This type of fabric is formed directly from fibers without spinning or weaving, and is commonly referred to as non-woven fabric, also known as nonwoven fabric, non woven fabric, or non-woven fabric. Non woven fabric is made of fibers arranged in a directional or random manner through friction, interlocking, bonding, or a combination of these methods, with the connotation of “not weaving”. Non woven fabric exists in the form of fibers within the fabric, while woven fabric exists in the form of yarns within the fabric. This is also a major characteristic that distinguishes non-woven fabric from other fabrics, as it cannot extract individual thread ends.
What are the raw materials for non-woven fabrics?
With the construction of mask production lines by PetroChina and Sinopec, and the production and sale of masks, people gradually understand that masks are also closely related to petroleum. The book ‘From Oil to Masks’ provides a detailed account of the entire process from oil to masks. Petroleum distillation and cracking can yield propylene, which is then polymerized to produce polypropylene. Polypropylene can then be further processed into polypropylene fibers, commonly known as polypropylene. Polypropylene fiber (PP) is the main fiber raw material for producing non-woven fabrics, but it is not the only raw material. Polyester fiber (polyester), polyamide fiber (nylon), polyacrylonitrile fiber (acrylic), adhesive fiber, etc. can all be used to produce non-woven fabrics.
Of course, in addition to the chemical fibers mentioned above, natural fibers such as cotton, linen, wool, and silk can also be used to produce non-woven fabrics. Some people often mistake non-woven fabrics for synthetic products, but this is actually a misunderstanding of non-woven fabrics. Like the fabrics we usually wear, non-woven fabrics are also divided into synthetic non-woven fabrics and natural fiber non-woven fabrics, except that synthetic non-woven fabrics are more common. For example, the cotton soft towel in the picture is a non-woven fabric made of natural fibers – cotton. (Here, the senior wants to remind everyone that not all products called “cotton soft wipes” are made of “cotton” fibers. There are also some cotton soft wipes on the market that are actually made of chemical fibers, but they feel more like cotton. When choosing, be sure to pay attention to the components.)
How is non-woven fabric made?
Let’s first understand how fibers come from. Natural fibers are naturally present in nature, while chemical fibers (including synthetic fibers and synthetic fibers) are formed by dissolving polymer compounds in solvents into spinning solutions or melting them into melts at high temperatures. The solution or melt is then extruded from the spinning pump’s spinneret, and the fine stream is cooled and solidified to form primary fibers. These primary fibers are then processed to form short or long fibers that can be used for spinning.
Weaving fabric is achieved by spinning fibers into yarn, and then weaving the yarn into fabric through weaving or knitting. How does non-woven fabric turn fibers into fabric without spinning and weaving? There are many production processes for non-woven fabrics, and the processes are also different, but the core processes all include fiber web formation and fiber web reinforcement.
Fiber networking
Fiber networking “, as the name suggests, refers to the process of making fibers into a mesh. Common methods include dry networking, wet networking, spinning networking, melt blown networking, and so on.
Dry and wet web forming are more suitable for short fiber web forming. Generally, fiber raw materials need to be pre treated, such as pulling large fiber clusters or blocks into small pieces to make them loose, removing impurities, mixing various fiber components evenly, and preparing before forming the web. Dry method generally involves combing and laying pre treated fibers into a fiber web with a certain thickness. Wet networking is the process of dispersing short fibers in water containing chemical additives to form a suspension slurry, and then filtering out the water. The fibers deposited on the filter will form a fiber web.
Both spinning and meltblown methods use chemical fiber spinning to directly lay fibers into a mesh during the spinning process. Among them, spinning into a web refers to the process where the spinning solution or melt is sprayed from the spinneret, cooled and stretched to form a certain fineness of filaments, which then form a fiber web on the receiving device. And meltblown networking uses high-speed hot air to extremely stretch the fine flow sprayed by the spinneret to form ultrafine fibers, which then gather on the receiving device to form a fiber web. The fiber diameter formed by melt blown method is smaller, which is beneficial for improving filtration efficiency.
Fiber mesh reinforcement
Fiber webs produced by different methods have relatively loose connections between internal fibers and low strength, making it difficult to meet usage needs. Therefore, reinforcement is also necessary. The commonly used reinforcement methods include chemical bonding, thermal bonding, mechanical reinforcement, etc.
Chemical bonding reinforcement method: The adhesive is applied to the fiber mesh through immersion, spraying, printing, and other methods, and then subjected to heat treatment to evaporate water and solidify the adhesive, thereby reinforcing the fiber mesh into a fabric.
Thermal bonding reinforcement method: Most polymer materials have thermoplasticity, which means they melt and become sticky when heated to a certain temperature, and then re solidify after cooling. This principle can also be used to reinforce fiber webs. Commonly used methods include hot air bonding – using hot air to heat the fiber mesh to achieve bonding and reinforcement; Hot rolling bonding – using a pair of heated steel rollers to heat and apply a certain pressure to the fiber web, so that the fiber web is bonded and reinforced.
Mechanical reinforcement method: As the name suggests, it is to apply mechanical external force to reinforce the fiber mesh. Commonly used methods include needling, hydroneedling, etc. Acupuncture is the use of needles with hooks to repeatedly puncture the fibrous web, causing the fibers inside the web to intertwine and reinforce each other. Friends who have played Poke Joy should not be unfamiliar with this method. By needling, fluffy fiber clusters can be poked into various shapes. The hydroneedling method uses high-speed and high-pressure fine water jets to spray onto a fiber mesh, causing the fibers to intertwine and be reinforced. It is similar to the needling method, but uses a “water needle”.
After completing fiber web formation and fiber web reinforcement, and undergoing certain post-processing such as drying, shaping, dyeing, printing, embossing, etc., fibers officially become non-woven fabrics. According to different weaving and reinforcement processes, non-woven fabrics can be divided into many types, such as hydroentangled non-woven fabrics, needle punched non-woven fabrics, spunbond non-woven fabrics (spun into webs), melt blown non-woven fabrics, heat sealed non-woven fabrics, etc. Non woven fabrics made from different raw materials and production processes also have their own unique characteristics.
What are the uses of non-woven fabric?
Compared to other textile fabrics, non-woven fabrics have a short production process, fast production speed, high output, and low cost. Therefore, non-woven fabrics have a wide range of applications, and their products can be seen everywhere, which can be said to be closely related to our daily lives.
Many disposable sanitary products used in our daily life use non-woven fabrics, such as disposable bed sheets, quilt covers, pillow cases, disposable sleeping bags, disposable underwear, compressed towels, facial mask paper, wet wipes, cotton napkins, sanitary napkins, diapers, etc. The surgical gowns, isolation gowns, masks, bandages, dressings, and dressing materials in the medical industry also rely on non-woven fabrics. In addition, non-woven fabrics are widely used in household wall coverings, carpets, storage boxes, vacuum cleaner filter bags, insulation pads, shopping bags, clothing dust covers, car floor mats, roof coverings, door linings, filter cloth for filters, activated carbon packaging, seat covers, soundproof and shock-absorbing felt, rear window sills, etc.
Conclusion
I believe that with the continuous innovation of non-woven fiber raw materials, production processes, and equipment, more and more high-performance non-woven products will appear in our lives to meet our diverse needs.
Dongguan Liansheng Nonwoven Fabric Co., Ltd., a manufacturer of non-woven fabrics and non-woven fabrics, is worthy of your trust!
Post time: Jul-28-2024