Non Woven Fabric Processing Technology-Spinning Fusion(Part 1)

Spinning fusion is the most widely used one-step spinning forming process for forming nonwoven fabrics. Spunbond non-woven fabrics are formed by continuous filament fibers, with high production line speed, high product strength and good dimensional stability, but low bulkiness, poor uniformity and surface coverage.

The spunbond method combines fiber spinning technology and nonwoven forming technology. Using the principle of melt spinning, the raw materials are melted and kneaded by an extruder and then extruded from the spinneret of the spinning head to form a thin stream of melt . High-speed quench air is used to cool the extruded melt stream, and at the same time, the fiber is stretched by the drawing air flow during the cooling process, forming a continuous filament with higher strength and more stable performance. After the filaments are split into a uniform monofilament structure, they are laid on a net curtain with negative pressure to form a nonwoven web. The fiber web then passes through the subsequent reinforcement device for hot-rolled reinforcement, needle-punched reinforcement or spunlace plus fixed type, and then is wound up by the winding device to obtain the product. The key steps are melt spinning, air drawing of primary fibers, fiber forming and web setting.

1. Melt spinning

The raw materials need to be dried in advance to avoid degradation when heated and melted at high temperature, especially to avoid the vaporization of water at high temperature to form "bubble silk", which can cause wool or broken ends, affecting product quality and normal production. The spinning process is controlled mainly from the following aspects.

Spinning temperature control: mainly to control the temperature of spinning components such as spinnerets. Appropriate spinning temperature should keep the melt fluid enough to ensure smooth spinning, and the uniformity and spinnability of the melt is high, so that the subsequent air flow drawing process can be carried out smoothly, and the fiber orientation is high. The spinning temperature is controlled between the melting point and the decomposition temperature. Properly increasing the spinning temperature can improve the melt fluidity.

Control of spinning melt pressure: mainly to control the pressure of the melt in the spinning box. If the melt pressure is too low, the melt flow is not evenly distributed on the spinneret, and the extruded melt fine flow diameter is not uniform. If the melt pressure is too high, it is easy to cause the melt of the spinneret orifice to burst.

Spinning speed control: The spinning speed affects the size and uniformity of the fiber linear density and the quality of the nonwoven fabric. The spinning speed is too low, and the extruded melt stream is cooled too quickly, resulting in easy to break the yarn. However, the spinning speed is too high, and the melt stream cannot be cooled in time, which leads to the occurrence of doubling and affects the quality of the nonwoven fabric.

The above information is provided by floor protection mat factory.