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Problem-
Consumer dissatisfaction and returns of sewn products due to failures in
buttonsewing, buttonholes, and bartacks.
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Most
typical buttonsew machines in the industry are cycle machines that
have the capability of making 8, 16, or 32 stitches on two and four
hole flat buttons or shank buttons. The flat buttonsew clamp
mechanism comes standard on these machines. Most machines can be
converted over to sew shank buttons by changing the clamp and the
plate with support block.
Light Weight
Fabrics
2-hole flat or shank buttons attached to light weight fabrics are
usually sewn with 8 stitches. Usually 4-hole flat buttons attached to
light fabrics are sewn with 16 stitches. The thread generally used
is a T-21 or T-27 spun or T-24 corespun thread.
If the buttons have any sharp edges like metal buttons, we recommend
corespun threads.
Medium Weight
Fabrics
2-hole and 4-hole buttons attached to medium weight fabrics are
usually sewn with 16 stitches. We recommend using a corespun thread
for button attaching. Medium Wt. Fabrics = T-40 Perma Core®.
Heavy Weight
Fabrics
2-hole and 4-hole buttons are generally attached with 16 stitches. On
some extra heavy applications, 32 stitches (double cycle) are used for
attaching the button. We generally recommend using a corespun thread.
Heavy Wt. Fabrics = T-60, T-80 Perma Core®.
Note:
Most buttonsew failures are due to unraveling stitches and not thread
failure. If buttonsew failure is being caused by the stitch
unraveling and not breaking, we recommend using a lockstitch buttonsew
machine instead of a single-thread chainstitch buttonsew machine.
Make sure the same size bobbin thread is used as the needle thread.
Some Retailers have even specified a slightly different color bobbin
thread than needle thread so they know for sure the stitch was sewn
with a lockstitch. Lockstitch buttonsew will not unravel and is very
common on infants and childrenswear where you do not want any button
failures.
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Button Size and Buttonhole Length Chart |
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Button Size
(Diameter Measured in Ligne) |
Buttonhole length |
Buttonhole length |
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Ligne
12
14
15
16
18
19
20
22
24
27
28
30
32
34
36
40 |
mm
7.5
9.2
10.0
10.5
11.6
12.0
12.7
14.2
15.1
17.0
17.8
19.1
20.5
21.5
23.0
25.5 |
Inch
5/16”
3/8”
13/32”
5/8”
7/16”
15/32”
1/2"
9/16”
19/32”
21/32”
11/16”
3/4"
13/16”
27/32”
29/32”
1” |
Millimeters
9.0 to 9.4 mm
11.1 to 11.5 mm
12.0 to 12.5 mm
12.6 to 13.1 mm
13.9 to 14.5 mm
14.4 to 15.0 mm
15.2 to 15.9 mm
17.0 to 17.8 mm
18.2 to 18.9 mm
20.4 to 21.3 mm
21.4 to 22.3 mm
22.9 to 23.9 mm
24.2 to 25.3 mm
25.8 to 26.9 mm
27.6 to 28.8 mm
30.6 to 31.9 mm |
Inches
11/32” – 3/8”
7/16” – 15/32”
15/32” – 1/2"
1/2" – 17/32”
17/32” – 9/16”
9/16” – 19/32”
19/32” – 5/8”
21/32” - 11/16”
23/32” – 3/4"
13/16” – 27/32”
27/32” – 7/8”
29/32” – 15/16”
31/32 – 1”
1” – 1 1/32”
1 1/16 – 1 3/32”
1 3/32” – 1 1/8” |
As you can see from
the chart above,
the recommended length of
the buttonhole should be approximately 20 - 25% longer than the
diameter of the button. On some applications with a fusible
interlining, this dimension could be as low as 15% of the diameter of
the button. The length of the buttonhole is measured on the inside of
the buttonhole stitch from end to end. On very light weight, flimsy
fabrics, it might be desirable to use a smaller length of buttonhole
to minimize the ease at which the button will pull through.
On the
traditional buttonhole machines, in order to change the length of the
buttonhole, you have to change the cutting knife length, which will
require changing parts on the sewing machine. Because of this, your
contractor may not be able to sew your buttonholes to your exact
specifications without having to go out and buy new parts for their
machines. Some newer buttonhole machines are equipped with an
adjustable knife mechanism that does not require a knife change to
make different buttonhole lengths.
There are two types of cutting methods used on buttonhole machines used in the
industry:
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Cut- After
Buttonhole Machines:
These are by far the most common type of buttonhole machines in use
today. They sew the buttonhole first and then the knife comes down
and cuts the slit in the buttonhole. This buttonhole cutting method
is more common because it minimizes “flagging” that can cause
skipped stitches. It is important for the factory to properly
maintain the knife sharpness and proper settings.
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Cut - Before
Buttonhole Machines:These are not as common as the Cut-After Buttonhole machines. They
produce a better quality buttonhole due to the fact that they cut
the fabric first and then stitch over the edge of fabric giving you
a cleaner finish. However, these machines are more expensive and
require better technical skills to maintain. They are primarily
used on “best quality” shirts, pants, and outwear that are sewn with
a fusible interlining.
On eyelet buttonhole
applications, it is normally recommended to use a buttonhole gimp to
help maintain the integrity and shape of the buttonhole. Typically a
T-180 or T-210 polyester or cotton yarn is used for Gimp. A&E has two
products called T-180 Anecot® Gimp, which is a 100%
cotton buttonhole gimp. The other product is T-210 Anepoly™ Gimp,
which is a 100% spun polyester buttonhole gimp.
Bartacks are used to re-enforce seams and attach belt loops, straps,
etc. The most common bartack sewing machine used today is a
lockstitch bartacker that produces 28 stitches in the stitch cycle.
On very heavy weight fabrics and on demanding applications,
bartacking machines are used that produce 42 or 56 stitches in the
tack. The typical clamp on a bartack machine allows for a maximum
tack length of 3/4” (19.1mm) and a maximum width of approximately
5/32” (4mm).
Most
manufacturers will use the same size thread for bartacking as they do
for seaming. However, the maximum size thread that can generally be
sewn on a bartacker without sewing issues is a T-80 thread size.
Besides causing excessive thread breakage, larger thread size may
exceed the capacity of the hook causing poor stitch balance and
fraying thread.
You
can usually increase the seam strength at bartacks by increasing the
width of the bartack so the stitches catch more yarns in the fabric
minimizing fabric failure at the tack.
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