Nonwoven Fabrics Nonwoven fabrics are sheets of fiber […]
Nonwoven fabrics are sheets of fibers, continuous filaments, or chopped yarns of any nature or origin, that have been formed into a web and bonded together by any means except weaving or knitting.
Nonwoven fabrics boast some specific characteristics including but not limited to absorbency, strength, liquid repellency, resilience, softness, flame retardance, washability, cushioning, filtering, bacterial barrier, and sterility. These distinct properties are often combined to create fabrics suited for a broad spectrum of applications for specific jobs and deliver high performance across a wide range of applications. One can be surprised at so many ways one’s daily life is touched by nonwoven fabrics. Nonwoven fabrics have been extensively used in innumerable customer and industrial products, including absorbent hygiene products, apparel, home furnishings, healthcare, and surgical fabrics, construction, filtration, and engineering.
What Are the Different Types of Nonwoven Fabrics?
Nonwoven fabrics have long become an independent and technically sophisticated industry in its own right, and owe the prosperity of the industry to a great multiplicity of raw materials and process options. Nonwoven fabrics can be variously categorized by different classification methods. According to the practices of their production, nonwoven fabrics can be divided into a total of eight types.
1. Spunlace Nonwoven Fabrics
Spunlace nonwoven fabric is an essential type of nonwoven fabric. Spunlace nonwoven fabrics may sound unfamiliar, but indeed, products made from such spunlace nonwoven fabrics are widely used such as wet wipes.
The spunlace process, also known as hydroentanglement, is a manufacturing system for nonwoven fabrics that employs jets of water to entangle fibers and thereby provide fabric integrity. The spunlace process is free from binders and hence is ecologically harmless. Nonwoven fabrics manufactured with this process can maintain their original characteristics. The fiber is not damaged, and the appearance is closer to traditional textiles than other types of nonwoven fabrics. Spunlace nonwoven fabrics feature high strength, less fluff, good absorbability and permeability, softness and washability.
2. Heat-bonded Nonwoven Fabrics
Heat bonding can be performed in a few ways with different types of heating methods. In through-air bonding, hot fluid or air is forced through a preformed web. When the temperature of the fluid or the air is high enough, the fibers partially melt and form bonds where they come into contact. In infrared bonding, infrared light provides the heat required to melt the fibers partially. In ultrasonic bonding, friction between fibers causes partial melting of the fibers. In thermal point bonding, the preformed fiber web passes between heated calender rolls that are either smooth or embossed with a bonding pattern. On a smooth calender roll, bonding occurs wherever fibers cross each other, while on an embossed calendar roll, bonding occurs primarily between the raised areas. In all the processes mentioned above, the fundamental working principle is the same - the fibers are heated, bonded, and then cooled.
Heat bonding is suited for manufacturing nonwoven fabrics with thermoplastic fibers with a low melting temperature including homofil and bicomponent fibers, allowing a wide range of fabric properties and aesthetic to be obtained to satisfy a broad spectrum of needs. Heat bonding is much less energy-intensive, kinder to the environment, and more economical. Effective thermal contact offers significant energy and water conservation in contrast to latex bonding. It is more environmentally friendly as there are no remainders to be treated.
3. Air-laid Nonwoven Fabrics
Air-laid refers to a manufacturing technology that produces a web from short fibers by air. Separately loosened fibers and fine particles are uniformly dispersed in an airstream and laid on a metal mesh for bonding. Air-laid nonwoven technology generally uses latex emulsions, thermoplastic fibers, or some combination of both to bond the web’s fibers and increase the strength and integrity of the sheet. The process yields a paper-like fabric that is thicker, softer and absorbent. Air-laid nonwoven fabrics also boast more excellent tear resistance and tensile strength, particularly when wet. These physical characteristics of air-laid nonwoven fabrics make them suitable for many disposable absorbent applications in consumer, industrial, and institutional sectors such as household cleaning wipes and mops, adult incontinence products, and baby diapers.
4. Wet-laid Nonwoven Fabrics
The working principle of wet-laying is generally like paper manufacturing. The difference lies in the number of types of synthetic fibers present in wet-laid nonwoven fabrics. A dilute slurry