Fibers are often used in the manufacture of other materials. The strongest engineering materials are generally made as fibers, for example carbon fiber and Ultra-high-molecular-weight polyethylene.
Synthetic fibers can often be produced very cheaply and in large amounts compared to natural fibers, but for clothing natural fibers can give some benefits, such as comfort, over their synthetic counterparts. Nonwoven textiles are made with long pieces of fiber which are then bonded together by either chemical, mechanical, heat or solvent treatment. Nonwovens may lack some of the strength of their woven counterparts, but they more than make up for that with their lost cost to manufacture and disposability.
The mechanical properties of nonwovens characterize the response of the material to applied forces and deformations. These are often considered the most important of the physical properties since they contribute both to performance of the finished product during use and the behavior of the product during processing. The physical properties of a nonwoven are defined in terms of its dimensions, weight, density, and other properties.
Some of the properties which characterize the physical properties are:
- Density
- Absorption
- Optical properties
- Dimension, length, width and caliper (thickness)
- Frictional properties
- Swelling
- Electrical properties
- Thermal properties