Download - Stitch Machines
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OPERATION FLOW IN A GARMENTFACTORY( Stitching)
Sewing Machine Feeding System
Throat plateProvides openings forthe needle and the feed dog
The needle hole in throatplate should be onlyabout 30percent larger than the size of theneedle, since if this hole is too large , fabric canbe pushed into the hole with each penetrationof the needle , a problem known as flagging.
The surface of the throatplate should be free ofcuts orabrasion. to enable the material to freely
pass over it without damaging the fabric.
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OPERATION FLOW IN A GARMENTFACTORY( Stitching)
Sewing Machine FeedingSystem
Feed DogThe purpose of the feed dog is tomove the fabric along by a
predetermined amount betweensuccessive stitches.
Types of feed dog teeth: Saw tooth ( Single direction feeding) Upright ( Uniform two direction
feeding)
Diamond ( feedingof fine fabric)
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OPERATION FLOW IN A GARMENTFACTORY( Stitching)
Sewing Machine Feeding System
Feed Dog ( Considerations) The motion of the needle in up and down
direction must be accurately synchronized with
the elliptical motion of the feed dog so that themovementof the fabriconly takes place whenthe needle is outof the fabric.
Forsewing light to medium weight fabrics, atooth pitch ( distance from peak topeak) of 1.3to 1.6 mm is normal
The peaks can be slightlyroundedoff if damageoccurs on fine fabric.
On very light weight fabric, sagging can appearbetween the teeth andpuckercan occuraftersewing as a result. Fine toothed feed dog with apitch ofonly 1.0 to 1.25 mm can be used toprevent this.
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OPERATION FLOW IN A GARMENTFACTORY( Stitching)
Sewing Machine Feeding System
Feed Dog ( Considerations) On heavyweight fabric a certain amountof sagging is
required forsatisfactory feeding in orderto keep bothplies together. In this case, coarserfeed dogs of 2.5
mm tooth pitch may be used. On very delicate fabrics, damage ormarkingof the
fabric may arise against the feed dog, despiteroundingoff the teeth. In this case a rubbercoatedfeed dog with no sharp teeth at all may be used.
Of more importance in preventing damage duringfeeding is a deliberate mismatch between stitch sizeand feed dog size. If forexample a seam is sewn at 6stitchespercm using a feed dog with 6 teeth percm ,then a tooth willrepeatedly hit the same section of thefabric as it moves past and markingof the fabricoreven damage couldoccur.
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OPERATION FLOW IN A GARMENTFACTORY( Stitching)
Sewing Machine Feeding
System
PresserFoot Presses the material being
sewn against the feed dog and
the throatplate.
Facilitates stitch formation andfeeding
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OPERATION FLOW IN A GARMENTFACTORY( Stitching)
Needle
The needle has to be able topenetrate the material being
sewn , without damaging it ,by pushing the yarn side.
Selection of the needle sizewill depend upon :
Material being sewn
The size of sewing thread
The type of seam
Stitch type
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OPERATION FLOW IN A GARMENTFACTORY( Stitching Dept.)
Needles for Textile
Cloth point needles are usedfor sewing textile materialwhich has a round crosssection and the tip at the endof the point can vary inshape to suit the particularmaterial being sewn. Clothpoints needle can further beclassified as:
Set point needle Ball point needle
Cutting point needles areused sewing leather andlaminated textiles.
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OPERATION FLOW IN A GARMENTFACTORY( Stitching Dept.)
Set point Needles
Slim set point needle:needles
Used for fine, denselywoven fabric but not suitablefor knitted fabric.
Set cloth point:Slightly rounded.
Displaces the yarns ofmaterial being sewn w/odamaging.Most versatile
point shape. Heavy set point :
Strongly blunted.Especially used for buttonsewing machine
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OPERATION FLOW IN A GARMENTFACTORY( Stitching Dept.)
Ball point Needles
Light Ball Point
Used for sensitive
fabrics such as knits toprevent damage to the loop.
Medium & Heavy Ball
point:
Used for elastic material
containing elastomericthreads . The threads are
not pierced but displaced.
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OPERATION FLOW IN A GARMENTFACTORY( Stitching Dept.)
Single Needle lock
stitch machine
2- Needle lock stitch
machine
Sewing Machines
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OPERATION FLOW IN A GARMENTFACTORY( Stitching Dept.)
Over-lock/ Safety
stitch machine
High speed flat bed top and bottom
stitch machine ( 2 needle / 3
needle
Sewing Machines
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OPERATION FLOW IN A GARMENTFACTORY( Stitching Dept.)
Button Sewing
machine
Button Sewing machine
with tying knot
Sewing Machines
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OPERATION FLOW IN A GARMENTFACTORY( Stitching Dept.)
Cylinder bed lockstitch
Bartacking machine
1-Needle Button holing
machine
Sewing Machines
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OPERATION FLOW IN A GARMENT
FACTORY(SAMPLE DEVELOPMENT )
DOS & DONTS
Develop and document a standardoperatingprocedureforthe article clearly describing each step and theaccepted quality level.
The production manger/ supervisormust involve in thesample development and be instructed topracticallyshow the standard method to each stitchingoperator.
Repeated instructions and close followup is utmostimportance in producing the desiredresults.
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OPERATION FLOW IN A GARMENT
FACTORY(SAMPLE DEVELOPMENT )
DOS & DONTS
Once the operations procedures are set, time and motionstudy must be carriedout.
Economyof motion must be emphasized and dailyproduction targets must be seton its basis.
Balancingof line should be basedon time study( seeguidelines in the chapter on Method Study).
Sampling must be carriedout with the objective tosmoothen and enhance theproduction.
Properplanning and improvements basedon the findings ofpre -production samples ensure less hurdles in productivityand consistent improved quality..
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OPERATION FLOW IN A GARMENT
FACTORY(SAMPLE DEVELOPMENT )
DOS & DONTS
Use of Dummy
Apart from conformance to the buyers specs. , it is veryuseful
to check the overall fittingof the garmentusing dummy.
Machine Setting
To avoid such problem owing to highertension of the boot, the
operators should always check for suitable machine settings
fordifferent types of fabric.Each operatorshould be provided a piece of fabricof which is
to be run in production and machineperformance should be
checkedon it before sewing theproduction pieces.
It is the responsibilityof Sample Room to initially communicate
the machineparameters to the productionpeople.