1. Yarn point entanglement or bent weft breakage
At the tip of the weft yarn on the right side of the fabric, there is a slight tangle or bend, resulting in a broken weft, resulting in a stop.
Cause
(1) The edge yarn, skein yarn, and false edge yarn on the right side of the selvage are loose, or warp yarn defects, flying flowers, etc. cause the opening to be unclear.
(2) The pressure of the main nozzle is too high, or the installation is not standard.
(3) The air injection time of the main nozzle and the action time of the electromagnetic needle are improperly coordinated.
(4) The height and position of the electromagnetic needle are not standard. the
(5) Compressed air pipeline leaks.
(6) The pressure of the auxiliary nozzle is too low, and the height and angle are not suitable.
(7) The left scissors are not sharp.
(8) The left selvedge warp is loose.
(9) The reed surface is not clean, with flying flowers and sundries attached.
(10) The solenoid valve is not working properly.
Elimination method
(1) Increase the warp tension or remove yarn defects and flying flowers. the
(2) Reduce the pressure of the main nozzle or adjust the pressure position of the main nozzle. the
(3) Advance or delay the development time of the electromagnetic needle, and advance or delay the air injection time of the main nozzle to an appropriate time. the
(4) Check and adjust the electromagnetic needle according to the timing standard and installation specification. the
(5) Check the compressed air pipeline regularly. the
(6) Increase the pressure of the auxiliary nozzle, and check its height and angle (according to the weft type). the
(7) The left scissor blade must always be kept sharp. the
(8) The threading method of the heald warp yarn in the heddle and the reed must be correct. the
(9) Always keep the reed surface of the profiled reed clean. the
(10) Press the test button on the control panel, if the solenoid valve stops working, check the solenoid valve, if the solenoid valve works, but does not work during continuous operation; then check the encoder.
2. Weft bending type weft breaking
The U-shaped bending of the weft yarn is caused by insufficient weft insertion, poor shedding and delayed arrival of the weft yarn. Cause the loom to stop or form double thinning weft defects.
Cause
(1) The air injection time of the main nozzle and the action time of the electromagnetic needle are improper. the
(2) When cutting, the weft yarn comes out of the electromagnetic needle. the
(3) Compressed air pipeline leaks. the
(4) The auxiliary nozzle pressure is too low. the
(5) The opening of the loom is faulty, and the warp yarn has hairiness, large knots, flying flowers and other yarn defects. the
(6) The amount of opening is too small or the opening time is not standard. the
(7) The warp hits the tip of the auxiliary nozzle. the
(8) Warp tension is too small. the
(9) The position of the main nozzle is wrong.
Elimination method
(1) Advance or delay the opening time of the electromagnetic needle, and advance or delay the air injection time of the main nozzle. the
(2) Adjust the action time of the left scissors and yarn guide to reduce the cutting resistance; or properly increase the cutting and blowing pressure. the
(3) Check mechanical valves and air pipes that are bent or leaking, and adjust or replace them. the
(4) Properly increase the pressure of the auxiliary nozzle. the
(5) Strictly grasp the requirement that the warp joints are less than 3mm, and remove warp defects such as large joints, feather yarn and flying flower attachment. the
(6) Increase the opening amount, check and adjust the opening time.
(7) Move the auxiliary nozzle laterally by 0.1~0.2 mm, and check the smoothness of the auxiliary nozzle head. the
(8) Measure and increase warp tension. the
(9) Correctly adjust its position with the main nozzle gauge.
3. The weft yarn and the warp yarn on the left side of the selvage are twisted to catch the broken weft
The opening time is improperly coordinated with the flight time of the weft yarn. The weft yarn is caught by the warp yarn on the left side of the cloth, and the loom stops or forms a weft weaving defect.
Cause
(1) The timing of the electromagnetic needle, the spraying time of the main nozzle and the opening time are improperly coordinated. the
(2) Slack side yarn on the left side of the selvage or loose warp yarn on other sides. the
(3) The main nozzle is not installed correctly.
Elimination method
(1) Delay the time when the weft yarn leaves the electromagnetic needle and advance the opening time. the
(2) Correct the tension of skein yarn and false edge yarn, or correct the opening time. the
(3) Make correct adjustments with the main nozzle gauge.
4. Weft and warp entangled weft breaking
The weft yarn is twisted with the middle warp yarn to form an S-shaped bend. The main reason is that the tension of the warp yarns is uneven or the warp yarns have yarn defects, which cause shedding failures, which cause the loom to stop or form double weft weft defects.
Cause
(1) The warp yarn tension is too small or the sheet yarn tension is seriously uneven. the
(2) Warp yarn defects (feathers, large knots, neps, cotton balls, fly attachment, etc.). the
(3) The opening is too small. the
(4) The left scissors cut the yarn poorly.
Elimination method
(1) Measure and increase warp tension, and eliminate factors such as local uneven tension. the
(2) Remove the yarn defects and the joint tail yarn should not exceed 3mm. the
(3) Properly increase the opening height. the
(4) Adjust the action time of the left scissors and the amount of blade engagement to make the scissors sharp.
5. Weft breakage due to uneven weft insertion length
The weft yarns introduced into the weaving fell are of different lengths, and the phenomenon of long and short wefts appears. It is mainly caused by unstable length measurement and weft storage and insufficient weft insertion force.
Cause
(1) The pre-winding amount of weft yarn is insufficient. the
(2) The closing time of the electromagnetic needle is too early. the
(3) The main nozzle is blocked by cotton yarn, and the pressure is too low. the
(4) The winding shape of the weft yarn is bad or the winding hardness is not appropriate. The quality of weft yarn is poor, and there are many yarn defects, such as joints, flying cotton lint, and attachment of returned silk.
Elimination method
(1) Remove flying flowers and check the jet air flow. the
(2) Rewind the yarn correctly. the
(3) Adjust the pressure according to the prescribed method and standard. the
(4) Appropriately increase the pre-winding volume of the weft feeder. the
(5) Delay the closing time of the electromagnetic needle. the
(6) Increase the main nozzle pressure. the
(7) Remove lint from clogged parts. the
(8) Change the form of weft yarn winding, improve the hardness of the weft cylinder, greatly improve the quality of weft yarn, and reduce yarn defects.
6. Yarn tip blowing type weft breaking
It is mainly caused by too high jet pressure of weft insertion or weak weft yarn.
Cause
(1) The pressure of the main nozzle is too high. the
(2) The shear blowing is too strong. the
(3) The weft yarn is uneven, and the yarn body has many details.
Elimination method
(1) Reduce the main nozzle pressure. the
(2) Reduce the shear blowing pressure. the
(3) Replace the weft yarn and take measures to improve the quality of the weft yarn.
7. Weft breakage by blowing in the middle of the weft yarn
The weft insertion force is too strong, the action time is too long or the details of the weft yarn are blown off within the width of the cloth, causing the loom to stop or form double-dense defects.
Cause
(1) The weft release angle is too small. the
(2) The pressure of the main and auxiliary nozzles is too high, the opening (start and end time) is too large, and the injection angle of the auxiliary nozzles is too large. the
(3) The weft yarn has weak yarns with details.
Elimination method
(1) Properly increase the release angle.
(2) Reduce the pressure of the main and auxiliary nozzles, check the weft yarn flight curve, reduce the opening (start and end time), avoid excessive air injection, and reduce the injection angle of the auxiliary nozzles. the
(3) Change the weft yarn to improve the quality of the weft yarn. the
8. Shearing error type weft break
Shearing error type weft breakage is caused by the main nozzle side weft yarn not being cut before weft beating after weft insertion.
Cause
(1) The blades of the scissors are sharp and poorly meshed. the
(2) The installation position of the scissors is not good, and the cutting time is not standard. the
(3) The shear blowing pressure is too low. the
(4) The weft yarn arrives at the opposite side later.
Elimination method
(1) Grind the blade periodically and adjust the meshing. the
(2) Correct the position according to the scissors installation specifications, and adjust the time. the
(3) Appropriately reduce the cutting and blowing pressure. the
(4) Increase the pressure of the main and auxiliary nozzles and prolong the air injection time of the auxiliary nozzles.
9. Fault stop
The weft yarn reaches normal, but due to reasons such as abnormal weft yarn flight, skein edge yarn, weft edge yarn capture, electrical failure, etc., the signal of no weft yarn arrival is sent by mistake, resulting in shutdown.
Cause
(1) The weft yarn entering the weft-catching side yarn is abnormal. the
(2) The hemming yarn on the right side is loose. the
(3) The shape or position of the weft arrival probe is incorrect. the
(4) There is a problem with the cable of the weft probe, or the surface of the steel mouth reflection area of the probe is not clean. the
(5) The sensitivity of the weft probe is poor, and the detection board is faulty. the
(6) The gap between the weft probe and the reed is inappropriate. the
(7) Vibration of shaped reed teeth.
Elimination method
(1) Adjust the nozzle position, remove lint, and solve the problem of weft looseness. the
(2) Adjust the side yarn tension so that the side yarn reeding meets the specifications. the
(3) Adjust the angle of the last group of auxiliary nozzles, and keep the distance from the weft probe WWF1 at about 50mm. the
(4) Replace the faulty weft finder in time, and keep the probe and reed clean. the
(5) Check the sensitivity of the weft detector so that it does not shut down the machine empty. Check and replace the weft probe board at the same time. the
(6) Adjust the gap between the weft probe and the reed according to the installation specifications. the
(7) Stick a black tape on the reed, which can not only reduce the vibration of the reed teeth, but also prevent the diffusion of the jet air from the reed
Post time: May-15-2023
