Nonwoven fabrics are broadly defined as sheet or web structures bonded together by mechanical entanglement, chemical, thermal, or other means. Unlike traditional fabrics, the fibers are not first converted to yarn and then woven or knitted into a fabric. Instead, a porous sheet or web is made directly from separate fibers. The process of manufacturing nonwovens is made up of two basic steps; 1) web forming, where loose fibers are laid out on a moving porous belt or drum to create a uniform sheet, and, 2) web bonding, where an adhesive or entanglement process is applied to bond the laid out fibers together to create a stable web, or sheet, of material. This module covers some of the different web forming processes.
Learning Objectives
- List the three general classifications of web forming used to manufacture nonwovens
- Describe the meaning of fiber opening
- Describe the purpose of fiber carding
- Describe the advantages and disadvantage of air laid forming
- Describe the advantages and disadvantage of wet laid forming
- List the five major steps of spunbond forming
- List some of benefits that can be achieved with bi-component fibers
- Describe the main difference between the spunbond and meltblown processes