Non-woven, origin, properties, and application
Nonwovens do not depend on the interlacing of yarn for internal cohesion. Intrinsically they have neither an organized geometrical structure. They are essentially the result of the relationship between one single fiber and another. This provides nonwoven fabrics with characteristics of their own, with new or better properties (absorption, filtration) and therefore opens them up to other applications.
- 1 History of Nonwovens
- 2 Applications of Non-Woven Fabrics
- 3 Felted Fabrics
- 4 Bonded Fabrics
- 5 Laminated Fabrics
- 6 Features of Nonwovens
- 7 Properties of Nonwovens include
Nonwovens are defined by ISO standard 9092 and CEN EN 29092. “A nonwoven is a sheet of fibres, continuous filaments, or chopped yarns of any nature or origin, that have been formed into a web by any means, and bonded together by any means, with the exception of weaving or knitting.
Felts obtained by wet milling is not nonwoven. Wet laid webs are nonwovens provided they contain a minimum of 50% of man-made fibres or other fibres of non-vegetable origin with a length to diameter ratio equals or superior to 300, or a minimum of 30% of man-made fibres with a length to diameter ratio equals or superior to 600, and a maximum apparent density of 0.40 g/cm³.
Composite structures are considered nonwovens provided their mass is constituted of at least 50% of nonwoven as per the above definitions, or if the nonwoven component plays a prevalent role.”
History of Nonwovens
The origins of nonwovens are not glamorous. In fact, they resulted from recycling fibrous waste or second quality fibres left over from industrial processes like weaving or leather processing. They also resulted from raw materials restrictions e.g. during and after the Second World War or later in the communist-dominated countries in Central Europe. This humble and cost dominated origin of course lead to some technical and marketing mistakes; it is also largely responsible for two still lingering misconceptions about nonwovens: they are assumed to be (cheap) substitutes; many also associate them with disposable products and for that reason did consider nonwovens as cheap, low quality, items.
Not all nonwovens end in disposable applications. A large part of the production is for durable end-uses, like in interlinings, roofing, geotextile, automotive or floor covering applications, etc. However, many nonwovens especially light-weight ones are indeed used as disposable products or incorporated into disposable items. In our view, this is the ultimate sign of efficiency. Disposability is only possible for cost-efficient products that concentrate on the essential required characteristics and performances and provide them without unnecessary frills.
Most nonwovens, disposables or not, are high-tech, functional items, e.g. with ultra-high absorbency or retention for wipes, or with softness, strike-through and no wetback properties for those used into hygiene articles, with outstanding barrier characteristics for medical applications in the operation room, or better filtration possibilities because of their pores dimension and distribution, etc. They weren’t manufactured with the aim of disposability but in order to fulfil other requirements. They mainly became disposable because of the sectors they are used in (hygiene, healthcare) and of their cost-efficiency. And disposability very often creates an additional benefit to the users. As disposable items have never been used before, there is then a guarantee that they do possess all the properties required as opposed to reused laundered fabrics.
In the 19th century, (when England was the leading textile-producing country), realizing that large amounts of fibre were wasted as trim, a textile engineer named Garnett developed a special carding device to shred this waste material back to fibrous form. This fibre was used as a filling material for pillows.
The Garnett Machine, though greatly modified, today still retains its name and is a major component in the non-woven industry. Later on, manufacturers in Northern England began binding these fibers mechanically (using needles) and chemically (using glue) into batts. These were the precursors of today’s non-wovens. This art remained the same into the middle of the 20th century and patents as late as the 1930s depict such batts specially made to insulate railroad boxcars in the U.S.Now in the 21st century, though some fillings and paddings are still made as they were in England almost 2 centuries ago, non-wovens have progressed beyond Garnett’s dreams.
Non-woven fabric was used between the Space Shuttle Discovery’s heat-resistant tiles and the spaceship’s skin and non-wovens were part of the spacesuits worn to the moon. The limits to the use of non-wovens remain only in the imagination of man, and new innovations are developed on a steady basis.
- 1936 Dr Carl Nottebohm starts the development of Nonwovens in Weinheim
- 1948 Start of dry-laid staple fibre Nonwovens production, the introduction of Vliesline garment interlinings and Video window cloth.
- 1950 Joint Venture to produce dry-laid Nonwovens in USA (Pellon)
- 1960 Joint Venture to produce dry-laid Nonwovens in Japan (Japan Vilene Company)
- 1965 Introduction of spun-bonded polyamide Nonwovens technology developed by Dr Ludwig Hartmann.
- 1973 Production start of wet-laid Nonwovens. Production start of polyester spun bond at new Kaiserslautern plant.
- 1982 Production start of lightweight Polypropylene Nonwovens.
- 1984 Start-up of the first non-European facility to produce polyester spun-bonded Nonwovens in North Carolina (USA)
- 1985 Acquisition of a leading producer of staple fibre Nonwovens in Brazil
- 1988 Opening of a new research and development centre for staple fibre Nonwovens incorporation hydro entanglement technology in Weinheim
- 1994 Joint Venture with our Japanese partner Japan Vilene Company to produce interlinings in Suzhou/China.
- 1997 Merging of the Staple-Fibre and Spun bonded Nonwovens Business Groups. Formation of 6 divisions with global responsibilities.
- 1998 The Italian company Marelli & Berta, a manufacturer of woven interlinings joins the Freudenberg Group.
- 1999 Evolon, a new technological breakthrough. The first continuous microfibre spunlaced fabric with a large number of applications.
- 2002 New Plant Concept: a 50 million investment to modernize and restructure the facilities in Europe and North America
- 2006 Freudenberg Nonwovens acquires Scimat Ltd, Swindon/UK – the leading finisher of battery separators
- 2007 Restructuring of the North American industrial business to simplify product ranges and improve supply chain efficiency. Commissioning of a new spunbond line at Fiberweb’s site atNorrköping, Sweden
- 2008 Creation of two global hygiene business units – Consumer Fabrics and Airlaid, and three regional industrial businesses – Americas Industrial, Europe Industrial and Terram. Acquisition of a Chinese polyester nonwoven fabric producer – Hengguan
- 2009 Commissioning of a new, leading spunbond line at Fiberweb’s site at Trezzano Rosa, Italy. Formation of a 50/50 JV between Petropar (Brazil) and Fiberweb, comprising Fitesa Brazil and Fiberweb spunbond sites at Washougal, USA and Queretaro, Mexico to form FitesaFiberweb, the second-largest spun-bond producer in the Americas
Applications of Non-Woven Fabrics
Personal care and hygiene
baby diapers, feminine hygiene products, adult incontinence items, dry and wet pads, but also nursing pads or nasal strips, bandages and wound dressings
like operation drapes, gowns, and packs, face masks, dressings and swabs, osteomy bag liners, isolation gowns, surgical gowns, surgical drapes and covers, surgical scrub suits, caps
interlinings, insulation and protection clothing, industrial workwear, chemical defence suits, shoe components, etc.
wipes and dusters, tea and coffee bags, fabric softeners, food wraps, filters, bed and table linen, etc.
boot liners, shelf trim, oil and cabin air filters, moulded bonnet liners, heat shields, airbags, tapes, decorative fabrics, etc.
roofing and tile underlay, thermal and noise insulation, house wrap, understanding, drainage, etc.
asphalt overlay, soil stabilization, drainage, sedimentation and erosion control, etc.
Hevac, Hepa, Ulpa filters, gasoline, oil, and air – including HEPA filtration, water, coffee, tea bags, liquid cartridge and bag filters, vacuum bags, allergen membranes or laminates with non-woven layers
cable insulation, abrasives, reinforced plastics, battery separators, satellite dishes, artificial leather, air conditioning, coating.
Agriculture, home furnishing, leisure and travel, school and office
soil stabilizers and roadway underlayment, foundation stabilizers, erosion control, canals construction, drainage systems, geomembranes protection, frost protection, agriculture mulch, pond and canal water barriers, sand infiltration barrier for drainage tile
Wool felt is the most common non-woven fabric and is produced by using short-staple fibres from wool or other animal hairs (such as camel). Wool is an ideal fibre because its surface has natural hooks like scales, which when moisture, heat and vigorous movement are applied, interlock with each other. The heat and damp conditions cause the fibres to curl up, and the scales locking together prevents the fibres from straightening out again. When you wash a natural wool jumper and it shrinks in size the jumper is actually felting and you can’t make it bigger again no matter how hard you try to stretch it back.
There are three main methods of making bonded fabrics:
- Dry laid: a web of fibres is laid in a drum and hot air is injected to bond the fibres together.
- Wet-laid: a web of fibres is mixed with a solvent that softens the fibres and releases a glue-like substance that bonds the fibres together and then the web is laid out to dry.
- Direct spun: the fibres are spun onto a conveyer belt and glues are sprayed onto the fibres, which are then pressed to bond; if the fibres are thermoplastic (will change shape with heat) then the glue is not needed in this process.
Felted and bonded fabrics applications
Hats, jackets, toys, and snooker table covers are some commonly used for wool felts.
Bonded fabrics are used for disposable products such as clothes, medical masks, and table linen. They are also used for interfacings for stiffening and strengthening clothing and dressmaking (e.g. Vilene).
Laminated fabrics are made by bonding two or more fabrics together. Many fabrics require extra insulation or protection, and the foam is bonded to provide this. Sometimes comfort can be an issue with PVC fabrics, so a softer fabric may be bonded instead of using a lining. Making a fabric breathable and waterproof may require lamination of a membrane, as in Gortex and Sympatex.
Nonwoven fabrics are products made of parallel laid, cross-laid or randomly laid webs bonded with the application of adhesive or thermoplastic fibers under application of heat and pressure.
Features of Nonwovens
The versatility of nonwovens means that they can provide innovative, cost-effective, and sometimes unexpected answers to innumerable business challenges. Innovative products and solutions can be created; problems can be solved and needs to be met by incorporating appropriate properties. These properties are often combined to create fabrics suited for specific jobs while achieving a good balance between product use-life and cost. Specific properties can be achieved by selecting raw materials and methods or by applying finishing treatments to nonwovens, such as printing, embossing, molding, laminating, etc.
Properties of Nonwovens include
- Abrasion resistant
- Colour fast
- Crease resistant
- Dry cleanable
- Dust free
- Flame resistant
- Heat sealable
- Kind to skin
- Lint free
- Liquid repellent
- Protective (bacterial barrier)
- Rot and mildew resistant
- Tear resistant