Core Viewpoint - The article discusses the common issue of wool sweaters shrinking during washing, highlighting the reasons behind this phenomenon and offering tips for proper care and maintenance to prevent damage [1][11][15]. Group 1: Reasons for Shrinkage - Wool fibers have a structure similar to human hair, with scales on their surface that can interlock during washing, leading to shrinkage and loss of warmth [11][15]. - The primary component of wool is protein, which is affected by hydrogen bonds that can break and reform when exposed to water, especially hot water, causing the fibers to compress and shrink [17][19]. Group 2: Washing Techniques - To avoid shrinkage, it is recommended to dry clean wool sweaters instead of washing them with water, using solvents that do not disrupt hydrogen bonds [19][20]. - For washable wool, cold water should be used, and washing should be done gently to minimize physical stress on the fibers [20][22]. Group 3: Recovery from Shrinkage - If shrinkage has already occurred, using conditioner may help, but it will not restore the sweater to its original state, only provide temporary relief [22][24]. - Advances in wool treatment technology, such as plasma treatment, can reduce shrinkage rates by altering the scale structure of the fibers [26].