In recent years, China's spunbond non woven fabric production technology has been improved, and the actual production efficiency is getting higher and higher, which has been recognized by many enterprises and researchers. However, the fiber strand problem of the production line has not been solved. Based on previous work experience, this paper summarizes the main reasons for fiber strand in spunbond non woven production line.

1.Fiber strand in nozzle Gallery of spunbond non woven fabric production line

From the point of view of practical work, the size of the main flow slit in the nozzle of the spunbond non woven fabric production line is the key content, and the actual requirements are also very strict. However, it can be seen from the actual processing that it is difficult to always maintain high accuracy within the 600mm length range. This accuracy is changing within a certain range, such as different air flows and inconsistent flow rates, which may lead to fiber strand problems. In addition, when using the nozzle, due to the obvious material leakage and fracture of the spinneret above, it is easy to cause the molten mass to enter the nozzle, increasing the possibility of horizontal air flow. In addition, in the process of corridor dredging, the staff will select the metal hook for operation, which is easy to cause the deformation of the upper lip of the throat, which also makes it more difficult to control the overall dimensional accuracy and increases the possibility of fiber strand. When cleaning the spinneret, workers usually choose to spray silicone oil on the spinneret. If overspray, silicone oil will also enter the corridor, causing a large number of fibers to bond to the inner wall, increasing its roughness, which will also lead to fiber strand problems.

2.Fiber strand caused by reciprocator in spunbond non woven fabric production line

When the two rollers move in one direction, the flow line will be significantly compressed and become more and more dense, which also makes the air flow faster and faster, causing the fiber to approach it. Affected by this, the bundle wire will also swing. Generally speaking, the direction of motion of the wire bundle and the swing roller is opposite. From a theoretical point of view, the strands at different stations can fall on the screen curtain in parallel, but this is not the case. This is mainly because the bundle wire cannot just fall in the middle of the spacing C. Even if it can be completed in a static state, the subsequent actions will change. At this time, the traction air flow faced by the whole system is turbulent, which makes the air flow around the round roll very chaotic, resulting in the following two situations: first, the two strands of strands will cross each other; Second, one of the strands will lean left and right for a while. From the nozzle outlet of the spunbond non woven fabric production line to the screen curtain of the screen forming machine, the strands can easily become fiber strand.

3.Fiber strand on the screen curtain of the screen forming machine in the spunbond non woven fabric production line

Generally speaking, there are three fiber strand modes for the screen curtain of the screen forming machine. The first is the fiber strand formed on the net curtain, which is similar to the cat tail and can roll on the net curtain. Secondly, in the rear screen curtain of the screen forming machine, the floc surface will turn over the screen layer. Finally, the floc surface on both sides of the screen curtain is in the flanging state after the screen forming machine. Strictly speaking, the latter two cases are not the problem of fiber strand, but the final effect, like fiber strand, will affect the surface quality of nonwovens. The main reason why the screen curtain of the screen forming machine closes the fiber strand is that the upper and lower air flow of the screen curtain of the screen forming machine is unbalanced. The main drafting power source of spunbond non woven fabric is air. During the subsequent operation, the flow introduced into the nozzle will be ejected from the nozzle outlet and transferred to the net curtain of the network machine. After entering the net curtain suction channel, it is pressurized by the air conditioning fan and discharged. At this time, a large amount of air is sprayed into the net curtain, but the amount of air inhaled by the air conditioning room is limited. The remaining air will flow to the front and rear along the surface of the net curtain, mainly in the form of cat tail tow, which eventually leads to fiber strand problems.

In a word, from the actual production of spunbond non woven fabric production line, it can be seen that the probability of fiber strand problem is very high. Especially when the nozzle sprays onto the net curtain and the air volume increases, the air intake in the air conditioning room is small, which eventually leads to the fiber strand problem in the production line. Understanding the specific causes of fiber strand problems in the spunbond non woven production line is helpful to solve this problem.