Nonwoven textiles are those which are neither woven nor knit, for example felt. Nonwoven are typically not strong (unless reinforced by a backing), and do not stretch. They are cheap to manufacture. Nonwoven fabric is manufactured by putting small fibers together in the form of a sheet and then binding them either mechanically (as in the case of felt), with an adhesive, or by interlocking them with serrated needles such that the inter-fiber friction results in a strong fabric.
Today, nonwoven materials are manily produced from man-made fibers. Two synthetic polymers dominated the market are polypropylene and polyesters (mainly PET). There are two kind of nonwoven, staple nonwoven and spun-laid nonwoven, which produced by different processes.
Thermobonded nonwoven (staple nonwoven), are maid mainly by two step process. First fibers are cut to a few centimeter length, and put into bales. These bales are then dispersed on a conveyor belt and the fibers are spread in a uniform web by carding. In the second step nonwoven are calendaring through heated rollers, to give mechanical resistance.