Nonwoven manufacture starts by the arrangement of fibres in a sheet or web. The fibres can be staple fibres packed in bales or filaments extruded form molten polymer granules.
Four basic methods are used to form a web. The nonwoven is usually referred to by one of these technologies.

• Drylaid
• Airlaid
• Spunlaid/Meltblown
• Wetlaid

Drylaid

Carding is a mechanical process, which starts with the opening of bales of fibres which are blended and conveyed to the next stage by air transport. The fibres are then combed into a web by carding machine, which is a rotating drum or series of drums covered in fine wires or teeth. The precise configuration of cards will depend on the fabric weight and fibre orientation required. The web can be parallel-laid, where most of the fibres are laid in the machine direction, or they can be random-laid. Typical parallel-laid carded webs result in good tensile strength, low elongation and low tear strength in the machine direction and the reverse in cross direction. Relative speeds and web composition can be varied to produce a wide range of properties.


Airlaid

The second method of drylaying is airlaying. In airlaying, the fibres, which can be very short, are fed into an air stream and from there to a moving belt or perforated drum, where they can form a randomly oriented web. Compared with carded webs, airlaid webs have a lower density, a greater softness and an absence of laminar structure. Airlaid webs offer great versatility in terms of the fibre blends that can be used.

Spunlaid/Meltblown

In this process polymer granules are melted and molten polymer is extruded through spinnerets. The continuous filaments are cooled and deposited on to a conveyer to form a uniform web. Some remaining temperature can cause filaments to adhere to one another, but this cannot be regarded as the principal method of bonding.
The spunlaid process (sometimes known as spunbonded) has the advantage of giving nonwovens greater strength, but raw material flexibility is more restricted.
Co-extrusion of second components is used in several spunlaid processes, usually to provide extra properties or bonding capabilities.
In meltblown web formation, low viscosity polymers are extruded into a high velocity air stream on leaving the spinneret. This scatters the melt, solidifies it and breaks it up into a fibrous web.

Wetlaid

Dilute slurry of water and fibres is deposited on a moving wire screen and drained to form a web. The web is further de-watered, consolidated, by pressing between rollers and dried. Impregnation with binder is often included in a later stage of the process.
Wetlaid web forming allows a wide range of fibre orientations ranging from near random to near parallel. The strength of the random oriented web is rather similar in all directions in the plane of the fabric. A wide range of natural, mineral, synthetic and man-made fibres of varying lengths can be used.