Nonwoven Fabrics Explained: Web Formation , Web laying, Bonding Techniques & Fibre Suitability Guide
Nonwovens are quietly changing important industries such as healthcare and automotives. Nonwovens are different from woven and knitted textiles because fibres in nonwovens are bonded together mechanically, thermally or chemically, without having to weave or knit. However, don’t think that the simplicity of the process means it’s easy. They are used in many areas such as with surgical masks, geotextiles, baby diapers, filters, car interiors and high-tech fashion.
It presents all the key info on nonwovens, for example describing the ways they’re made, preferred fibres for each type of nonwoven and the reasons behind choosing a specific method for end applications. Textile students, researchers and professionals should use this book as their complete and useful guide.
What Are Nonwoven Fabrics?
Nonwoven fabrics are produced by entangling or bonding fibres straight into a fabric form, without using weaving or knitting. Some of these fabrics can be tossed away, others are made to last and their features vary from flexible and easy to harsher ones based on how they are made and who uses them.
Types of Webs in Nonwoven Fabrics & Fibre Laying Techniques
In the context of nonwoven fabrics, the very first step in the manufacturing process is web formation. This stage determines the structure, strength, uniformity, and overall performance of the final fabric. The term "web" here simply refers to a loose sheet or network of fibres that haven’t yet been bonded.
But not all webs are created the same. Based on the type of fibre and web formation technique, nonwovens are classified into different categories. Let's explore this step in detail.
1. Staple Fibre-Based Webs
These webs are made using staple fibres—which are short-length fibres (usually 1.5 to 15 cm). The fibre is first opened, cleaned, and then laid into a web using one of two main processes:
a) Dry-Laid Webs
This is one of the most common methods for nonwoven production using staple fibres. The fibres are opened and passed through a carding machine, which forms a thin batt or web. Based on how this carded web is arranged, there are three main fibre laying types:
Parallel-Laid Webs:
In this method, fibres lie mostly in the machine direction (the direction in which the web moves during processing).
Advantages: Good tensile strength in one direction
Used For: Lightweight cleaning wipes, absorbent layers in hygiene products
Cross-Laid Webs:
Multiple layers of carded web are laid at angles using cross-lappers, usually forming an ‘X’ orientation.
Advantages: Improved strength in both directions (machine and cross direction)
Used For: Upholstery, automotive insulation, mattress padding
Random-Laid Webs (Air-Laid):
Here, fibres are distributed using air turbulence so they settle randomly on the conveyor.
Advantages: Balanced strength in all directions, highly uniform
Used For: High-end wipes, filter media, cosmetic pads
b) Wet-Laid Webs
Similar to the paper-making process. Fibres are suspended in water, then deposited on a mesh to form a web as water drains.
Fibres Used: Mostly rayon, polyester, glass (with very short fibre length under 10 mm)
Used For: Medical drapes, tea bags, wallcoverings
2. Continuous Filament-Based Webs
Instead of using short staple fibres, this method involves extruding long, continuous filaments from polymers. These filaments are laid down directly to form webs.
a) Spun-Laid Webs
Polypropylene or polyester thermoplastic polymers are melted and stretched through small nozzles which is why they are also called spunbonded webs. The filaments are pulled out and laid on a moving belt to produce a web.
Strengths: High uniformity, good bonding potential, excellent mechanical properties
Used For: Packaging, shopping bags, disposable medical gowns, geotextiles
b) Melt-Blown Webs
In this method, a high-velocity hot air stream blows the molten polymer into ultrafine microfibres, which are directly laid to form the web.
Strengths: Extremely fine fibres with high surface area
Used For: N95 filters, surgical masks, insulation, oil-absorbent mats
Web Laying Techniques in Nonwovens
Laying techniques refer to how fibres are oriented during web formation. This plays a major role in the final fabric’s direction-wise strength, flexibility, appearance, and performance.
Let’s break down the three major laying types:
1. Parallel-Laying
Process: The carded fibres are deposited in a straight line along the machine direction.
Properties: High tensile strength in the lengthwise direction but relatively weak across the width.
Common Uses: Lightweight nonwovens like tissue backings, certain hygiene layers, inner linings in garments.
2. Cross-Laying
Process: After carding, layers of web are laid crosswise (usually ±45° or ±90°) using a cross-lapper. This improves the dimensional stability of the fabric.
Properties: Balanced mechanical strength both lengthwise and widthwise. Helps avoid tearing and stretching during use.
Common Uses: Furniture padding, automotive applications, sound insulation, heavy-duty filters.
3. Random-Laying (Air-Laid)
Process: Uses air streams to deposit the fibres in all directions, giving a uniform random orientation.
Properties: Isotropic strength (same in all directions), extremely soft and uniform texture.
Common Uses: High-performance wipes, napkins, dusting cloths, cosmetic pads, premium filtration media.
Web Bonding Techniques in Nonwovens: How Loose Fibre Becomes Fabric
Forming the web is just the first half of the nonwoven story. The second and equally important part is bonding. This is where the web of loose fibres is transformed into a coherent, stable fabric structure.
Bonding defines how the fibres are held together. It affects everything from fabric softness, strength, and breathability, to how it reacts under stress or after washing. There are three major types of web bonding techniques: mechanical, thermal, and chemical. Each has its own mechanism, compatible fibres, and suitable applications.
Let’s break them down one by one in simple terms.
1. Mechanical Bonding
In mechanical bonding, the fibres are physically entangled or stitched together—no heat or adhesives are required.
a) Needle Punching
This is like giving the fibre web thousands of tiny punches using barbed needles. These needles move up and down rapidly, pulling fibres through the web and locking them together through entanglement.
Fibre Types: Medium to long staple fibres like polyester, acrylic, and wool.
Fabric Feel: Thick, strong, and often rough to the touch.
Applications: Geotextiles, shoe linings, automotive carpet backings, blankets.
b) Hydroentanglement (Spunlace)
Here, high-pressure water jets shoot through the web, making the fibres twist and curl around each other. It’s gentler than needle punching and can work with delicate fibres.
Fibre Types: Rayon, polyester, cotton, blends.
Fabric Feel: Soft, cloth-like, and drapable.
Applications: Baby wipes, surgical gowns, cosmetic pads, facial tissues.
c) Stitch Bonding
Uses warp-knitting machines to add yarn stitches through the web. The stitching holds the fibres together without compressing them.
Fibre Types: Mostly used with thermoplastics and polyester.
Applications: Mattress covers, automotive linings, insulation, wall coverings.
2. Thermal Bonding
In thermal bonding, heat is applied to melt and fuse certain fibres in the web. Often, a bicomponent fibre (two materials in one fibre) is used—one part melts and bonds, the other stays solid for strength.
a) Hot Calendaring
The web is passed through heated rollers, which apply pressure and melt specific points in the fabric. The roller can be smooth or patterned.
Types:
- Area bonding: Full surface contact
- Point bonding: Dots or shapes across fabric for breathability
- Embossed bonding: Decorative patterns
Fibre Types: Polypropylene, polyester, bicomponent fibres like PE/PET.
Applications: Diapers, sanitary napkins, surgical masks, disposable garments.
b) Through-Air Bonding
Instead of pressure, hot air is passed through the web. The bonding fibres melt gently and evenly, making the fabric more lofty and soft.
Fibre Types: Bicomponent fibres (core-sheath types like PET/PE).
Applications: Air filters, soft quilt batting, premium hygiene products.
c) Ultrasonic Bonding
Uses high-frequency vibrations to generate heat at specific points, bonding thermoplastic fibres instantly. It’s fast and doesn’t require drying.
Fibre Types: Polypropylene, polyester.
Applications: Medical gowns, activewear seams, filter pockets.
3. Chemical or Adhesive Bonding
Here, chemical binders or adhesives are used to glue the fibres together. This method is flexible in terms of fibre types and web structures.
a) Saturation Bonding
The entire web is soaked in a chemical binder (like acrylic latex), then dried and cured.
Effect: Very stiff, hard fabric.
Applications: Wall coverings, industrial filters, disposable tablecloths.
b) Spray Bonding
Adhesive is sprayed over the surface of the web. This method is used when only partial bonding is desired—softer feel is preserved.
Applications: Quilt paddings, pillows, furniture padding.
c) Foam Bonding
The binder is applied as a foam instead of a liquid. Foam spreads evenly and allows precise control.
Advantage: Better chemical efficiency and reduced drying time.
d) Powder Bonding
Thermoplastic powder is sprinkled on the web and melted in an oven to bond fibres together.
Used For: Automotive interiors, stiff interlinings, decorative panels.
Choosing the Right Bonding Method
Every bonding technique has a unique impact on the nonwoven’s texture, strength, breathability, and even cost. Here's a simplified idea:
- Want softness? Go for hydroentanglement or through-air bonding.
- Need stiffness? Choose saturation or powder bonding.
- Need cost-efficiency? Use hot calendaring or spray bonding.
- Heavy-duty application? Needle punching is your go-to method.
The selection also depends on fibre compatibility, end-use durability, and whether the product is disposable or reusable.
Common Fibres Used in Nonwoven Production
1. Polypropylene (PP)
- Why It’s Used: Extremely lightweight, low cost, excellent thermoplastic properties.
- Bonding Compatibility: Perfect for thermal bonding.
- End Uses: Surgical masks, hygiene products, disposable gowns, shopping bags.
- Bonus: Hydrophobic by nature—repels moisture.
2. Polyester (PET)
- Why It’s Used: Strong, durable, resistant to stretching and shrinking.
- Bonding Compatibility: Works with all bonding methods, especially needle punching.
- End Uses: Automotive interiors, filters, insulation mats, clothing backings.
- Bonus: High dimensional stability and good UV resistance.
3. Rayon / Viscose
- Why It’s Used: Highly absorbent, soft, comfortable on skin.
- Bonding Compatibility: Great for hydroentanglement (spunlace) and chemical bonding.
- End Uses: Baby wipes, sanitary napkins, cosmetic pads, surgical wipes.
- Bonus: Made from wood pulp—biodegradable and breathable.
4. Cotton
Why It’s Used: Natural, breathable, biodegradable.
Bonding Compatibility: Works well with hydroentanglement and chemical bonding.
End Uses: Medical dressings, gauze, premium wipes, sanitary textiles.
Bonus: Skin-friendly and hypoallergenic, but more expensive.
5. Wool
Why It’s Used: Insulating, soft, flame-resistant by nature.
Bonding Compatibility: Suitable for needle punching.
End Uses: Blankets, acoustic panels, high-end insulation.
Bonus: Sustainable and biodegradable.
6. Acrylic
Why It’s Used: Soft, bulky, warm, and colourfast.
Bonding Compatibility: Mostly used with needle punching and chemical bonding.
End Uses: Furniture padding, soundproofing, insulation felts.
7. Glass Fibres
Why It’s Used: High heat resistance and tensile strength.
Bonding Compatibility: Chemical bonding or resin reinforcement.
End Uses: High-efficiency filters, roofing membranes, composite reinforcements.
Bonus: Non-flammable, but brittle and not skin-friendly.
8. Bicomponent Fibres (e.g., PET/PE, PP/Co-PET)
Why It’s Used: Designed specifically for thermal bonding, where the outer sheath melts and the core stays intact.
Bonding Compatibility: Thermal bonding (hot calendaring, through-air).
End Uses: Baby diapers, quilt battings, medical textiles, air filters.
Speciality and Emerging Fibres in Nonwovens
- Over the past several years, people have become more interested in eco-friendly and performance fibres.
- Using starch made from corn, Polylactic Acid (PLA) is a bio-based biodegradable plastic important for farming and cleaning.
- Bamboo products are by nature both anti-bacterial and biodegradable.
- Eco-friendly packaging materials and automotive insulation may use banana and coconut fibres.
- Polyethylene terephthalate (PET): More often used in long-lasting nonwovens and geotextiles.
Real-World Scenario: Why Fibre Matters
Let’s say a manufacturer is producing surgical wipes. They need the fabric to be absorbent, soft, and skin-friendly. A blend of viscose and polyester would be ideal, bonded through hydroentanglement for softness and strength.
But if the same company is producing industrial insulation mats, they’d use needle-punched polyester or even wool blends for higher loft and acoustic properties.
Every end-use has a fibre that fits just right technically and economically.
Matching Bonding Techniques with Suitable Fibres
- Each bonding technique has fibre compatibility:
- Needle Punching: Wool, polyester, acrylic (medium to long staple)
- Hydroentanglement: Rayon, cotton, polyester (short staple, fine denier)
- Thermal Bonding: Bicomponent fibres like PE/PP, PET/Co-PET
- Chemical Bonding: Rayon, polyester (requires good surface adhesion)
Conclusion: Why Every Textile Student & Professional Should Master Nonwovens
Nonwoven production is affordable, can be managed in large volumes and works for a variety of uses. Explore the differences in webs, bonding strategies, fiber types and design recommendations and you will build expertise needed to do well in medical products development.
It’s not just a subject it’s a future-ready skill. So start diving deeper into nonwoven technology and keep innovating.
🔗 Related Posts to Include:
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2. Lyocell Fibre Explained: The Eco-Friendly Textile Revolution You Shouldn’t Miss
-Discover how Lyocell fibre plays a role in sustainable textile innovation, including its use in nonwovens.
3. Microplastic Pollution from Synthetic Fabrics: Urgent Projects & Solutions for Students
-Relates to environmental impact of synthetic nonwoven fibres and innovative solutions.