Brother sewing machine showroom in chennai - VS Enterprises
In this article two methods are used to measure the temperature
of needle eye during the high speed of sewing and the results are
compared for calculating the precision in the measurement,Needle
heatup is a big issue for apparel industry especially for automobile
industry seat covers where a lot of synthetic materials are used
which get damaged by needle heat at high speed of sewing
machine,in this article thermocamera and thermocouple are used to
calculate the precise temperature of needle eye and then 100%
polyester 35x3 Tex thread is taken for sewing,the lockstitch sewing
machine is run at 1000rpm,2000rpm and 3000rpm respectively and
the both methods are used to obtain the accurate needle
temperature and finally thread tensile properties the article is very
helpful in predicting the exact temperature of needle in lock stitch
machine at different stages of sewing process.
Keywords—needle eye heat,needle temperature of sewing
machine
Introduction: Industrial sewing is one of the most commonly
used manufacturing operations. Its applications can be found
in the manufacturing of garments, shoes, furniture, and
automobiles, just to name a few. Every day, millions of
products, ranging from shirts to automotive airbags, are sewn.
Hence, even a small improvement may result in significant
corporate benefits. In heavy industry sewing, such as sewing
of automobile seat cushions, backs and airbags. It requires not
only high productivity, but also high sewing quality (i.e. good
appearance and long-lasting stitches). Typically, the material
being sewn includes single and multiple plies of synthetic
fabric or leather, and sometimes backed with plastics. These
materials are much more difficult to sew compared to ordinary
sewing applications. In recent years, in order to increase the
sewing productivity, high speed sewing has been used
extensively. Currently, sewing speeds range from
2,000∼6,000rpm. In heavy industrial sewing, typical sewing
speeds range from 1,000∼3,000rpm., needle heating due to the
friction between the needle and the fabric is severe. The
friction generates heat, part of which is absorbed by the fabric
and part by the needle. The heat absorbed by the fabric is
spread out along the seam, but the heat absorbed by the needle
accumulates. Depending on sewing conditions the maximum
needle temperatures range from 100°C∼300°C. This high
temperature weakens the thread, since thread tensile strength is
a function of temperature [1]. and infrared pyrometer[1,2]
These experimental methods are accurate and reliable [2,3].
However, they have a major limitation: they are expensive
(e.g. an IR radiometry measurement device costs thousands of
dollars) and time-consuming (in order to cover various sewing
conditions). Hence, it is inconvenient for shop floor
applications. Brother sewing machine showroom in chennai
Method
To compare the needle eye temperature by thermocamera and
thermocouple following equipments were used
Following machines and instruments were used for this
experiments
1-Lock stitch machine (Brother, DB2 – B755 – 403A)
2-35x3Tex 100%polyester thread (Hagal,Unipoly)Z twisted
TPM=640
3-Thermocople by Omega (TJ36-CAIN-010U-6)
4-thermocouple end wireless device and receiver (MWTC-DK-868)
5-needles(Groz-Becker 90/14)
6-Thermocamera(TMS60)
7-denim fabric (257GSM ,2/1 twill)
8-Fan to cool needle[12Volt DC Fan from ADDA company
(Model:AD0912UX-A7BGL)
Experimental Part
Temperaure 26 o
C and RH 60%
The (TJ36-CAIN-010U-6) thermocouple was inserted inside
the groove of the needle and attached ,the lock stitch machine
was set at 1000,2000 and then 3000 rpm,two layer basic 2/1
twill denim was stitched by 35x3 Tex 100%polyester
thread(commonly used for denim stitching) for continous 90
seconds and temperature was recorded for every second by the
thermocouple for each speed of the machine,Then
thermocamera was adjusted for emmissivity of the needle and
found out to be 0.08 for chromium needle at 38 o
C and then
tested it with callibrated temperature of the needle and found it
correct ,the camera was placed 40cm away from the needle
and again the machine made to stitch at different speeds and
thermocamera took reading at every 10seconds for continous
stitching of 90 seconds,The process was repeated for 5 times
for both thermocouple and thermocamera.
https://vssewingmachine.in/ Results
The Fig 1 shows the needle and the size of thermocouple and
the groove or needle.
Measurement by thermocouple is not non-contact way of
measuring the needle temperature and filling the needle
groove with thermocouple changes its thermal properties but
the Thermocouple shows more precise every second
meaurement of temperature, ,whereas the thermocamera
measurements are with more deviation but still the
observations are near to the temperature measured by the
thermocouple, cooling of needle by external means can reduce
the needle temperature at the stitching process.but the still use
of fan reduce the temperature of needle to some extent and
only a reduction of 15% was noted in the temperature of
needle with the installation of fan,which reduces the
temperature conventionally by flowing air to the needle,the
thread is damages continously as shown by the SEM pictures
by the friction at the needle eye and needle temperatureThis is
part of bigger research eventually the impact on sewing thread
and frictional forces are claculated.
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