New technology for non-woven spunbond production

Nowadays, due to overcapacity, non-woven spunbond producers are facing fierce competition in some markets, and price wars have reduced their originally thin profits. On the other hand, in some markets, the supply of products processed with non-polyolefin raw materials such as polyester is in short supply, and the profits are far above average. Obviously, which technology a manufacturer adopts largely determines the market direction of its products. Moreover, some recent market development trends indicate that two-component technology is increasingly used in non-woven spunbond products, and its unique characteristics cannot be obtained with a single raw material. For example, some bi-component fiber products undergo further processing after spunbonding, which will have a textile effect due to ultrafine fibers, which can be comparable to traditional textiles and even replace them in some areas. Therefore, from the manufacturer's point of view, as important as the quality and reliability of the equipment are the technical capabilities and flexibility of the equipment. Neumag is one of the leading manufacturers of synthetic fiber processing equipment. It has accumulated more than 50 years of fiber spinning equipment and processing know-how, including two-component fiber processing technology. In order to be able to better respond to customer needs, Neumag decided to launch a new technology Ason spunbond technology in the non-woven spunbond market. In 2003, an experimental production line with a width of 1.2 meters was put into operation in December 2003. The unique design of the spinning rod and the distribution of the melt at the bottom of the spinning rod and the pipe integrated in the spinning roller are unique in that: the drum is round and uses Daosheng heating; spinning pump and melt The pipe is built into the heating part of the drum; the insulation between the drum and the spinning box is very strong and effective; multiple strands of melt flow from the main pipe to the spinning pump and spinning pump through the same path, the same length, diameter and curvature of the pipe. The entrance of the silk assembly; the distance of the entrance of each spinning assembly is 150 mm. The distribution of the melt from the component inlet to each spinneret is the same, and the temperature and heating conditions of the melt in the entire drum are therefore kept uniform. The advantages of this design are obvious. In the range of 180 to 310 degrees Celsius, the temperature difference of the entire drum is less than 1 degree Celsius, which is very important in the high-speed spinning process. The same path of the melt ensures the same residence time and conditions, and also makes the equipment suitable for different processing speeds, temperatures and materials used. For occasions where more flexibility is required in production, this advantage is even more important. The drafting trough used in this experimental production line has two characteristics: ultrasonic nozzle; the length of the trough cavity, that is, the distance from the nozzle outlet to the bottom of the trough is less than 210 mm. From the computer simulation of the airflow in the drafting trough, in addition to the supersonic velocity in the drafting trough cavity, you can also see the 'wave' or 'folding wing'-like airflow at the lower part of the notch, which creates a 'shape' on the filament The draft airflow has the same shape as the airflow in the air. This kind of'forming' draft, which increases exponentially with the air velocity, constitutes the vast majority of the total drafting force of the drafting notch, and also makes the entire device strong and efficient. The adjustable spinning length and forming distance experimental production line has two adjustable platforms, one with spinning rod and the other with drafting groove. The spinning length is determined by the distance between the spinnerets. The size of the drafting slot can be adjusted by lowering the platform height separately, and the forming distance can also be adjusted by moving the top and bottom platforms together. It should be emphasized that the spinning length is less than 1.5 meters, preferably between 300-700 mm, which is one of the unique features of Ason technology. The ideal and minimum spinning length selected according to different product requirements maximizes the drafting force and obtains a high spinning temperature, thereby ensuring the required high spinning speed (polypropylene higher than 6000 m/min, The spinning speed of PET exceeds 8000 m/min), which also enables this equipment to process filaments of different fineness and different raw materials. Needle planting and barrier technology for bi-component fiber production The key to bi-component fiber production is the design of the spinning component so that two different polymer melts extruded from two different extrusion ports can reach the spinneret and form The two-component single fibers of different shapes will not come together before. There are usually three different techniques to design spinning components with different cross-sections. 1 Thin layer (plate) technology: A multilayer baffle is used to guide two polymer melts independently through the assembly, forming fibers just before entering the micro holes of the spinneret. Advantages: All required cross-sections of bicomponent fibers can be produced by using the same component with different layers of baffles, which is economical and flexible. Disadvantages: It is easy to be affected by raw material parameters such as different melt viscosity (whether the viscosity matches) and repeated operations, and it is also difficult to seal long and different layers.