Process Flow Chart of Sewing Thread | Different Types of Packages areUsed in Sewing Threads

A thread is a large number of very thin fibers spun together, used in the manufacture of textiles and in sewing. Or In hardware a thread is used to connect two things together, such as a screw to a piece of wood or two segments of a hose.

The process flow chart for the manufacture of sewing threads is shown in the flow chart.

Functions of various machines in sewing thread manufacturing process:

Yarn singeing

Sewing thread must be singed to ensure that the projecting fibres do not interfere with downstream processing. Percentage of singeing can be achieved varied by varying the yarn collection speed. Hair removal efficiency at singeing machine is normally 30 - 50%. Flame temperature is around 800 oC. Singeing is mainly done in Cotton Sewing Threads.

Features

1. The heart of the machine - the burner, serves to singe reliably the projecting fibres of yarn running through at high speed, without inflicting burns on yarn itself. There is a choice between the gas burner and the electric burner. Gas burner are widely used. The gas burner consumes about 55 gm of natural, propane or butane gas an hour, depending on singeing rate and yarn type. 
2. Speed: 300-1200 m/min.

Hank to cone winding

• Conversion of hank in to cone of suitable weight

• Waxing for reducing co-officient of friction in sewing thread .

Features of new machines:

• Twin Input Rollers: At the front of the head are the twin-input rollers, set to a fixed speed but proportional to the winding speed. The main functions of this unit are to eliminate unwanted tensions prior to yarn entering waxing unit. 

• The speed of machine ranging from 400-700 mpm, with possible traverse from150-200 mm.

Polishing

Some threads for special end uses like leather industries, bag stitching, kite flying are treated with starch, softeners, whitener, etc on this machine. Cooked starch is mixed with other chemicals and different recipes are made for different qualities depending on the end uses. 

Main objectives of polishing are:

• Extra ordinary smooth surface 

• Thread becomes round.

• Stiffness increases.

• Increase in tensile strength (7-10%).

Cross winding and lubrication

• Winding in various types of sewing thread packages like cone, cop , tube, ball, vicone and spool.

• Threads are treated with special waxes for achieving best workability during sewing operation.

• Lick roller lubrication is applied on industrial sewing thread where thread has to run on high speed sewing machine; the basic ingredient of the most of the lubricants is parafin wax. Although silicones are also used because of their stability to heat and various additives are also included to give some special properties.

Geometry of packages

Threads are wound in many forms. Small length spools are employed in retail store distribution, whereas somewhat larger spools are used to a limited extent industrially. Some of the very fine soft threads are wound on cones, very coarse soft threads are in skein form, but the largest proportion by far is wound on the one headed tube with base or straight tubes. These packages in some instances are put on a weight basis; however, the larger percentage is marked on a length basis. Ready-wound bobbins in a number of styles to accommodate the various sewing machines employed are also available. Cross winding threads are generally laid in with traverse ratio 1: 6 (one double traverse = six spindle revolution) and 1: 4 for coarser counts.

The following types of packages are used in sewing threads (with commonly used dimensions).

Spool: Spools are small flanged plastic or wooden bobbins, they are both with tapered (so-called Diabolo spools) and straight flanges. Mainly parallel winding (because side unwinding is easy) is done. Cross-windings are also possible on the spools. They contain relatively short length of 100-500 meter thread. The length of traverse on spool is 2.9-3.8 cm.

End uses: Upholstery, footwear, leather goods manufacturing, and in hand sewing operations. 

Cop:

Cops are small cylindrical flangeless spools, with precision cross winding. They are mostly made of paper and plastic. They are of two types, small Cop (Tube) and medium Cop (Cop). The lack of flanges facilitates regular off winding on industrial sewing machines although their small diameter makes them less well suited to the faster thread take off machines. Smaller Cops are popular make-up in fashion trades, where a variety of shades are used and production runs for any one colour or style of garments. The length of thread wound ranges from 100-2000 m on small cop and 400-4000 m on cop. The length of traverse on small cop is 5 - 6.3 cm and on cop is10 cm.

End uses: Kite flying, Upholstery, ready-made garment, tailoring, hosiery, umbrella, and shoe stitching

Cone: 

This is self-supporting, cross wound conical package. It is easier to withdraw yarn over end from a cone than from a cheese and because of this, cone is more widely used. They contain relatively long lengths 1000-25000 m with length of traverse ranging from 10-15 cm. They give trouble free thread unwinding at intermittent or continuous high speeds. Cones are the most economical packages for conventional sewing threads in situations where thread consumption is high and production runs are long.

End uses: ready made garment, tailoring, hosiery, leather stitching, Upholstery, shoe stitching, denim, embroidery, and kite flying.

Vicone or King Spool: 

Vicones are parallel tubes or low angled cones with an additional base in the form of a raised flange, which may incorporate a small tip. The build of vicone depends on the exact conformity of the taper with the angle of vicone’s base. Coarse yarns require a large traverse for the taper — fine yarn a small one. They contain lengths of 1000-5000 m with length of traverse 6.5-9 cm.

End uses: embroidery, core-spun, and filament threads .

Prewound Bobbin:

Prewound bobbins are precision parallel wound thread package designed to replace metal bobbins on a variety of lock stitch machines.

Skein: 

A very small hank of soft twisted plied thread (around 8 m) of coarse count, is parallel wound with the help rotating flyer, which withdraws the thread from the supply package cone. 

End uses: embroidery.

Ball: 

A typical ball like structure, wound with the help of four types of different winding. They are: Rough base winding, form winding, surface layer winding, and circumference winding. The initial winding provides firmness at the base. Next winding process makes space for placing the identification ticket. The third stage of winding provides firm gripping of the ticket. The last stage of winding makes a band over the ball, which retains its shape. An easy unwinding of thread is possible.

End uses: embroidery, fishing net and bag closing.

Cocoon: 

Cocoons are self-supporting i.e. center-less thread package specially designed for the insertion in the shuttle of multi needle quilting and some types of embroidery. Cocoons are used in the shuttle of multi needle quilting and some types of embroidery machines.

Determination of Yarn Strength | Determination of Single Jute YarnStrength

Name of the Experiment: Determination of single jute yarn strength and quality ratio.

Introduction:
The strength of a yarn gives us an idea how much load we can apply on it and it is very important for different process of yarn. On the other hand quality ratio of yarn indicates how good or bad the yarn is. Therefore, the experiment has two objects: 

1. To find out the strength and quality ratio of yarn.
2. To assume about the quality of yarn.

Theory:
Quality ratio is the ratio in percent of single yarn strength (lb) and yarn count (lb/spyndle). Single yarn strength in lb Jute yarn count in lb/spyndle i.e. Quality Ratio = X 100 .Again, count lb/spyndle is the weight of yarn in lbs per 14400 yards.
 

Figure: The pendulum lever principle

Count = (WXl)/(LXw)
Here, L = length of the sample & l = unit length of the system
W = wt. Of the sample & w = unit wt. of the system. 

A lea strength tester measures the strength of one lea yarn. One lea means 120 yards. Strength is a measure
of the steady force necessary to break a material and is measured in pound. The m/c works in constant rate of
extension. Assuming the specimen to be extensible and an absence of any dynamic effects, we get from the figure:

Fr = Mgr = MgRsinθ 
As the value of MgR and r are constant, therefore
F∞sin θ  . 

According to the applied force the m/c dial gives us the strength in lb on the basis of this θ  . 

Apparatus:
1.Wrap reel
2. Lea strength tester
3. Electrical balance

M/c specification:
The Lea Strength Tester
Goodbrand & Co. Ltd.
Capacity: 25 lb

Testing atmosphere:
Temperature – 29oC and relative humidity – 76%
Standard atmosphere: temperature – 20oC and relative humidity - 65%.

Sample:
Size for count – 25 yards and for strength – 24 inches Jute yarn.
No. of sample for count – 5 and for strength – 20.

Working Procedure:
1. At first 25 yards jute yarn is measured by wrap reel and in this way 5 samples are taken for count testing.
2. Then all the samples are weighted and counts are calculated.
3. Now a single 24 inches yarn from 1st sample is fixed between the jaw J1 and J2.
4. The m/c is started and observed the dial until the yarn is torn out.
5. When the yarn is torn out the m/c is stopped and the reading is taken.
6. By this way the reading of other yarns from other samples are taken.
7. Quality ratio of the all samples are calculated.
8. At last average and CV% are calculated.

Data:

Yarn count:
 

SL no.	Length in yds	Weight in gms	Count (lb/spyndle)	Average
1	25	23.8	30.22	29
2		24.7	31.37
3		21.78	27.66
4		21.95	27.87
5		22.05	28

 

Yarn strength and quality ratio:

 

SL no.	Length in inches	Weight in lbs	Average	Quality ratio	Average
1	24	20.3	20.13	70	73.25
2		24.4		84
3		25		86
4		19.6		67

Calculation: 

Result:
The strength of jute yarn is 20.13 lbs and quality ratio is 73.25.

Remark:
It is considered that fibres having quality ratio less than 80 are bad or weak, between 80-100 are average and greater than 100 are strong. From our experiment we see that the quality ratio of the sample is less than 80 and CV% is 5.89. This proves that there are many variations in this test. So finally we can say that these yarns are averagely low strength fibres. But it may be vary because our testing atmosphere is not standard.