Nonwoven fabric by definition is fabric made by means other than weaving. There are many ways to bond fibers but they all fall within three main methods: mechanically interlock the fibers, glue the fibers together, or melt the fibers together.
- Mechanically interlocking includes needlepunch and spunlace (hydroentangled).
- Gluing the fibers includes saturate bonding and spray bonding. Usually a latex adhesive is ap-plied to the fibers and then the fabric is dried.
- Melting fibers together can only be accomplished with synthetic, thermoplastic fibers or with a blend of fibers containing thermoplastic fibers or fusable powders. These methods include thermal bonding (heat applied to the web with or without pressure) a carded web, thermobonding a spunlaid web with a calendar, thermobonding a melt blown or flash spun web with a calendar, thermobonding a carded or air laid high loft web in an oven.
There are many, many varieties of nonwoven fabric because more than one type of bonding can be applied to a fabric to enhance its properties. For instance, a needlepunched fabric can be calendered with heat and pressure and then heated with infrared to produce geotextiles. A melt blown fabric can be sandwiched between two layers of spunlaid fabric to produce a fabric called SMS which is used in hospitals.
Before nonwoven fabrics reach the consumer they are often treated with coatings to give them properties such as being waterproof, flame retardant , antimicrobial, absorbent, dyeable, and fusable. Additionally, many have chemicals applied so the fabric becomes a delivery system for furniture polish, cleaners. skin care products, auto care products, and so forth. The uses are almost endless.