Fabric is constantly being stretched and stressed in the process of being made. When fabric is heated, the stress relaxes out, causing the fabric threads/yarn to shorten. Applying heat is the most successful way to shrink almost all kinds of fabric. Heat is even more effective when combined with moisture and movement. This is known as consolidation shrinkage. It releases the tension in cotton, denim, and to some extent polyester threads, reshaping the garment. The longer the fabric can be placed in these conditions, the more it's likely to shrink.  Remove the clothing right after the wash cycle. Do not air dry. Air drying cools off fabric very quickly, making it less likely to shrink. High heat is what's needed to cause cotton, denim, and polyester to contract. Just as hot water causes fabric to condense, so does hot air.  Choose the longest cycle available. Agitation (such as the spinning of the dryer) may help with shrinkage. As the threads receive heat and undergo movement, they shrink. Leave the fabric in the dryer until it is completely dry. Hanging it to air dry will cool the fabric too quickly. In the case of denim, it may also cause it to stretch. Polyester is a synthetic fiber, and more difficult to shrink than most other fabrics. It is durable and can go through many cycles without damage.
قم بضبط حرارة الغسالة على الوضع الساخن. قم بغسل الملابس في أطول دورة غسيل ممكنة. قم بتجفيف الملابس في دورة تجفيف ساخنة. قم بتكرار دورات الغسيل والتجفيف للبولستر إذا لم ينكمش بالقدر الذي تريده.