The factors affecting yarn quality are complex and diverse. Therefore, when optimizing the yarn quality, we must consider it in order to obtain the best yarn quality.
The negative pressure of the negative pressure tube is the most direct and critical factor affecting the quality of compact spinning yarns. The accumulated flowers in the air box of the negative pressure fan will also affect the negative pressure of the negative pressure pipe. In daily production, the accumulated flowers in the air box must be cleaned in time to keep the negative pressure stable. Generally, the compact spinning negative pressure needs to be maintained at 24 mbar to 30 mbar. If the negative pressure is too low, it will cause an increase in the head breakage rate, an increase in hairiness, a long hairiness, and a large unevenness of hairiness. Under the same temperature and humidity conditions, when the negative pressure is between 24mbar and 27mbar, the negative pressure difference between the front and rear of the car is about 1.5mbar ~ 3.5mbar, and the hairiness difference is about 30%. The negative pressure fan should be reasonably selected according to the type of spinning machine. The 1008 spindle spinning machine can choose a 4.2kW negative pressure fan, and the 512 spindle spinning machine can choose a 2.4kW negative pressure fan. Properly increasing the speed of the negative pressure fan can reduce the negative pressure difference between the head and the rear, and reduce the effect of the negative pressure difference on the yarn quality. Each time you lift the car, you can turn on the negative pressure fan to suck out the accumulated flowers in the negative pressure air cylinder and clean the negative pressure air cylinder.
During the process of compact spinning, due to the effect of suction and exhaust, the temperature of the workshop will be significantly uneven at the front and rear of the car, and the temperature and humidity will also affect the hairiness. Generally, the number of hairiness and tingles on the tail of the car is about 40% higher than that of the front of the car. Therefore, maintaining normal temperature and humidity in the workshop and reducing the temperature and humidity difference can improve product quality. The state of movement of the sliver on the negative pressure tube will also affect the yarn sliver dryness. Under normal circumstances, whether the sliver is in the process of the roller transferring to the negative pressure tube or on the negative pressure tube, The sliver should be kept straight and moved continuously. However, due to factors such as excessive pressure of the cradle, static electricity accumulation, and low negative pressure of the negative pressure tube, the sliver has fallen or left and right skewed in the "uncontrolled area" between the roller and the negative pressure tube. Changed. Therefore, the compact spinning cradle pressure should be small to prevent the accumulation of static electricity, maintain the surface finish of rollers and rollers, prevent sticking, and maintain the normal pressure of the negative pressure tube. At the same time, try to use anti-static, reasonable mesh number ring.
The cradle pressure directly affects the yarn quality. Excessive cradle pressure may easily shorten the life of the front rubber roller, the front rubber roller is concave, and it may also cause mechanical wave of the rubber roller. The normal use period of the front rubber roller is about 2 months. When the pressure is too large, the roving will not be held properly for one and a half months, resulting in a rapid increase in broken ends. Therefore, the pressure for compact spinning should not be too large. Generally, the night control is 160N / double spindle ~ 180N / double spindle.
The floating zone is a key factor affecting the quality of the yarn. The position of the pressure rod should be moderate, and the pressure rod must not be worn by the front roller and long apron. Generally, the position of the pressure rod will cause the floating area to be too large, and the fiber cannot be effectively controlled, and even the phenomenon of abrasion and inflammation will occur; while the position of the pressure rod too far will cause the roving phenomenon, and the pressure rod should not be used Some effect. The pressure rod wears the rollers, and also causes the roller mechanical waves to appear. In production, the rubber roller's forward stroke is about 2mm ~ 3mm, and the maximum should not exceed 3mm. If the forward stroke is too large, it will easily form an anti-surrounding arc, resulting in a decrease in yarn quality and an increase in end breaks. If the floating area is too large, it is easy to cause the front rubber roller to press the grid circle. When the sliver moves to both sides of the yarn guide, the sliver swings left and right at the suction groove, which affects the yarn quality.
Reasonable drafting distribution is also an important factor for improving yarn quality. When selecting the draft multiple, you cannot blindly pursue good yarn slivers and neps. As the draft multiple continues to increase, the unevenness of the long and medium segments of the yarn will increase. When the compact spinning process is selected, in addition to the critical draw multiple, the draw ratio in the back zone can be appropriately increased to increase the spindle speed, thereby increasing the yarn output and the efficiency.
