Technical characteristics and market distribution of meltblown and spunbonded non-woven fabrics

Spunbond and meltblown fabrics are two new products in the field of non-woven fabrics in recent years. The preparation technologies are all derived from the research on fibers and polymers. The two technologies are very similar in main aspects, but it is worth emphasizing that the two technologies are very different in some aspects. Both the spunbond method and the meltblown method adopt a one-step forming process to produce fabrics directly from polymer resins. This is the similarity between the two. Can roughly describe these two processes. The melt blowing method is to directly form a web from the polymer, and the polymer melt extruded by the screw extruder is blown by high-speed and high-temperature airflow or other means (such as centrifugal force, electrostatic force), so that the melt stream is extremely stretched The very fine short fibers are then gathered on a web forming drum or web curtain to form a web, and finally self-adhesive to be reinforced to make a non-woven fabric. The specific process is to melt the polymer slices through a screw extruder, and then extrude them from the spinneret holes of the spinneret after being filtered. Under the jet of high-speed hot air, they are stretched to form extremely thin Short fibers, these short fibers are absorbed and condensed on the mesh curtain. Because the threads have not been cooled, they can still maintain a higher temperature after they are condensed into a web. Through the adhesion between the fibers, the web can be reinforced to form a melt blown cloth. It can be further strengthened by hot rolling bonding method as required. At present, most of the raw materials used in the melt-blown method are polypropylene. Polyester or polyamide can also be used. In order to make the thin stream of melt get better draft in the hot air blowing process, the melt index of the raw materials is required to be as low as possible. It may be higher. The spinning temperature, blowing air flow and speed used for raw materials with different melt indexes are changed accordingly to ensure that the thread is fully drawn and improve the quality and performance of the fiber. The raw materials of vinegar that can be used in the melt blown method are polypropylene, polyester, polyethylene, polystyrene and polyphenolamine, etc. The most commonly used is polypropylene. Because this method uses high-pressure hot air drafting, it is better to use raw materials with low temperature control and good flow properties. That is, the use of polymers with a higher melt index is beneficial to increase production and reduce energy consumption. The melt index (MFI) of polypropylene is generally above 18. Meltblown process: polymer feeding, melt extrusion, fiber formation, fiber cooling, forming a net, and strengthening into a cloth. The whole set of equipment for the production of meltblown non-woven fabrics consists of the main engine, heating system, lubrication system, hydraulic system, cooling system, and electrical control system. The host is the core of the whole set of equipment, which mainly includes feeding system, screw extruder, filter screen, spinning assembly, spinneret die, receiving net system, and winding mechanism. 2 Meltblown production line spunbond technology uses a similar fiber-grade polymer, which is extruded through a spinneret with a linear or circular arrangement of spinneret holes, and the polymer stream is cooled by air and mechanically stretched. The rollers are stretched to obtain the required filament diameter. Generally, the diameter of the continuous filament is 15-20μm, and then the filament is collected on the conveyor belt to form a net, and the final bonding step (needle punching or thermal bonding) is obtained. High-strength fiber mesh. Spunbond processing technology can be summarized as the following two points: 1. Polymer chips are fabricated at one time. 2. All spunbond webs are obtained on a complete and continuous production line. The properties and uses of fabrics obtained by different processes are different. Due to the smaller fiber diameter of the melt-blown bonded fabric, the filtering performance is better (it can filter substances with a smaller diameter), and it has an ultra-fine filtering effect. This is the biggest feature of melt-blown non-woven fabrics, so it is often used as a breathable separator. Block material. Among all the fabrics made by melt-blown method, more than half are used as filter materials in the medical, pharmaceutical and industrial fields. Absorbent materials, absorbent materials, wipes and packaging materials are the second largest consumer areas. 'Meltblown nonwovens: an expert in ultra-fine filtration. Textile and Apparel Weekly, February 1, 2010' Spunbond is used to prepare stronger materials, which are used for napkin-like covering materials (polypropylene), roofs Backing material (poly 3 vinegar), automotive industry materials and carpet backing (poly vinegar), and disposable medical, pharmaceutical, health care and environmental protection products (polypropylene) and other fields. About two-thirds of spunbond non-woven fabrics in the United States are made of polypropylene, and napkin-like covering materials are the largest consumer part, accounting for almost half of all spunbond polypropylene products in the United States. Medical treatment, medicine, carpet backing, furniture and bedding constitute the second largest consumer of polypropylene spunbonded non-woven products in the United States. In Japan, due to the rapid increase in the consumption of non-woven fabrics in the fields of tarpaulin, medical and health care products, the growth rate of polypropylene spunbond non-woven fabrics is as high as 10%), and the proportion of non-woven products has been from 1985 13% in the year) rose to 36% in 1992. In 1992, the production of polypropylene spunbonded non-woven fabrics in Japan was more than 6 times that of 1985.