As a new ring spinning method to improve yarn quality, compact spinning has attracted more and more attention. How to improve product quality has attracted more and more attention from spinning enterprises. This article mainly introduces several common factors that affect the quality of compact spinning yarn.
The exhaust volume of the negative pressure fan and the negative pressure of the negative pressure pipe
The size of the negative pressure of the negative pressure pipe affects the compact spinning Yarn quality is the most direct and critical factor. Facts have proved that the exhaust volume of the negative pressure fan will directly affect the negative pressure; in addition, the accumulation in the air box of the negative pressure fan is also a key factor affecting the negative pressure of the negative pressure pipe. In daily production, it is necessary to clean the bellows accumulation in time to keep the negative pressure stable.
According to actual testing and production findings, the negative pressure of compact spinning needs to be maintained at 2.4 kPa ~ 3.0 kPa. If the negative pressure is too low, the breakage rate will increase, the hairiness will increase, the length of the hairiness will be long, and the hairiness unevenness will be large. According to actual measurements, under the same temperature and humidity conditions, when the negative pressure is between 2.4 kPa and 2.7 kPa, the negative pressure difference between the front and rear of the car is about 150 Pa to 350 Pa, and the hairiness difference is about 30%. For example, the number of hairs at the tail end of C 7.29 tex yarn is 812.20 hairs/m, while that at the front end is 1065.40 hairs/m. Production practice has proved that the 1008-spindle spinning frame can choose a 4.2 kW negative pressure fan, and the 512-spindle spinning frame can choose a 2.4 kW negative pressure fan. Appropriately increasing the speed of the negative pressure fan can reduce the negative pressure difference between the front and the rear of the car and minimize the impact of the negative pressure difference on yarn quality. Every time you sweep the car, you can remove 6 to 8 negative pressure tubes on both sides of the rear end, turn on the negative pressure fan, and suck out and clean up the dust accumulated in the negative pressure air duct.
The movement state of the whiskers on the negative pressure tube
The movement state of the whiskers on the negative pressure tube affects the yarn The important factor of the line stem is that under normal negative pressure conditions, during the process of transferring the whiskers from the roller to the negative pressure tube and during the movement on the negative pressure tube, the whiskers are relatively straight and continuously gathered. Status moves. However, affected by certain factors, the movement state of the whiskers will change.
The movement state of the whiskers during the transfer from the roller to the negative pressure tube
In actual production, due to excessive pressure on the cradle Factors such as large, static electricity accumulation, poor surface of the rubber roller, and low negative pressure of the negative pressure tube cause the sliver to fall or skew left and right in the “uncontrolled area” between the roller and the negative pressure tube, and the yarn stem will be significantly affected. Influence. Therefore, the pressure of the concentrated spinning cradle should be kept small to prevent the accumulation of static electricity, maintain the surface roughness of the rollers and cots, treat the cots with ultraviolet rays to prevent tangling, and keep the negative pressure of the negative pressure tube normal.
The movement state of the whiskers on the negative pressure tube
In actual production, sometimes a large increase in hairiness and breakage will occur The main reason for the phenomenon that the rate increases sharply or all ends are broken is that the negative pressure fan has not been started or the accumulation of dust in the negative pressure air box has not been cleaned in time for a long time, causing the negative pressure to be too small. Sometimes it happens that some single spindles have a high breakage rate or cannot spin normally. The main reason is that the accumulation of flowers at the output end of the suction groove of the negative pressure tube is caused. Just clean the accumulation of flowers in the grid circle. At the same time, Try to use anti-static mesh rings and choose mesh rings with a reasonable mesh size.
The influence of temperature and humidity in the workshop
During the compact spinning production process, due to the effect of suction and exhaust air, the temperature in the workshop changes at the front of the machine. There will be obvious unevenness at the rear of the car, and this unevenness will show seasonal differences. The temperature difference in winter is about 2 ℃ ~ 4 ℃, and in summer it is about 3 ℃ ~ 6 ℃. Temperature and humidity are an important factor affecting hairiness. According to actual measurements, the number of hairiness and neps at the rear of the car is about 40% higher than that at the front of the car. Therefore, keeping the temperature and humidity in the workshop normal and reducing the temperature and humidity difference is an important measure to improve product quality.
Weighting arm pressure
The weighting arm pressure directly affects the yarn quality. Excessive weighting arm pressure can easily cause damage to the front rubber roller. The shortened service life will cause the front rubber roller to be concave, and mechanical waves of the rubber roller may also occur. The normal use cycle of the front rubber roller is about 2 months. When the pressure is too high, problems with the roving holding will occur after one and a half months of use, resulting in a rapid increase in breakage. Therefore, the pressure for concentrated spinning should not be too large, and is generally controlled between 160 N/double spindles and 180 N/double spindles.
The impact of spinning technology on yarn quality
The size of the floating zone
The floating zone is a key factor affecting yarn quality. The size of the floating area should be consistent, and the pressure rod should be in a moderate position. The pressure rod should not grind the front roller or grow the rubber ring. If the pressure rod is positioned too far back, the floating area will be too large, and the fiber cannot be effectively controlled, and the apron may even be worn. If the pressure rod is positioned too far forward, the roving will “run up” and the pressure rod will not be able to perform its function. If the pressure rod grinds the front roller, it will also cause mechanical waves on the roller. In production, the forward stroke of the rubber roller is approximately 2 mm to 3 mm, and the maximum should not exceed 3 mm. If the forward stroke is too large, it is easy to form an anti-enveloping arc, resulting in a decrease in yarn quality and an increase in end breaks. . Excessive floating area in compact spinning can easily cause the front rubber roller to press the grid ring. When the whiskers move to both sides of the yarn guide stroke, the whiskers swing left and right at the air suction groove, affecting the yarn quality.
Spinning yarn draft ratio
Reasonable draft distribution is also an important measure to improve yarn quality. According to experiments, when spinning 11.7 tex pure cotton yarn, there are obvious differences in yarn quality with different draft ratios in the back area.
When choosing the draft ratio, you cannot blindly pursue good yarn lines and neps. As the draft ratio continues to increase,As �� increases, the unevenness of long segments in the yarn will also increase. When selecting the condensed spinning process, beyond the critical draft multiple, you can appropriately increase the draft multiple in the back zone and increase the spindle speed appropriately, thereby increasing yarn output and improving efficiency.
In short, the optimization of yarn quality is a complex project, and the factors that affect yarn quality are also complex and diverse. Therefore, all aspects must be considered when optimizing yarn quality to obtain the best yarn quality. </p
