In the realm of modern materials, SS non woven fabric has emerged as a versatile and indispensable product, finding its way into numerous industries due to its unique properties and cost - effectiveness. As a trusted SS Non Woven Fabric supplier, I am excited to take you through the intricate process of how this remarkable material is made.
Raw Material Selection
The journey of SS non woven fabric begins with the careful selection of raw materials. Polypropylene (PP) is the most commonly used polymer for SS non woven fabrics. It is favored for its excellent chemical resistance, high melting point, and relatively low cost. The quality of the polypropylene resin significantly impacts the final properties of the non woven fabric. We source high - grade polypropylene pellets that have consistent molecular weight and purity. These pellets are free from impurities and additives that could potentially affect the spinning and bonding processes.
Extrusion
Once the raw materials are selected, the first major step in the manufacturing process is extrusion. The polypropylene pellets are fed into an extruder, which is essentially a large heated barrel with a screw mechanism. The screw rotates, pushing the pellets forward through the barrel. As the pellets move through the extruder, they are subjected to high temperatures, typically between 200 - 300 degrees Celsius. At these temperatures, the polypropylene melts and forms a viscous polymer melt.
The molten polymer is then forced through a spinneret, a device with numerous small holes. The spinneret is designed to create fine filaments of the molten polymer. The size and shape of the holes in the spinneret determine the diameter and cross - sectional shape of the filaments. For SS non woven fabrics, the filaments usually have a diameter in the range of 10 - 50 micrometers.
Spinning
After the filaments are formed through the spinneret, they enter the spinning zone. In this zone, the filaments are rapidly cooled by a stream of cold air. This rapid cooling solidifies the filaments, giving them their shape and strength. As the filaments cool, they are also drawn down, which further reduces their diameter and aligns the polymer molecules within the filaments. This molecular alignment enhances the strength and orientation of the filaments.
There are two main types of spinning processes used in the production of SS non woven fabrics: spunbond and meltblown. In the spunbond process, the filaments are continuously formed and laid down on a moving conveyor belt to form a web. The spunbond process produces relatively coarse filaments, which give the fabric good strength and durability. On the other hand, the meltblown process involves using high - velocity hot air to attenuate the filaments, resulting in much finer filaments. The combination of spunbond and meltblown layers in SS non woven fabrics, such as in SMS (spunbond - meltblown - spunbond) configurations, provides a balance of strength, filtration efficiency, and barrier properties.
Web Formation
Once the filaments are spun, they are laid down on a moving conveyor belt to form a web. The way the filaments are laid down affects the properties of the final non woven fabric. In the case of SS non woven fabrics, the web is typically formed in a random or semi - random pattern. This random arrangement of filaments gives the fabric uniform strength and properties in all directions.
The web can be formed using different methods. One common method is the use of an air - laid or wet - laid process. In the air - laid process, the filaments are carried by a stream of air and deposited on the conveyor belt. In the wet - laid process, the filaments are suspended in a liquid medium and then deposited on the belt as the liquid is drained away. The choice of web - forming method depends on the desired properties of the final fabric and the production requirements.
Bonding
After the web is formed, the next crucial step is bonding. Bonding is the process of joining the individual filaments together to form a cohesive fabric. There are several bonding methods used in the production of SS non woven fabrics.
Thermal Bonding
Thermal bonding is one of the most widely used methods. In thermal bonding, the web is passed through a pair of heated calender rolls or a hot air oven. The heat softens the surface of the filaments, causing them to fuse together at the points of contact. The temperature, pressure, and dwell time in the thermal bonding process are carefully controlled to achieve the desired level of bonding. Thermal bonding results in a fabric with good strength, stiffness, and dimensional stability.
Chemical Bonding
Chemical bonding involves the use of adhesives or binders to join the filaments. The adhesives can be applied to the web in various ways, such as spraying, dipping, or foam application. Chemical bonding can provide additional properties to the fabric, such as improved softness, flexibility, and resistance to certain chemicals. However, it may also add cost and complexity to the manufacturing process.
Needle Punching
Needle punching is a mechanical bonding method. In this process, a series of barbed needles are repeatedly punched through the web. The barbs on the needles entangle the filaments, creating a strong mechanical bond. Needle - punched non woven fabrics have a characteristic bulky and fibrous appearance. They are often used in applications where high strength and abrasion resistance are required, such as in geotextiles and automotive interiors.
Post - Processing
After the bonding process, the SS non woven fabric may undergo various post - processing steps to enhance its properties or prepare it for specific applications.
Coating
Coating is a common post - processing step. A thin layer of a polymer or other material is applied to the surface of the fabric. Coatings can provide properties such as water resistance, oil resistance, flame retardancy, and antistatic properties. For example, a waterproof coating can be applied to SS non woven fabrics used in outdoor applications, such as tents and awnings.
Printing
Printing can be done on the fabric to add patterns, logos, or other visual elements. This is often used in consumer products, such as packaging materials and home textiles. The printing process can be achieved using different techniques, such as screen printing, digital printing, or flexographic printing.
Slitting and Winding
Finally, the large rolls of SS non woven fabric are slit into the desired widths and wound onto smaller cores. This makes the fabric easier to handle, transport, and use in various applications. The slitting process is carried out using sharp blades, and the winding tension is carefully controlled to ensure a tight and uniform roll.
Applications and Our Offerings
SS non woven fabrics have a wide range of applications across different industries. In the medical field, they are used in surgical gowns, masks, and wound dressings. Their high barrier properties and breathability make them ideal for these applications. In the hygiene industry, SS non woven fabrics are used in baby diapers, adult incontinence products, and feminine hygiene products. They provide comfort, absorbency, and leak protection.
As a supplier, we offer a variety of SS non woven fabric products. Our Breathable Composite Non - woven Fabric is designed to provide excellent breathability while maintaining good strength and barrier properties. Our PP Spunbond Nonwoven Fabric is known for its high quality and durability. And our 15g - 50g Sss Spunbonded Non Woven Fabric offers a range of weights to suit different application requirements.
Contact for Procurement
If you are in the market for high - quality SS non woven fabrics, we invite you to reach out to us. Our team of experts is ready to assist you in selecting the right product for your specific needs. Whether you need a large - scale supply for an industrial application or a custom - made solution for a unique project, we can provide you with the best products and services.
References
- Nonwovens: An Introduction by David J. Bryant
- Handbook of Nonwovens by Richard K. Rushton
- The Nonwovens Handbook edited by John E. Adanur