There 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 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.
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.
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 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.
The particular set of properties that a non-woven fabric may have is dependent upon the combination of factors in its production. Each different ttype of non-woven will consist of different characteristics.
The range of characteristics include
- 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 tissue paper or many times thicker.
- They may also 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 goof to none at all.
- Some fabrics have excellent launderability; others have none. Some may be dry-cleaned.
Refrence for this article was taken from INDA, Assciation of the Nonwoven Fabrics Industry website.
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