Nonwoven technology is a kind of material processing technology that originates from textiles and goes beyond textiles. Different nonwoven process technologies (non woven machine) have their own corresponding process principles. But from a macro point of view, the basic principles of nonwoven technology are the same, which can be described by its technological process. Generally, it can be divided into the following four processes: (1) fiber preparation (2) network formation (3) reinforcement (4) post-finishing.
Nonwoven products
1. Spunbond nonwoven fabric. The fibers in the fiber web is continuous filament with high strength and similar vertical and horizontal properties, but its uniformity and surface coverage are poor. Spunbond process products are mainly S, SS.
2. Meltblown nonwoven fabric. Ultra-fine fiber structure, small fiber diameter, small filtration resistance, high smearing efficiency, good surface girdle performance, but low base performance and poor wear resistance. Meltblown process products are mainly M.
3. Spunmelt nonwoven fabric. Spunmelt method, also called composite method, combines the excellent properties of spunbond and meltblown nonwoven fabrics, and makes up for the shortcomings of spunbond nonwoven fabrics with poor uniformity and low meltblown nonwoven fabric strength. Spunmelt nonwoven products mainly include SMS, SMMS, SSMMS, etc.
Process flow comparison
1. Spinning principle of spunbond method: At present, spunbond method is mainly based on melt spinning. Relying on the action of air flow, the polymer is drawn and thinned into filament fibers, and the filament fibers form turbulent fibers at the exit of the drawing channel with the help of the drawing air flow. The filaments fall on the screen curtain of the net laying machine like a veil, through the suction effect of the suction fan. The filaments are evenly adsorbed on the screen curtain to prevent the filament and a part of the airflow from hitting the screen curtain and rebounding and destroying it. The evenness of the web. The fiber web softens and melts when subjected to pressure and heat in a hot rolling mill, and is welded together at the nip point to form a nonwoven fabric with a certain strength.
2. Spinning principle of meltblown method: Meltblown nonwoven fabric production technology is to extrude, melt and plasticize polymer resin through a screw extruder, and then accurately measure it by a metering pump and deliver it to the meltblown die head through a melt pipeline. Through the spinneret assembly, the ultra-fine short fiber pheasants are obtained under the development and injection of high-speed and high-pressure hot air flow, which spreads with the volume expansion of the jet air flow, and is evenly spread on the laying machine under the action of the suction fan. The heat of the drafting airflow and its own waste heat are used to bond each other on the web forming device to form a meltblown fabric. Further hot roll bond reinforcement is available as required.
Although the product properties of spunbond nonwoven fabrics and meltblown nonwoven fabrics are completely different, their production processes are very similar:
The production process of spunbond nonwoven fabrics is as follows: raw material conveying, screw melting, melt filtration, melt metering, spinning, cooling and drafting, wire laying, hot rolling, and winding.
The production process of meltblown nonwoven fabrics is as follows: raw material conveying, screw melting, melt filtering, melt metering, spinning, hot air drawing, laying, winding.
Therefore, the emergence of spunbond/meltblown composite material, which is a combination of spunbond process and meltblown process, makes full use of the advantages of both technologies. In a production line, there can be one or more sets of web forming devices using the same or different raw materials and the same or different processes. Based on the spunbond method, there are currently SMS. SMMS. SSMMS and other spunmelt methods that are not only one-step web-forming production lines for fabric making. The combination of the two process methods has obvious effects on increasing yield, improving product quality and performance.
3. Spinning principle of spunmelt method: In the production of spunmelt nonwovens, that is, on the same production line, there are spunbond die and meltblown die at the same time, giving full play to the spinning advantages of spunbond and meltblown , to produce high-quality composite nonwoven fabrics.