The factors that affect yarn quality are complex and diverse. Therefore, all aspects must be considered when optimizing yarn quality to obtain the best yarn quality.
The size of the negative pressure in the negative pressure tube is the most direct and critical factor affecting the quality of compact spinning yarn. The accumulation in the air box of the negative pressure fan will also affect the negative pressure of the negative pressure pipe. In daily production, the accumulation in the air box must be cleaned in time to maintain stable negative pressure. Usually, the negative pressure of compact spinning needs to be maintained at 24mbar~30mbar. 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. Under the same temperature and humidity conditions, when the negative pressure is 24mbar~27mbar, the negative pressure difference between the front and rear of the vehicle is approximately 1.5mbar~3.5mbar, and the hairiness difference is approximately 30%. The negative pressure fan should be selected reasonably according to the type of spinning machine. A 4.2kW negative pressure fan can be selected for a 1008-spindle spinning frame, and a 2.4kW negative pressure fan can be selected for a 512-spindle spinning machine. 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 reduce the impact of the negative pressure difference on yarn quality. Every time you wipe the car, you can turn on the negative pressure fan to suck out the dust accumulated in the negative pressure air duct and clean the negative pressure air duct.
During the compact spinning production process, due to the effect of suction and exhaust air, the workshop temperature will be significantly uneven at the front and rear of the car, and temperature and humidity will also affect hairiness. Usually, the number of hairiness and knots at the rear of the car is about 40% higher than that at 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 movement state of the whiskers on the negative pressure tube will also affect the yarn dryness. When the negative pressure is normal, whether the whiskers are transferring from the roller to the negative pressure tube or are moving on the negative pressure tube, The whiskers should remain straight and move in a converging state. However, due to factors such as excessive pressure on the cradle, accumulation of static electricity, and low negative pressure in the negative pressure tube, the whiskers may fall or tilt left and right in the “uncontrolled area” between the rollers and the negative pressure tube, and the movement state will be affected. changes occur. Therefore, the pressure of the compact spinning weighting arm should be small to prevent the accumulation of static electricity, maintain the surface smoothness of the rollers and top rollers, prevent tangling and sticking, and keep the negative pressure of the negative pressure tube normal. At the same time, try to use anti-static mesh rings with a reasonable mesh number.
The weighting arm pressure directly affects the yarn quality. Excessive weighting arm pressure can easily cause the front rubber roller to have a shortened service life, cause the front rubber roller to become concave, and may also cause mechanical waves of the rubber roller. The normal use cycle of the front rubber roller is about 2 months. When the pressure is too high, the roving will be weakly held after one and a half months of use, resulting in a rapid increase in breakage. Therefore, the pressure for compact spinning should not be too large. Generally, the pressure should be 160N/double spindles to 180N/double spindles.
The floating zone is a key factor affecting yarn quality. The position of the pressure rod should be moderate, and it should be ensured that the pressure rod cannot grind the front roller or long apron. Usually, if the pressure rod is positioned too far back, the floating area will be too large, and the fibers cannot be effectively controlled, and may even cause long circles; if the pressure rod is positioned too far forward, it will cause roving and the pressure rod will not be able to exert its effect. Some effects. The pressure rod grinds the roller and causes mechanical waves on the roller. In production, the forward stroke of the rubber roller is about 2mm~3mm, and the maximum should not exceed 3mm. 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 large top roller of 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 suction groove, affecting the yarn quality.
Reasonable draft distribution is also an important factor in improving yarn quality. When choosing the draft ratio, you cannot blindly pursue good yarn threads and neps. As the draft ratio continues to increase, the unevenness of the long segments of the yarn will also increase. When selecting the compact spinning process, beyond the critical draft multiple, you can appropriately increase the draft multiple in the back zone and increase the spindle speed, thereby increasing yarn output and improving efficiency.
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