Sheet structure, thermally bonded nonwoven

Nonwoven geotextiles. Nonwoven fabrics are defined as a sheet, web, or batt of directionally or randomly oriented fibres/filaments, bonded either by friction, and/or cohesion, and/or adhesion. In general, nonwoven fabric formation can be considered as a two-step process web formation (aligning the fibres with certain orientation characteristics) and bonding these fibres by mechanical, thermal, or chemical means. This two-step process has formed the classification of nonwoven structures, i.e. carded, airlaid, spunlaid, meltblown, needlepunched, hydroentangled, adhesive bonded, thermal bonded, stitch bonded, etc. Some of the important processes that are used for the manufacture of nonwoven geotextiles are discussed below. 

Nonwoven fabrics are flat, porous sheets or web structures that are made directly from separate fibers or from molten plastics or from plastic films by entangling fibers or filaments mechanically, thermally or chemically. Nonwovens can be produced from both natural and synthetic fibers or directly from polymers by a variety of techniques that involve web formation and bonding. Different polymers/fibers are more suited for one process than the other. All of the different techniques available for web formation and bonding are discussed in sufficient detail. 

---