Bonding is a crucial step in the production of nonwoven fabrics, as it stabilizes the loose fiber web, giving it cohesion and strength. There are various methods for bonding nonwoven fabrics, each with its advantages and suitability for specific applications. Here are common methods used to bond nonwoven fabrics in a nonwoven fabric production line:

Thermal Bonding:

Process: Thermal bonding involves using heat and pressure to melt and fuse the fibers together. In this process, the nonwoven fabric passes through heated rollers or plates, which apply pressure and heat to bond the fibers. The heat-sensitive fibers in the web melt and form bonds when pressed together.

Applications: Thermal bonding is widely used in the production of nonwoven fabrics for hygiene products, like diapers and sanitary napkins, as well as for some industrial applications.

Chemical Bonding:

Process: Chemical bonding relies on the application of chemical binders or adhesives to the nonwoven web. The binders act as adhesives that hold the fibers together when they dry. After application, the fabric may go through an oven or drying process to cure the binder.

Applications: Chemical bonding is used in applications such as medical textiles, geotextiles, and some filtration materials.

Needlepunching:

Process: Needlepunching is a mechanical method of bonding where the nonwoven fabric is passed through a bed of barbed needles. The needles mechanically entangle and interlace the fibers as they pass through the web. This process creates a strong and durable bond.

Applications: Needlepunched nonwovens are commonly used in automotive interiors, felt fabrics, carpets, and some industrial applications.

Hydroentanglement (Spunlacing):

Process: Hydroentanglement, also known as spunlacing, uses high-pressure water jets to entangle and bond the fibers in the nonwoven web. The water jets create mechanical entanglement, resulting in a fabric with good integrity.

Applications: Spunlaced nonwovens are used in medical wipes, industrial wipes, and cleaning cloths, among other applications.

Ultrasonic Bonding:

Process: Ultrasonic bonding involves the use of ultrasonic vibrations to create localized heating at the points where fibers should be bonded. The heat generated by the vibrations fuses the fibers together.

Applications: Ultrasonic bonding is often used in medical face mask production, disposable protective clothing, and some filtration media.

Adhesive Bonding:

Process: Adhesive bonding involves the application of adhesive substances to bond the fibers. These adhesives can be applied using different methods, such as spray, powder, or roll coating.

Applications: Adhesive bonding is used in various nonwoven applications, including automotive components and construction materials.

Calendering:

Process: Calendering involves passing the nonwoven fabric through heated rollers that compress the fabric. The heat and pressure applied during calendering create bonds between the fibers, resulting in a smoother and denser fabric.

Applications: Calendering is often used to enhance the surface smoothness and thickness uniformity of nonwoven fabrics used in printing and laminating applications.