Apparel Online Bangladesh Magazine July Issue 2018 | Page 47

Some of the
computerised
sewing machines
come with a feature
called ‘ply sensor’.
This feature can
sense the difference
between number
of plies through a
sensor and stop the
machine accurately.
A typical patch pocket having 4 sides of measurement
sewing floor. And unfortunately
the machine manufacturers keep
fooling around these features. A
typical patch pocket (as shown
in the figure) will have 4 sides of
measurement. The programmable
lockstitch machine can easily
program these four steps with
given SPI. For example suppose the
pocket side A-B is 5 inches, B-C is 3
inches, C-D is 3 inches, and D-E is 5
inches, at 12 SPI, A-B, length should
contain 60 stitches and similarly
36 stitches in next step and so
on. But in reality while creasing
the pocket, there may be minor
variations of length A-B between
pieces to pieces or between A-B
and D-E. Suppose the tolerance
is 1/8th inches (as such small
variation in length will not make
the pocket commercially visually
unacceptable). If in A-B length
of one pocket is 1/8th inch
smaller, then 60 stitches will
shoot off the corner and pivot
point will be outside the pocket.
If the pocket A-B measurement
is 1/8th inch longer, then pivot
point will not be exactly at the
corner and the look will be
unacceptable. These problems
arise because stitch programming
go by exact number of stitches
and cannot adjust one or two
stitches more or less due to slight
very useful and practical solution
for deskilling the patch pocket
attaching operation, the awareness
and popularity of these machines
are very less. Unfortunately
the machine manufacturers do
not promote these machines to
manufacturers correctly.
Another reason behind non-
popularity of ply-sensor
technology was frequent
malfunction of sensors in dusty
and lint-scattered surfaces. But
with more and more cleaner
factories coming up, the
technology is worth considering.
variation in measurement which is
commercially acceptable.
Step programming machine will
only work successfully where
pocket creasing is consistently
accurate to fraction of a millimetre
which is generally not possible even
using pocket creasing machine.
Although all the computerised
machines with step programming
facilities have an additional stitch
button, it is still inconvenient for the
operator and may ultimately take
longer time than using an ordinary
machine.
I can never attach patch pocket
using computerised sewing
machine
WRONG
Some of the computerised sewing
machines come with a feature
called ‘ply sensor’. This feature
can sense the difference between
number of plies through a sensor
and stop the machine accurately.
While attaching patch pocket, the
stitch is given on the edge of pocket
fold (three plies), while the body
of the fabric is only single ply. The
ply sensor can sense the difference
between single and three plies
and accurately stop at all corners;
the operator only has to pivot and
press the pedal to start sewing.
Although ply sensor technology is a
www.apparelresources.com | July 2018 | Apparel Online Bangladesh
47