Measures to increase the yarn retention rate of spun yarn
"How to shorten the downtime of doffing and reduce the rate of doffing is the key to using a good spinning machine. We have achieved a high rate of doffing by properly adjusting the doffing process parameters and correctly executing the doffing operation procedure."
F1520 spinning car In order to ensure the rate of yarn retention, there is a function to solve the "little braid" in the doffing motion program. Before the main unit starts, the ring plate rises to the middle yarn position (the middle position of the bobbin, the specific position can be set). When the main unit starts, the ring plate quickly drops to release the small braid. The company's leading varieties of pure cotton 18.5 tex and 14.8 tex yarns have fewer doff ends, so the doff retention rate is higher, with an average of more than 98%.
We mainly take the following measures to improve the doff retention rate
Select the appropriate traveller, adjust the distance of the traveller cleaner to prevent or reduce the traveller hanging. Adjust the number of loops of the waste silk reel to prevent the excessive movement of the thread, which prevents the normal movement of the traveler and prevents the "small braid" from deteriorating and causing broken ends. The number of turns of the waste silk reel can be adjusted by the following parameters: spindle off-spindle braking time (3 seconds); ring plate drop-spindle off time (0 ~ 0.5 seconds); doffing spindle speed (5500 ~ 6500 rpm) ); The falling speed of the doffing ring plate; when the above four combined adjustments cannot achieve the ideal number of loops, check whether the electromagnetic brake system is adjusted well. The waste silk reel should be cleaned once a week, and for the varieties with thicker yarn count, the cleaning frequency can be increased according to the waste silk.
Set the proper middle yarn position and spinning spindle speed, to ensure that the air ring does not touch the spun yarn tube head or the yarn separation plate, and the distance between the leaf plate and the spun yarn tube should be kept appropriate. The doffing time of the automatic doffing system is about 260 seconds, and the head retention rate is higher than that of manual or manual first and then automatic head retention. Therefore, the automatic doffing system should be used instead of manual. The doffer should check the situation of spindle winding during doffing, and find that the spindle winding should be cleaned in time, which can prevent the spindle spinning from hindering the movement of the traveller and causing "small braids" to break.
Check whether the blower fan works well every day. To prevent the accumulation of flowers caused by the poor function of the blower fan, the occurrence of yarn defects and the accumulation of flowers on the convex disk, which can cause the convex disk to not move or be misaligned, affecting the gripping tube and normal doffing. The spun yarn belly is set to be cleaned by one person every shift to prevent the spun yarn from breaking off due to the floating flower on the belly. The grippers, bobbins and machine parts should be picked up in time to prevent the air frame rocker arm from reaching the top and causing the air frame to be misaligned, affecting the yarn fall. The convex disk track is cleaned once every 15 days with the trolley, to prevent the convex disk track from accumulating flowers, causing the convex disk to be misaligned and affecting the doffing. The doffing air frame is checked and leveled once every 15 days with the wiper to prevent the position of the air frame from being incorrect and affecting the normal doffing. Photoelectric inspection and cleaning of all parts in time to prevent the photoelectric failure from affecting the normal doffing. Spinning bobbins should be picked regularly to remove unqualified bobbins.
F1520 spun yarn doffing has two forms: automatic and manual. For the first time to use the long car, the equipment manufacturer will recommend the manual first and then the automatic method for safety reasons, that is, during normal production, the doffing knob is set to the manual position, and the doffing warning lamp flashes, and the doffer checks the car. If there is any abnormality, then turn the doffing knob to the automatic position to start the automatic operation procedure. The advantage of this is that it can prevent accidents caused by negligence of equipment and personnel. The disadvantage is that the doffing knob hits the manual. The servo motor is always energized, which will seriously shorten the life of the servo motor.
Long carts use aluminum casing spindles, all equipped with brake spindles. The aluminum sleeve spindle is equipped with a thin-arm spun yarn tube. The tight cooperation between the spun yarn tube and the spindle is mainly achieved by the three elastic shells (also called "cat's eyes") on the upper part of the spindle. When the spindle is running, the centrifugal force will cause the "cat's eye" to bear against the inner wall of the spinning tube to achieve a tight fit between the tube and the spindle. Some spun yarn blockers are not used to using the spindle brake, and some blockers suspect that using the spindle brake connector is slow, and there may be the phenomenon of directly pulling the yarn connector without the brake spindle. This will cause the cat's eyes to fall off, and the inner arm of the bobbin will be damaged, which will damage the bobbin and affect the quality of the yarn, which is very harmful. Therefore, we must prevent this from happening. There is also a brake spindle that brakes on the spindle for a long time, which will cause the spindle to become hot, the brake spindle to burn out, the spindle belt to burn out, and even the spindle to burn out, so this kind of bad operation should also be prevented. It should also try to avoid the simultaneous doffing of adjacent machines to ensure safety.
When the variety is changed, the draft gear needs to be modified at the front and rear, and it must be checked carefully, otherwise it will produce wrong support. When sampling raw spinning yarn, both the front and the rear must be taken to prevent errors. When the F1520 spun yarn doffing system is doffed, the fender is automatically turned up. It is necessary to prevent the wiping board from remaining on the fender when the fender is turned up, causing damage to the machine. The F1520 spinning car is equipped with an electronic lifting system, and the electrical is more complicated, and there are many servo motors. Therefore, when the equipment is installed, the power distribution system must have a harmonic processing device to prevent harmonic interference from causing unstable operation of the equipment and poor tube forming. When the spinning car is wired, the power line and the data signal line are required to be separated, which can prevent equipment malfunction caused by the interference of the data signal line.