Nonwoven Fabric Manufacturing Techniques

Nonwoven Fabric Manufacturing Techniques

Summary

suntech shares non-woven technology with you.Fabric is manufactured in three ways; weaving, knitting and nonwoven process. Among those processes nonwoven is comparatively latest process of fabric manufacturing.

Nonwoven Fabric Manufacturing Techniques

Due to the impact of the covid-19 epidemic in 2020, most industries have experienced a period of suspension of operations, and various economic activities have temporarily come to a standstill. In this situation, the non-woven fabric industry is busier than ever. As the demand for products such as disinfection wipes and masks has reached an unprecedented level, news reports about the surge in demand for substrate materials (ie meltblown materials) have become mainstream, and many people have heard a new word for the first time-non-woven fabrics , People began to pay more attention to the important role of non-woven materials in protecting public health. 2020 may be a lost year for other industries, but this situation does not apply to the non-woven industry.Click to share to LinkedIn


How to produce non-woven fabrics?

suntech shares non-woven technology with you.Fabric is manufactured in three ways; weaving, knitting and nonwoven process. Among those processes nonwoven is comparatively latest process of fabric manufacturing. Nonwoven fabrics are one type of textile fabrics or a manufactured sheet made of a fibrous layer, which may be a carded web, a fiber web, or any system of randomly laid or oriented fibers or threads, possibly combined with textile or non-textile materials such as conventional woven fabrics, plastic films, foam layers, metal foils, etc., & forming them with a mechanically bound or chemically bonded textile product.

 

Nonwoven Fabric Manufacturing Techniques

Nonwoven manufacturing techniques is basically a continuous process in which the web laying and web bonding are performed by two consecutive machines. In general, the nonwoven formation processes consists of two basic steps, web formation followed by bonding.

 

The web formation in nonwoven production is a critical contributor of the end-use product performance. There are three basic methods of web formation: dry laid; wet laid; and polymer laid. The latter one classified as spun laid and melt blown web formations which are particularly applicable for synthetic polymers. Click to share to Facebook

 

Web Formation Process


1.Dry Laid or Air Laid Nonwoven Process:

Dry laid or Air laid is the staple fiber based web laying process involves three major steps. They are fiber preparation (by opening and mixing processes), web formation (by carding or by air-lay processes) and finally web stacking (by parallellay, cross-lay, and perpendicular-lay processes). Flowchart of dry laid process is given below.try suntech Non-woven fabric

 

Flow Chart of Dry Laid Manufacturing Process:

Raw material

(Natural fibers, man-made fibers, inorganic fibers)

Preparation

(Opening to loose material, blending)

Web forming

1. Carding process (Parallel laid, cross laid)

2. Aerodynamic process (Random laid web)

Web bonding

(Mechanical bonding/thermal bonding/chemical bonding)

Processing

(Finishing, dyeing, printing, coating)

Product

(Fiber nonwoven)

 

Conventional staple fibers are used are raw material in the dry-laid process, which are usually 12 to 100 mm in length. Classical textile carding or air laying machines are used to separate and orient the staple fiber mechanically for formation of fiber web. The objective of carding is to separate the fiber stock into individual fibers with minimum fiber breakage and opening and blending of different species of fibers thoroughly. In a normal carding process, the fibers are more oriented along the machine direction than the cross direction. More random web structures can be obtained by cross lapping.

 

In the air laying process a lap or plied card webs are fed by a feed roller. The fibers are separated by a licker-in or spiked roller and introduced into an air stream. Finally, the fibers are collected on the condenser screen to form a web after desired fiber orientation. A conveyor is used for transporting the web from condenser to the bonding area. The length of fibers used in air laying is ranging from 20 to 60 mm. A higher production speeds can be achieved with shorter fiber as they are transported easily in the air stream with larger amount of fibers per unit volume of air and deposited on the condenser. Higher air volume is required for longer fibers to avoid entanglement. The limitations associated with this air laying are speed, web uniformity and weight. It is difficult to prepare isotropic webs lighter than 30 g/m2 by the air laid process.

 

However, voluminous, isotropic and uniform web can be successfully prepared from a wide variety of fibers such as natural, synthetic, glass, steel, carbon, etc., by this method. This will allow the production of webs from blends of cotton with other staple fibers. The air-laid webs usually have basis weights ranging from 30 to 2500 g/m2. Typical end uses for air-laid nonwoven fabrics are the fabrics for apparel and upholstery backings, carpet backing, interlinings for garments, linings, filter media, medical fabrics, diaper coverstock, wipes, insulation, geotextiles and personal hygiene products.

 

2.Wet Laid Process:

The wet laid manufacturing process of nonwoven fabric is essentially based upon the paper making process. The wet laid process is suitable for fibers which can be dispersed in fluids. Like in the paper making process, very short fibers dispersed in water are laid on a traversing perforated lattice. Flowchart of wet laid process is given below.


Flow Chart of Wet Laid Manufacturing Process:

Raw material

(Short fibers, cellulose)

Preparation

(Blending, manufacturing of fiber-water suspension)

Web forming

(Spreading of suspension into a screen belt)

Web bonding

(mechanical bonding/thermal bonding/chemical bonding)

Processing

(Finishing, dyeing, printing, coating)

Product

(Fiber nonwoven)

 

In wet-laid nonwoven manufacturing process the fibers are mixed with chemicals and then suspended in water to make the slurry. Then, specialized paper machines are used to drain the water off the fibers to form a uniform sheet of material like web, which is then bonded and dried.

 

Fibers shorter than 10 mm are suitable for wet-laid nonwoven process and the resulting fabric has a basis weight ranging from 10 to 540 g/m2. The wet laid nonwoven process has merits of high productivity, high uniformity at low basis weight and control of fiber orientation of properties, as compared to air laid process. Typical applications for wet-laid nonwovens include wipes, surgical gowns, drapes, towels, tea bags, etc.

 

Web Bonding Techniques

The web bonding techniques are generally classified into three categories, mechanical, chemical, and thermal bonding, based on raw material fibers, end-use applications and web formation technology. Often, a combination of different bonding methods is used to achieve products with certain properties. Mechanical bonding can be further classified as needle punching, stitch bonding, and spunlacing (or hydroentangling). In the needle punching process, fiber web is bonded by mechanically interlocking the fibers by punching with barbed needles. As the unbonded web moves through the needle loom, the web is consolidated and becomes stronger because of the fiber interlocking. The level of consolidation is controlled by the needle punching density and depth of needle penetration.

 

It is the only bonding method suitable for heavyweight nonwoven fabrics. The needlepunched fabrics are extensible, bulky, conformable, distortable and extremely absorbent. Both dry laid and polymer laid webs can be needle punched. Stitch bonding is the process of bonding a web by stitching with yarns, filaments, or fibers. Spunlacing is a process of entangling individual fibers with each other using high-pressure water jets, which cause the fibers to migrate and entangle. The water jets create turbulence inside the web which causes enough interlocking between fibers to produce strong fabrics. Spunlace fabrics have more appealing properties than the needle punched fabrics. The typical applications of spunlace fabrics are wipes, medical gowns, dust cloths, garment and leather interlining etc. Faster rate of production can be achieved with spunlacing process than that of needlepunching as there is no reciprocating mechanical part. Other methods of bonding such as chemical bonding and thermal bonding are generally used for synthetic fibers.

 

Non-woven fabric process


Equipment process:

Suction machine screw filter metering pump box stretcher net forming machine hot rolling machine winder slitting machine.

 

Product process flow:

Raw material (ingredients)heatingextrusionfilteringbox bodystretchingnet-forming hot rollingcoiling and cuttingweighinginspectionpackingwarehousing.

 

1 Filling formula workshop accessories polypropylene finished product.

2 production workshop

Accept the production plan organize production process control supervision and inspection confirm warehousing.

3 Assembly workshop

Folding nailing tag tethering card semicolon bagging boxing sealing packing.

 

With 50 years of technical precipitation and design experience, suntech has developed and produced spunmelt nonwoven machines, spunbonded nonwoven machines, meltblown machines and other nonwoven machines and nonwoven materials to help cotton soft towels, wet wipes, and protection and hygiene. The development of supplies and other industries and human health and hygiene services provide convenience for human life.


Suntech ST-AMB Meltblown machine