To distinguish nonwovens from papers, a wet laid material will be defined a nonwoven if:

• More than 50%, by mass, of its fibrous content is made up of fibers (excluding chemically digested vegetable fibers) with a length to diameter ratio greater than 300; or

• More than 30%, by mass of its fibrous content is made of fibers in “a” above and meet one or both of the following criteria:

  • Length to diameter ratio of more than 600

  • The density of the fabric is less than 0.4 g/cc