Non woven fabrics and spunbonded fabrics are subordinate. Non woven fabric is a kind of fabric formed without spinning and weaving.

Characteristics and applications of non-woven fabrics. Durability, disposable. Insulated, conductive. Softness, rigidity. Fineness and expansibility. Isotropic, anisotropic.

The estimate worldwide volume of nonwovens in 1991 was 3.5 billion pounds. North America accounts for just below 50% of this output, 29% is the share of western Europe and the rest of the world accounts for the remaining 20%.

In many respects, air and other gas filtration represent the less exciting part of the filtration business, by comparison with liquid filtration. Certainly it is much smaller: “dry” filtration makes up only around 15 % of the total filtration market, about one sixth that of “wet” filtration.