What is the processing principle of needle punched non-woven fabrics?

Update:13 Oct 2021
The production of non-woven fabrics by acupuncture method is completely through a mechanical action, that is, the puncture action of the needle puncture machine, which strengthens the fluffy fiber web and obtains the strength.



The basic principle is:
Use triangular cross-section (or other cross-section) edges with barbed thorns to repeatedly puncture the fiber web. When the barbs pass through the web, they force the surface and local inner fibers of the web to penetrate into the interior of the web. Due to the friction between the fibers, the original fluffy web is compressed. When the felting needle exits the fiber web, the pierced fiber bundles detach from the barbs and stay in the fiber web. In this way, many fiber bundles entangle the fiber web so that it can no longer restore the original fluffy state. After many times of needle punching, a considerable number of fiber bundles are pierced into the fiber web, making the fibers in the fiber web entangled with each other, thereby forming a needle punched nonwoven material with a certain strength and thickness.
Needle-punched non-woven process forms include pre-needling, main-needling, pattern needling, ring needling and tubular needling.