According to the national standard GB/T 5709-1997, non-woven materials, commonly known as non-woven fabrics, are sheets and fibers made by combining fibers arranged in a specified direction or randomly through friction, entanglement or bonding, or a combination of these methods. Nets or pads (excluding paper, woven fabrics, tufted fabrics, stitched fabrics with stitched yarns, and wet-laid felts). The fiber used can be natural fiber or chemical fiber; it can be short fiber, filament or fibrous material formed on the spot. In order to distinguish between wet-laid nonwoven materials and paper, it is also stipulated that in its fiber composition, fibers with an aspect ratio greater than 300 account for more than 50% of the total mass, or fibers with an aspect ratio greater than 300 account for more than 30% of the total mass. But the density is less than 0.4g/cm3, it belongs to non-woven material, otherwise it is paper.
