A presentation on the technology of thread and seams, including thread and needle types, sizing conventions, seam and stitch types, and trouble shooting.
3. Thread size is determined the same way that yarn size is determined for
textiles. While there are different systems, they are all based on weight
and length specifications, and not by diameter as might be assumed.
METRIC TICKET (Nm)
# of 1,000 metre lengths in 1,000 grams
COTTON COUNT (Ne)
# of 840 yard hanks in 1 pound
TEX
grams per 10,000 metres
DENIER
grams per 9,000 metres
6. COTTON THREAD
Generally provides good sewing performance but strength and abrasion
resistance is inferior to synthetic threads of equal thickness
Mostly used for piece-dye items
Shrinkage may cause puckering after wash/dye
Can be mercerized reduces shrinkage, increases strength and luster,
improves dye up-take
8. SPUN POLYESTER THREAD
Made with staple polyester fibers. Provides good sewing
performance, good dimensional stability and good stitch locking
properties due to the fibrous surface.
Resistant to sunlight and chemicals
Stronger than cotton, including 4X better abrasion resistance
Ideal for light to medium weight fabrics
9. CORESPUN POLYESTER THREAD
Made by spinning staple polyester or cotton fibers around a continuous
filament polyester core. Provides enhanced strength and elongation while
maintaining stitch locking ability and can be run at higher speeds without
breakages.
Higher machine speeds mean an increase in productivity by up to 21%
Best thread for heavy fabrics, like denim and outerwear
More consistent sewing quality due to better loop formation and
resistance to damage
Most expensive general purpose sewing thread
10. TEXTURED FILAMENT THREAD
Continuous filaments of polyester or nylon are entangled by various
methods to create softness and bulk. Ideal for overlocking and the looper
of coverseams, these threads provide excellent coverage for raw edges
Most economical thread
Softness makes it ideal for lopping threads that sit close to the skin
Excellent elasticity for stretch fabric applications
Often found in intimates, baby clothes, and athletic wear
11. OTHER THREAD TYPES
Mono-filament Invisible Thread
Embroidery Thread
Elastic Thread
Specialty Lurex, Indigo
Locked Filament Thread
Glow in the Dark
12. LUBRICATION
Regardless of construction, all threads are finished with a lubricating
coating. This facilitates the passage of the thread through the machine and
needles, reducing friction and heat that can cause damage.
LIFE SPAN
Under optimal conditions, thread will last about 18 months before the
lubricants start to break down and thread quality starts to deteriorate.
Unsurprisingly, most factories do not store thread in optimal conditions
and so this period is usually much shorter.
15. Most sewing is done with rounded-point
needles. Actual cutting points are only
used for leather and similar fabrics. Set
Points are normal, lightly rounded points
used for wovens, while knits demand
more rounded needles, referred to as ball points
Different levels of roundness are identified with letter markers
16. R = Normal round
for light woven fabrics
SPI = Acute round
For densely woven fabrics
SES = Light Ball
Fine to medium knits, fine denim, medium to heavy wovens
SUK = Medium Ball
Stonewashed denims, corsetry
SKF = Heavy Ball
Fine elastic materials, coarse knits
SKL = Special Ball
Medium to coarse elastic materials, coarse knits, lycra
17. The fabric and end use will determine the thread size and type, and needle
type that you will use. The chosen thread will determine the needle size.
There will be a range of possible thread sizes and types that can be used
with any given fabric, depending on the application.
18. Seam Types
Stitch Types
Applications
What makes a good seam
25. 301 - LOCKSTITCH
Basic 1-needle straight stitch
Uses least amount of thread
Tightest and most secure stitch
High abrasion resistance due to low profile on the fabric
No stretch
26. 304 - ZIGZAG
1-needle zigzag lockstitch
Can stretch, and can provide edge coverage
Used to apply lace or appliques
Used for bar tacks and button holes
27. 101 - CHAINSTITCH
Formed using 1 thread only no bobbin or looper
On its own it is only suitable as a basting stitch
Blind hemming is a variation of this stitch
28. 401 - CHAINSTITCH
Formed using 2 threads needle and looper
Appears the same as 401, but is much more secure and
durable
Ability to stretch
Excellent for setting elastic
Frequently used for topstitching and for lapped seams on
high-wear garments like denim
Less thread passes through the fabric than on a
lockstitch, which can reduce seam pucker
404 Zigzag chainstitch
29. 406 and 407 COVER STITCH
406 uses 3 threads, 407 uses 4
Excellent stretch. 407 has the most stretch
Excellent strength
Looper stitches are more efficient because you dont have
to change a bobbin
Less thread passes through the fabric than on a lockstitch,
which can reduce seam pucker
Increased seam bulk
Increased cost
30. 503 2-THREAD OVEREDGE SERGE
Formed using 1 needle and 1 looper thread
No structural strength only suitable for coverage of inner
seam allowances
504 3-THREAD OVEREDGE SERGE (OVERLOCK)
Formed using 1 needle thread, 1 looper thread, and 1 cover
thread
Most common for overlocking, and often used for sewing
seams on knit fabric
31. 512 and 514 MOCK SAFETY STITCH
Formed using 2 needle threads, 1 looper, and 1 cover
thread
Common for seaming knits, and can be used for wovens as
well
Only 514 should be used on knits as it has better stretch
32. 515, 516 SAFETY STITCHES
A combination of an overedge stitch with a 401 chainstitch
515: 4-thread safety uses a 503 overedge serge
516: 5-thread safety uses a 504 overlock stitch
33. FLATLOCK 600 CLASS
Formed using 2 4 needle threads plus 1 looper thread and
1 cover thread
Fabric edges butt together but do not overlap
Highly elastic seams with very low profile for maximum
comfort
Efficient to sew
Very high thread consumption
Common for performance and scuba wear
39. SEAM PUCKER
Bad tension
Bad feed
Fabric-Thread instability
Uneven shrinkage during finishing
Thread-bloat from washing
Structural jamming/Inherent pucker
Tight weaving does not have enough room between yarns
for thread
Sewing caused yarns to be pushed out of place
43. SKIPPED STITCHES
Bad tension
Machine timing is off
Bobbin hook or looper is not entering needle thread loop
at correct time
Incorrect needle choice
The wrong needle can cause problems in creating the
needle thread loop
Damaged needle
If the needle is bent, or is striking the throat plate, it may
not create the loop in the right place for the hook to
catch
45. NEEDLE THREAD BREAKAGE
Tight tension
Trapping at package base
Snarling before tension disc
Poor needle choice
If eye is too small, there will be increased friction
Excessive heat
Poor quality thread
51. SEAM SLIPPAGE
Problem is with the fabric not the stitch
Low yarn count, and continuous filament yarns that dont grip
each other well are to blame
Very minimal improvement can be achieved through
increasing seam allowance, adding topstitching, or changing
to a lapped felled seam
When possible, seams can be fused
Best option Change fabric
#8: COTTON THREADCHANGES DURING MERCERIZING PROCESSA. Fiber level1.Swelling2.Cross sectional morphology changes from beam shape to round shape.3.Shrinkage along with longitudinal direction.B. Molecular level1.Hydrogen bond readjustment2.Orientation (parallelization) of molecular chains in amorphous region along the direction of fiber length.3.Orientation of the crystallinity in the direction of the fiber length.4.Increased crystallinity