Common sewing problem: Causes and Remedies
There can be many reasons behind
the problems that arise while sewing and knowing the cause of these problems and a solution for each
particular cause is essential. These problems can be minimised by avoiding
errors during handing of materials / machines and by following the
right working methods.
Some common sewing problems are;
- Needle thread breakage
- Bobbin or looper thread breakage
- Thread fusing when the machine stops
- Skipped stitches
- Imbalanced / variable stitching
- Staggered stitching
- Variable stitch density
- Seam pucker
Needle Thread Breakage:
Cause
|
Remedy
|
Misaligned
off winding from thread package
|
Ensure
that the overhead guide is directly above cop stand pin, at 2½ times the
height of the thread package. Use a foam pad to prevent package tilting
|
Trapping at package base
|
Reduce
the thread stand height to prevent vibration and spillage. Use a foam pad to
prevent trapping after spillage
|
Thread trapped at thread guide
|
Can occur after thread breaks.
Rethread correctly
|
Snarling before tension disc
|
Increase
the wraps on pre-tension thread guides and reduce disc tension. Ensure discs
are smooth
|
Excessive
tension
|
Use a stronger thread or adjust
tension
|
Broken check spring
|
Replace and adjust
|
Sharp
edges on throat plate, hook point,
needle guard, bobbin case, needle groove or eye
|
Polish
rough edges and replace if necessary. Replace the needle being used with a
higher quality needle
|
Thread fraying at needle
|
Use
finer thread or coarser needle, as appropriate
|
Excessive
needle heat; groove or eye blocked with melted fabric
|
Improve
the fabric finish. Change to a better needle, style and finish. Apply needle
lubricant via thread. Use a needle cooler
|
Hook overheating
|
Ensure
adequate oil supply. Check the needle to hook clearance
|
Poor quality thread
|
Change to a correctly finished thread
of better quality
|
Bobbin or Looper Thread Breakage:
Cause
|
Remedy
|
Badly wound thread on the bobbin
|
Adjust bobbin winder alignment. Use
pre-wound bobbins
|
Tension too tight or bobbin
over-running
|
Adjust
bobbin case tension. Insert a washer or a spring to prevent over-running
|
Sharp
edges on bobbin case or spring or looper eyelet
|
Polish edges and correct surfaces
|
Bobbin case not fitting correctly
|
Check the size / type of bobbin for
flange distortion
|
Thread Fusing when the Machine Stops:
Cause
|
Remedy
|
Poorly finished or incorrect thread
|
Use better quality thread
|
Densely
woven fabric that is poorly or harshly finished
|
Improve
fabric finish. Change to more suitable needles. Apply needle coolants
|
Damaged
or overheated needle after thread breakage
|
Change the needle.
|
Skipped Stitches:
Cause
|
Remedy
|
Hook,
looper or needle failing to enter thread loops at the correct time
|
Check
machine clearances and timings. Check if the needle is inserted and aligned
correctly. Use a needle with a deeper scarf
|
Thread
loop failure caused by incorrect needle size / style for thread size / type
|
Change needle size / style
|
Thread
loop failure due to incorrect setting of thread control mechanism causing
thread loop starvation
|
Reset
to standard and check loop formation with a strobe
|
Flagging
of fabric due to poor presser foot control or too large a throat plate hole
|
Re-adjust
the presser foot pressure. Change the throat plate to match the needle
|
Needle deflections or bent needle
|
Use
a reinforced needle, reset the needle guard and replace the needle
|
Incorrect
sewing tension in the needle or under threads
|
Re-adjust the tensions
|
Poor thread loop formation
|
Check
with a strobe. Change to superior spun polyester or filament based corespun
threads
|
Imbalanced / Variable Stitching:
Cause
|
Remedy
|
Incorrect sewing tensions
|
Check for snarling, adjust thread
tensions
|
Incorrect threading
|
Rethread machine
|
Needle
thread snagging on bobbin case or positioning finger
|
Polish
bobbin case surfaces. Reset positioning finger and opening finger
|
Variable
tension due to poor thread lubrication
|
Switch
to superior quality threads
|
Staggered Stitching:
Cause
|
Remedy
|
Needle vibration or deflection
|
Increase
needle size or change to a reinforced
or tapered needle
|
Incorrect or blunt needle point
|
Change the needle
|
Incorrect needle-to-thread size
relationship
|
Change needle or thread size as
appropriate
|
Feed dog sway
|
Tighten the feed dog
|
Poor fabric control, presser foot
bounce
|
Reset the presser foot. Change the
feed mechanism
|
Variable Stitch Density:
Cause
|
Remedy
|
Poor fabric feed control
|
Increase
the presser foot pressure. Change to a more positive feed mechanism
|
Seam Pucker:
Cause
|
Remedy
|
Variable differential fabric feed
|
Improve
the fabric feed mechanism. Replace worn out feed dogs. Reduce the maximum
sewing speed
|
High thread tension
|
Keep
the bobbin tension as low as possible and set the needle thread tension
accordingly
|
Incorrect thread balance
|
Ensure
proper balance between the top and bottom thread
|
Improper thread type
|
Use
threads with controlled elongation. Properly maintain tension guides
|