Glue-sprayed cotton, also known as gunning cotton, is a kind of nonwoven fabric. The principle of structure formation of rubber-sprayed cotton is to spray adhesive on both sides of fluffy fiber layer. Because there is a certain pressure when spraying and the suction force when the lower part absorbs liquid in vacuum, the adhesive can also penetrate into the fiber layer. After the fiber layer is sprayed with adhesive, it is dried and cured, so that the cross points between fibers are bonded, but the unbonded fibers still have considerable freedom. At the same time, there are many gaps containing air in the three-dimensional network structure. Therefore, the fiber layer has a porous and high fluffy warm-keeping effect.
Some polar fleece fabrics are mixed with polyester fibers. I've heard of "ice silk". Some so-called ice silk on the market is mixed with polyester fiber, so the warmth retention of polar fleece is limited. Moreover, the price of polar fleece is relatively high, and the quality of products on the market is uneven, which may lead to inferior fabrics and asthma and other diseases.