a wet hair pull test, how much can wet hair stretch relative to its length?

In a wet hair pull test, how much can wet hair stretch relative to its length?

• A. 40% - 50%
• B. 10% - 20%
• C. 60% - 70%
• D. 20% - 30%

Answer: (A)

When hair is tested in the wet state, its elasticity increases in terms of how much it can stretch before breaking, because water acts as a plasticizer that makes the keratin more mobile. As a result, a typical wet hair strand can elongate about 40–50% of its original length before it breaks. For example, a 10 cm strand could stretch to roughly 14–15 cm under the pull test before snapping. It’s important to note, though, that while it can stretch more, wet hair is weaker and requires less force to break. This balance helps evaluate how well hair can recover after stretching and indicates overall elasticity and potential damage.

When hair is tested in the wet state, its elasticity increases in terms of how much it can stretch before breaking, because water acts as a plasticizer that makes the keratin more mobile. As a result, a typical wet hair strand can elongate about 40–50% of its original length before it breaks. For example, a 10 cm strand could stretch to roughly 14–15 cm under the pull test before snapping. It’s important to note, though, that while it can stretch more, wet hair is weaker and requires less force to break. This balance helps evaluate how well hair can recover after stretching and indicates overall elasticity and potential damage.