The function of the draw frame is to improve the internal structure of the fiber sliver, thereby increasing the uniformity of its long segments, while reducing the weight unevenness. Therefore, the maintenance and maintenance of the draw frame is closely related to the product quality. Let us share some relevant experience.
Method 1: Regularly check the roller bearing status to reduce the generation of mechanical waves
Coarse roughing process is one of the key processes for spinning companies to control and stabilize the quality of semi-finished products. The mechanical wave of the process is particularly important for the subsequent process and even the quality of the fabric. Therefore, it is necessary to strengthen equipment inspection and strictly control. By analyzing and processing the causes of mechanical waves at 13 cm to 15 cm and 78 cm to 80 cm on the spectrogram of the FA317 draw frame, the CV value of the draw frame was significantly improved.
The mechanical wave reflected on the spectrogram is the “chimney”, which generally occupies a channel, and when the frequency of the mechanical wave is between two adjacent channels, the two adjacent channels will be touched, so it is displayed on the spectrogram Two adjacent channels are occupied; in individual cases, the slightly fluctuating channels may change slightly, and the "chimney" may occupy 3 or 4 channels. Mechanical waves have inherent wavelengths and are accompanied by harmonics. Therefore, only the fundamental wave analysis is the most accurate.
In order to prevent the generation of mechanical waves, it is necessary to regularly check the status of the roller bearing, regularly inspect the wear of the shaft and hole, the looseness of the key and keyway, the wear and shape of the gear tooth tip, and the sloshing of the bearing, and regularly lubricate the bearing components. To ensure that there is no shortage of oil or damage; regularly check the tightness of the toothed belt of the transmission roller, clean up the dirt embedded in the tooth gap in time, and find out if the gear mesh is poorly engaged or worn.
In specific work, the lubricating state of the rollers should be regularly checked and the curved rollers should be corrected; regularly lubricate, clean the bushings, and correct the rubber rollers to eliminate the drafting mechanical waves caused by the poor operation of the bushings and rubber rollers; The inspection of the transmission toothed belt requires that the toothed belt is not worn and has a proper tightness; when the variety is changed, the rubber roller is replaced and checked to ensure the roughness and straightness of the surface; the draft channel is strictly checked during the handover to prevent the shaft The sleeve and rubber roller are beating.
Method two: Maintain key equipment to play a self-leveling function
The FP sensor is installed at the bell mouth detection device of the FA322B high-speed draw frame. It is a precision measurement mechanism. When cleaning and handling the fault of the bar, it will be scratched or damaged by carelessness, resulting in inaccurate detection signals. Or it may cause frequent alarms of the quality monitoring system and affect the efficiency of driving. Therefore, use special tools for disassembly and cleaning, and it is strictly prohibited to scratch or hit it with a hard object.
Make sure that the air supply to the FP sensor is free of oil, debris, and dry. However, some users do not pay attention to this, and the use of old-style air compressors causes oil pollution in the air source, causing a short circuit of the bridge circuit in the FP sensor, and eventually making it unusable.
The T / G roller device is mainly responsible for the detection of the thickness signal of the feeding sliver. If the cleaning is not carried out from time to time, it will cause the cotton to wrap around the grooves of the concave and convex rollers. The longer the time, the more cotton will gather. Finally, the signal given by the displacement sensor is deviated, which affects the leveling effect of the whole machine.
Encrypt the operation panel to prevent unauthorized operation by unrelated persons. However, some users do not have strict password management, which causes many people to operate at will, which in turn causes abnormalities in the leveling system and produces waste slivers. In addition, we must develop a good habit of cleaning up the waste cotton in the suction box in a timely manner, refueling the high-speed rotating mechanical parts regularly, regularly changing the oil in the gear box, and cleaning the air duct and fan blades of the inverter in time.
With the development of the spinning process towards high speed, large package, short process, and the continuous improvement of the market's requirements for yarn and fabric quality, high-speed draw frames with self-leveling devices are receiving more and more cotton textile companies Welcome. Practice has proved that using the FA322B high-speed self-levelling draw frame after combing a combing process shortens the spinning process, ensures the spinning quality, reduces labor costs, and also improves the sliver overmature and rotten The problem.
Method three: Pay attention to parameter settings to ensure dynamic closed-loop monitoring
FA387 is a digital high-speed draw frame. It can set the machine's draft, speed, fixed length and other parameters through the man-machine interface. At the same time, it can accurately set the main draft multiple and dynamic closed-loop monitoring.
Enter the "System Menu" and select "Parameter Setting", and enter the basic "Parameter Setting" screen after entering the password. According to the process, set the bar speed, low speed speed, fixed length of the barrel, low speed length, suction delay and speed ratio. The delivery speed is usually 200 m / min ～ 500 m / min, the low speed is 100 m / min ～ 200 m / min, the fixed length of the can can be set according to the size of the can. The low speed length is generally 50 m to 200 m, so that it is appropriate to raise the speed after the yarn is in contact with the upper coil. The suction delay time is set from 3 s to 10 s. The speed ratio is set to 0.8 ～ 1.2, usually set to 1.0. This is because the speed is adjusted by frequency conversion. When the power frequency fluctuates, the actual output speed is inconsistent with the set speed. By adjusting the speed ratio, the speed set value can be adjusted The values are consistent.
In the "Design Rear Area Draft C" item of the touch screen, select "Rear Area Draft Synchronous Pulley", the machine will automatically calculate the rear area draft multiple. At the same time, when manually changing the synchronous pulley, the number of teeth should be consistent with the setting of the touch screen. The machine is equipped with 13 gears of different specifications, corresponding to the draft multiple of the rear zone from 1.1 times to 2.04 times.
After the setting is completed, after checking that the sliver weight and sliver meet the requirements, be sure to select “Join” on the “Closed Loop Control” item on the touch screen. In this way, the draft multiple between one roller and four rollers is under monitoring. When the stretch multiple exceeds 0.01 times of the design draft multiple, the machine will stop in time to ensure the quality stability of the sliver produced under abnormal conditions such as unstable voltage. Finally, select "closed" in the "big hood switch" item to ensure the safety of the car after driving.
