Offline Composite Processing Technology for Spunbond Nonwoven Fabric

Offline composite processing technology is one of the most commonly used production technologies to increase product added value. It is characterized by flexibility, convenience, and wide adaptability. Composite processing of different materials and different processes can produce many new materials with excellent performance. This article introduces several offline composite methods often used for spunbond nonwoven fabric, including thermal calendering, ultrasonic bonding, and film coating, providing reference and guidance for spunbond nonwoven fabric manufacturing enterprises to enhance product differentiation and improve their competitive edge.

Thermal Calendering of Spunbond Nonwoven Fabric

Thermal calendering is a commonly used composite process that bonds multiple layers of material together through a calendering machine. This process is characterized by high production speed, mature and reliable technology, and relatively simple operation and management. The resulting products have high strength and good barrier properties. To ensure bonding strength, the melting points of each layer of material should not differ significantly, and the total weight of the product should ideally be below 150g/m². The downside of this process is that the resulting spunbond nonwoven fabric has a less desirable texture and reduced air permeability.

Ultrasonic Bonding of Spunbond Nonwoven Fabric

Ultrasonic bonding is a process that uses ultrasonic waves to bond multiple layers of material. When using ultrasonic bonding, the melting points of each layer of material are not strictly required, making it suitable for materials with significant melting point differences. The process is relatively simple to operate and manage.

Ultrasonic bonding offers high production speeds, and the resulting products have high strength and good barrier properties. By changing the shape of the mold, beautiful patterns can be formed on the spunbond nonwoven fabric, which also facilitates product recycling. However, the strength of ultrasonic bonding is not as high as that of thermal calendering, and the surface cleanliness of each layer of material is crucial.

Film Coating of Spunbond Nonwoven Fabric

Film coating is an important method for bonding multiple layers of spunbond nonwoven fabric to produce products with high barrier properties. In actual production, there are various composite methods such as "one fabric, one film," "two fabrics, one film," and "three fabrics, two films." Film coating technology is also relatively mature, with strong controllability of film thickness, high production speed (approximately 100m/min), simple operation and management, and high product strength and barrier properties.

When using film coating, the film material is generally low-melting-point PE, while the commonly used PP and PET nonwoven materials have higher melting points. The temperature of the PE melt does not damage other materials. Therefore, the melting points of each layer of material are not strictly required, but the uniformity of the base material is crucial. There should be no holes or severe mesh defects to avoid "leakage" during processing. Under normal circumstances, the weight of the base material for film coating should be ≥18g/m².

Hot Melt Adhesive Bonding of Spunbond Nonwoven Fabric

Hot melt adhesive bonding uses the fluidity of hot melt adhesive to penetrate the surface of the materials to be bonded. After cooling, the adhesive solidifies or reacts to form a bond. Hot melt adhesive bonding is a non-contact composite process that has low requirements for the minimum weight, uniformity, and unwinding tension of the base material. Since the amount of adhesive sprayed is small, the impact on the base material's air permeability is minimal, and the temperature tolerance requirements are low.

The main features of hot melt adhesive bonding are fast bonding speed, solvent-free, and simple production process.

A hot melt adhesive bonding production line mainly consists of unwinding devices (2 sets), spray adhesive equipment (2 sets), a composite device, and a slitting and winding device, with a small installed capacity. Compared with coating methods, hot melt adhesive spraying has advantages such as high production speed, high efficiency, low adhesive usage, easy adjustment, low cost, small equipment footprint, and a short investment payback period.

Products made from this type of spunbond nonwoven fabric have the advantages of soft texture, strong shielding, high barrier capability, and good air permeability. They are breathable but not liquid-permeable, and their tensile strength is greater than that of traditional composite processes.

Offline composite processing technology for spunbond nonwoven fabric has become an important means for international well-known multinational companies to enhance their market competitiveness. Enterprises can flexibly choose different technologies and equipment according to their spunbond nonwoven fabric production lines and market characteristics to improve their competitive edge and achieve the best economic benefits. If you need PE film coating nonwoven and PE film glue lamination nonwoven for baby diaper, contact us.