1, jump needle
(1) occasional jumping needles. Reason 1: machine needle hairiness, machine needle bending, machine needle groove is not smooth or improper selection. Troubleshooting: replace the appropriate needle. Reason two: machine needle installation skew, machine needle and rotating shuttle distance is not appropriate. Troubleshooting: adjust the distance between the needle and the tip of the rotating shuttle to make it within the standard range. Reason 3: the thickness of the thread is not uniform, the twist is not uniform, affect the formation of the thread ring. Exclusion: select quality sewing thread according to standard. Reason four; Wrong height of needle bar. Rule out: adjust the height of the needle. Reason 5: wear of rotating nozzle. Troubleshooting: grinding, polishing. Reason 6: pressure foot pressure too small, sewing thread jitter, unable to pressure line, impact ring. Rule out: increase pressure on the foot. Reason 7: pressure foot slot is too wide, when machine needling cloth exits, fabric rising affects the formation of line ring. In this case, the impact of thin material is the greatest, excluding method: according to the fabric to move the presser foot left, right, can be filled with a wide groove solder. Reason 8: the stitching spring is too low, the matching of fabric, needle and thread is improper. Elimination method: adjust the height of the spring. Reason 9: the hole of needle plate is too big, the fabric drops randomly when sewing thin fabric, and the formation of delay line ring. Elimination methods; Replace the needle plate. Reason 10: the positioning of the rotating shuttle is not standard. The distance between the tip and the needle is too far. Rule out: adjust accordingly.
(2) continuous jumper. Reason 1: when high speed sewing, machine needle and thread fever, so that the seam softens, difficult to form an ideal thread ring. Exclusion method: when using chemical fiber thread to sew at high speed, it can be used to add silicon oil at the crossing of the surface thread to cool, or use compressed air to cool the machine needle by blowing. Reason 2: the quality of the upper thread is too large, and the sewing thread is subjected to a large stretching effect, and the thread ring is not easy to form. Rule out: reduce the tension of the thread so that the thread will be stretched as little as possible under the material. Reason 3: sewing different thick and thin transition part, or sewing different soft and hard, elastic fabric caused by jump needle. Elimination method: according to the thickness of the fabric and its properties, adjust the size of all parts of the machine in a timely manner.
2. Section (upper) line
The locked-type line traces are interwoven from the upper line and lower line, so they can be divided into two types: section line and fault line. There are many parts passing through the surface (upper) line, and the reasons are complicated.
(1) the flat seam machine will break when it is put into operation.
Reason 1: machine needle is installed in reverse or pin handle is not top in place. Troubleshooting: check the needle and needle handle. Reason 2: the upper wheel is reversed. Elimination methods; Check the rotation direction of upper wheel. Reason 3: the pressure of the online tensioner is too high. Exclusion method: check whether the tensioner is normal. Reason 4: the order of online putting and guiding is not required. Troubleshooting: thread the lead as required. Reason 5: assembly did not meet the requirements. Troubleshooting: check the gap between the locating hook and the rotating shuttle, between the needle and the nozzle.
(2) cross section line in normal sewing process
Reason 1: machine needle or sew to cooperate inappropriately. Exclusion method: select needle and thread suitable for fabric. Reason 2: the quality of sewing thread is not good. Elimination methods; Choose high strength sewing thread. Reason 3: pinhole edge is not smooth or needle groove has burr. Rule out: polish. Reason 4: there are burrs, bruises or insufficient finish on the tip of the hook. Elimination methods: triangular oil stone, polishing paste, gap polishing, etc. Reason 5: the take-up spring is too tight, too high, not flexible or uneven pressure. Elimination method: adjust the height of the stitching spring and adjust the pressure of the clipper properly. Reason 6: the stitching spring is too tight and loses its elasticity. When the rotating shuttle is running, the shuttle door turns up and the sewing thread is blocked. Exclusion: elongate or replace the bottom spring of the door. Cause 7: needle overheating, suture is fused. Elimination method: adopt "needle heat countermeasure". Cause 8: the surface of the wire through the wire holes part of the hair, sewing thread when the movement blocked. Method of elimination: grinding with sand cloth bar, and then applying with line polishing paste to make it smooth or polished.
(3) back seam broken
Reason 1: feeding cloth teeth and machine needle improper coordination. Troubleshooting: adjust the feeding teeth and needle according to the standard. Reason 2: the cloth is smooth when coming online. Exclusion method: the part of the surface line passing through the backseam is polished.
3. Breaking the bottom line (lower line)
Reason 1: there is an acute Angle on the edge of the feeding tooth. Elimination: wipe or polish with gauze. Reason 2: the placement of the cloth feeding teeth is too low. When the cloth feeding teeth are in contact with the bottom of the cloth feeding teeth, the thread will be worn out. Exclusion: adjust the height and height of the feeding teeth. Reason 3: because of wear, the thread-needle holes are punctured. Rule out: replace. Reason 4: the bobbin winding is too full. Exclusion method: the bobbin must not be higher than the bottom line. Reason 5: the edge of the spiral bobbin hair, wipe the bottom line. Elimination: repair and grinding the edge of the rotating spindle. Reason 6: the fit precision of the bobbin and the bobbin is poor, and periodic rebinding occurs. Exclusion method: check the bobbin and bobbin, and observe whether the tension is even when the wire is out. Reason 7: quality problem of rotating shuttle. Troubleshooting: check the outlet groove located on the upper left side of the rotating frame.
Float the bottom or surface line
Reason 1: the bottom line, surface line tension is too large or too small. Troubleshooting: adjust the clamp nut and adjust the screw. Cause 2: improper coordination between feeding teeth and movement of needle and wire rod. Exclusion method: adjust the position of the needle mechanism and the feed tooth mechanism.
5. Towel-like floatation line
Reason 1: the sharp beak and flat surface of rotating shuttle are rough and scratched, which hinders the online tightening. Elimination method: grinding each passing part of rotating shuttle. Reason 2: the sewing thread is wound on the locating hook flange, which makes the upper and lower threads not free. Troubleshooting: remove stitching around the positioning hook.
6. When floating, do not float
Reason 1: the match between the bobbin and the bobbin sleeve is not allowed. Exclusion method: select suitable bobbin and bobbin sleeve. Reason two: pressure toe board under the outlet groove too shallow too short, pressure line. Elimination method: use yarn cloth to draw deep, elongate and press the toe board under the cutter out groove
7, broken needle
(1) occasionally broken needle
Reason 1: machine needle bending, needle point hair or fixed needle screw not tight. Rule out: replace or tighten. Reason 2: when the thickness of the uneven garment piece is stitched too fast, the machine needle migration, resulting in broken needle. Rule out: slow down properly. Reason 3: the operator's movements are not coordinated, and the material of push-pull sewing is too complex, which makes the machine needle shift and collide with the needle plate. Rule out: use correctly and coordinate your actions.
(2) continuous broken needle
Reason 1: the foot fixation screw is not tightened. Troubleshooting: check the positioning of press-foot screws and press-foot screws. Reason 2: the needle plate is narrow, and the error of concentricity between pinhole and machine needle is too large. Exclusion method: to re-select the needle plate or adjust the needle plate screw until the error of coaxiality between the machine needle and the needle plate hole is within 0.2mm. Reason 3: machine needle and feed cloth tooth cooperate badly, do not synchronize. Elimination method: adjust the motion coordination between the needle and the feed tooth. Reason 4: the machine needle travel is not correct, and the movement with other organs improper coordination. Troubleshooting: check whether the needle stroke crank screw is fastened in the groove.
8. Poor cloth delivery, stagnant cloth.
Reason 1: pressure of the foot. Rule out: reduce pressure on the presser foot. Reason 2: the feeding teeth are tilted. Exclusion: correct and correct the feeding tooth position. Reason 3: send cloth tooth position too low. Troubleshooting: adjust the distance of the feeding tooth to expose the needle plate to make its position correct. Reason 4: the pressure of the foot is too small or the bottom of the foot is not smooth and clean. Troubleshooting: properly increase the pressure or repair the pressure foot bottom. Reason 5: lower knife installed too high, or cutting edge knife too blunt. Troubleshooting: after grinding installation in place. Reason 6: feeding machine parts wear seriously, with loose. Rule out: repair and adjust.
9. Fabric wrinkling
Reason 1: the motion speed of feeding cloth teeth is greater than that of needle bar. Rule out: adjust speed to standard or slightly slower than needle bar. Reason 2: the feeding teeth are not accurate. Elimination method: adjust the position of the feeding tooth or to the state of high before and low after, so as to reduce the contact surface between the bottom of the foot and the feeding tooth and prevent the fabric from wrinkling. Reason 3: send cloth tooth to rise above needle plate overmuch. Exclusion method: adjust the distance position of the cloth feeding tooth to expose the needle plate. When sewing thin fabric, the cloth feeding tooth is 0.6mm higher than the needle plate. Reason 4: the selected needle is too thick. Rule out: replace the needle.
10. Poor line mark.
(1) uneven track length
Reason 1: the rotating speed of sewing machine is high. Exclusion: reduce the speed of rotation within the permitted range. Reason 2: weak pressure of presser foot. Rule out: increase the pressure appropriately. Reason 3: upper tension is big, or lower tension is small. Elimination: reduce or increase tension.
(2) the trace is skewed
Reason 1: the feeding teeth are not parallel to the plane of the presser foot. Elimination: grinding or replacement. Reason 2: needle bar wire hook and needle bar wire sleeve are out of position. Troubleshooting: install wire hook and wire sleeve.
11. Poor lubrication
Reason 1: the oil level of the oil pool is too low to exclude the method: add lubricating oil between the two lines as required. Reason 2: oil road blockage, oil screen blockage, oil absorption line short. Elimination: dredge, check and replace.
