What is non woven fabric? Nonwoven fabric is a fabric-like material made from staple fiber (short) and long fibers (continuous long), bonded together by chemical, mechanical, heat or solvent treatment. The term is used in the textile manufacturing industry to denote fabrics, such as felt, which are neither woven nor knitted. Some nonwoven materials lack sufficient strength unless densified or reinforced by a backing. In recent years, nonwovens have become an alternative to polyurethane foam.
Raw Materials
Polyester is the most frequently used fibres in the United States; olefin and nylon are used for their strength, and cotton and rayon are used for absorbency. Some acrylic, acetate, and vinyon are also being used.
Fibres are selected on the basis of their properties and expected performance in end uses. New, first quality fibres are preferred over reused or reprocessed fibres. Both staple and filament fibres are used, and it is possible to blend fibres of different lengths as well as fibres of different generic groups. The selection of fibres depends on the product proposed, the care typically given it, and the expected or desired durability. As in the manufacture of all fabrics, the cost of the fibres used is important, as it in turn influences the cost of the final product.
Characteristics Of non woven fabric rolls
- The particular set of properties that a non-woven fabric may have is dependent upon the combination of factors in its production. The range of characteristics is wide.
- The appearance of non-woven fabrics may be paper like, felt like, or similar to that of woven fabrics.
- They may have a soft, resilient hand, or they may be hard, stiff, or broadly with little pliability.
- They may be as thin as thin as tissue paper or many times thicker.
- They also may be translucent or opaque.
- Their porosity may range from low tear and burst strength to very high tensile strength.
- They may be fabricated by gluing, heat bonding, or sewing.
- The drapability of this type of fabrics varies from good to none at all.
- Some fabrics have excellent launderability; others have none. Some may be dry-cleaned.
types of non woven fabrics
here are four main types of non-woven products: Spunbound/Spunlace, Airlaid, Drylaid and Wetlaid. This article covers these main types in detail.
The four main and most common types of-non-woven products are:
- Spunbound/Spunlace.
- Airlaid.
- Drylaid.
- Wetlaid
Spunbound/Spunlace
Spunbound fabrics are produced by depositing extruded, spun filaments onto a collection belt in a uniform random manner followed by bonding the fibres. The fibres are separated during the web laying process by air jets or electrostatic charges. The collecting service is usually perforated to prevent the air stream from deflecting and carrying the fibres in an uncontrolled manner. Bonding imparts strength and integrity to the web by applying heated rolls or hot needles to partially melt the polymer and fuse the fibres together. Since molecular orientation increases the melting point, fibres that are not highly drawn can be used as thermal binding fibres. Polyethelene or random ethylene-propylene copolymers are used as low melting bonding sites.
Spunbound products are employed in carpet backing, geotextiles, and disposable medical/hygiene products, automotive products, civil engineering and packaging products.
The process of Spunbound non-woven production tends to be more economical as the fabric production is combined with the fibre production.
Airlaid
The process of airlaying is a non-woven web forming process that disperses into a fast moving stream and condenses them onto a moving screen by means of pressure or vacuum.
Airlaid fabrics is mainly composed of woodpulp and has a nature of absorbing well. It can be mixed with a definite proportion of SAP to improve its capabilities of absorbing wet. Airlaid non-woven is also referred to as dry paper non-woven. The nonwoven is made through the airlaying process. Transit the woodpulp into the bundle of airflow to make the fibres disperse and agglomeration on the floating web. Airlaid non-woven is reinforced of web.
Airlaid non-woven products are employed in a number of different products across a wide range of industry’s including; the interlining of clothes, medical and hygiene products, embroidery material and filter material.
Drylaid
Dry laid webs are mainly produced using staple fibres natural or manmade. Dry laid webs formation mainly consists of 4 steps:
Staple fibre preparation --> Opening, cleaning, mixing & blending --> Carding --> Web laying.
Advantages of Drylaid non-woven production include; The isotropic structure of the web, voluminous webs can be produced and a wide variety of process able fibres such as natural, synthetic, glass, steel and carbon.
Drylaid non-woven products are employed by many products ranging from cosmetic wipes and baby diapers to beverage filtration products.
Wetlaid
Wetlaid non-woven are non-wovens made by a modified papermaking process. That is, the fibres to be used are suspended in water. A major objective of wet laid nonwoven manufacturing is to produce structures with textile-fabric characteristics, primarily flexibility and strength, at speeds approaching those associate with papermaking.
Specialized paper machines are used to separate the water from the fibres to form a uniform sheet of material, which is then bonded and dried. In the roll good industry 5 -10% of nonwovens are made by using the wet laid technology.
Wetlaid is used for a wide ranging amount of industries and products. Some of the most common products that use wetlaying non-woven technology include; Tea bag paper, Face cloths, Shingling and Synthetic fibre paper.
Some other common types of non-wovens include: Composite, Meltblown, Carded/Carding, Needle punch, Thermal bonded, Chemical bonded and Nanotechnology.
Applications of Non-Woven Fabrics
Since these are chemically less reactive, and less hazardous for the environment, they are opted by 'n' number of different industries.
1、Agriculture
These non-woven fabrics are largely used to get rid of the weeds, protect the top layer of the soil during the soil erosion, and to keep your garden clean and free of dust. When there is soil erosion, the non woven geotextile, will act like a filter, which will not allow the soil to pass by, and thus prevent your garden or farm from losing its fertility layer. Geotextile fabrics also offer frost protection to the young seedlings, and to the plants that cannot survive cold conditions.
· Insect damage protection: crop covers
· Thermal protection: seed blankets
· Weed control: impermeable barrier fabrics
. Crop protective fabric, nursery cloth, irrigation cloth, insulation curtains and so on.
. Agriculture : plant cover;
2、Industry
In many industries, non-woven geotextile is used as insulation materials, covering materials, and as filters. Due to their excellent tensile strength, they work simply great in the industries.
2-1、 Industrial non-woven fabrics
reinforcing materials, polishing materials, filter materials, insulation materials, cement bags, geotextiles, covering cloth and so on.
2-2、Automotive and Transport
Interior Trim: boot liners, parcel shelves, headliners, seat covers, floorcovering, backings and mats, foam replacements.
Insulation: exhaust & engine heat shields, moulded bonnet liners, silencer pads.
Vehicle performance: oil and air filters, fibre reinforced plastics (body panels), aircraft brakes.
3、Building industry
Products in this sector are often durable and high bulk fabric. Uses include;
· Insulation and moisture management: roofing and tile underlay, thermal and sound insulation
· Structural: Foundations and ground stabilisation
4、Household Domestic uses
Produces in this sector are often used as filters and are disposable including;
- Wipes/mops
- Vacuum cleaner bags
- Washcloths
- Kitchen and fan filters
- Tea and coffee bags
- Coffee filters
- Napkins and tablecloths
Furniture construction: Insulators to arms and backs, cushion ticking, linings, stitch reinforcements, edge trim materials, upholstery.
Bedding construction: Quilt backing, mattress pad components, mattress covers.
Furnishings: window curtains, wall and floorcoverings, carpet backings, lampshades
5、clothing use non-woven fabrics
lining, adhesive lining, flakes, stereotypes cotton, all kinds of synthetic leather fabric and so on.
· Personal Protection: thermal insulation, fire, slash, stab, ballistic, pathogens, dust, toxic chemicals and biohazards, high visibility workwear.
6、 Medicine and Healthcare
In medicine and healthcare industry, non-woven geotextiles are largely used, as they can be easily sterilized. Geotextiles are largely used in manufacturing the disinfecting masks, wet wipes, masks, diapers, surgical gowns etc.
Produces in this sector are mainly disposable and include;
· Infection Control (surgery): disposable caps, gowns, masks and shoe covers,
· Wound Healing: sponges, dressings and wipes.
· Therapeutics: Transdermal drug delivery, heat packs
7、Geosynthetics
- Asphalt overlay
- Soil stabilisation
- Drainage
- Sedimentation and erosion control
- Pond liners
8、Filtration
Air & gas filters
Liquid - oil, beer, milk, liquid coolants, fruit juices….
Activated carbon filters
Origin and Advantages of non woven fabric felt
The origins of nonwovens are not glamorous. In fact, they resulted from recycling fibrous waste or second quality fibers 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 fulfill 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.
Post time: Dec-18-2018