How to identify non-woven fabric?

Non-woven fabric is a material made using a non-traditional textile process. Its fibers are directly bonded together through mechanical, thermal, or chemical methods, forming a web-like structure. Identifying non-woven fabric can be done through various observations and tests. First, observe its appearance. The fibers in non-woven fabric are randomly arranged, unlike the neatly arranged warp and weft threads of woven fabrics and the loops of knitted fabrics. The edges of non-woven fabric tend to fray easily, and the fibers loosen when torn by hand, while the edges of woven and knitted fabrics are usually more robust.

Touching the fabric can reveal its characteristics. Most non-woven fabrics are relatively stiff, especially those with a high gram weight, but softer types also exist, such as medical SMS non-woven fabric. It's important to note that non-woven fabrics generally lack elasticity unless elastic fibers are specifically added, which is significantly different from knitted fabrics. Knitted fabrics have good stretchability, while the softness or stiffness of non-woven fabrics depends on the fiber material.

The burning test is one of the most reliable methods for identifying materials. Take a small sample and ignite it, observing the phenomena during combustion. If it's polypropylene (PP) non-woven fabric, it will melt and drip, the flame will be blue-yellow, and it will emit an odor similar to paraffin. A hard residue will remain after burning. Polyester (PET) non-woven fabric will produce black smoke, melt and drip, and emit a sweet smell. The residue will be black, hard beads. If it's viscose fiber or cotton non-woven fabric, it will burn faster, without melting or dripping, the smell will be similar to burning paper, and the ash will be fine.

Light transmittance testing can also be used to identify non-woven fabrics. Place the fabric under a light source and observe. The light transmittance of non-woven fabric is uneven due to the random distribution of its fibers; while the light transmittance of woven fabric is more uniform because of the regular arrangement of its warp and weft threads.

The durability of non-woven fabrics is generally not as good as traditional textiles. Ordinary non-woven fabrics, such as PP spunbond non-woven fabric, are prone to deformation, pilling, and even tearing when wet. Water-jet non-woven fabrics (such as wet wipes) are relatively durable, but they will still loosen after repeated washing. Woven and knitted fabrics, on the other hand, can be washed repeatedly without easily being damaged. For more precise analysis, professional testing methods can be used. Under a microscope, the fibers of nonwoven fabrics are arranged randomly and lack a yarn structure. Infrared spectroscopy (FTIR) can determine the material composition, such as PP, PET, or cotton.

In summary, the key to identifying nonwoven fabrics lies in observing their fiber arrangement, edge characteristics, feel, burning properties, and water resistance. Common applications of nonwoven fabrics include shopping bags, medical protective clothing (PP spunbond nonwoven fabric), surgical gowns and masks (SMS nonwoven fabric), wet wipes (spunlace nonwoven fabric), and mask filter layers (meltblown nonwoven fabric). Through these methods, nonwoven fabrics can be accurately distinguished from traditional woven and knitted fabrics.