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CHAPTER V

YARN QUALITY PARAMETERS OF IMPROVEDCHARKHA

Yarn Quality plays an important part in determining the working

of the loom, appearance of the cloth woven and ultimately the price of

cloth. Better the yarn quality more is the yarn demand for the yarn

and higher will be the market price for good quality yarns. SITRA has

evolved quality standards or Norms for the cotton yarns spun. The

yarns that are produced on the different charkhas have been

ultimately compared for quality against SITRA Norms to see we ,ther

they meet the quality requirements. The quality particulars have been

evaluated for each count that is spun on the charkha

5.1 Yarn Quality Parameters To Be Tested andEvaluated

Yarn samples were spun on all the 3 types of spinning

machines namely 8 Spindle Hand Operated Charkha, 8 Spindle

Motor Operated Charkha and 16 Spindle Improved Charkha. The

roving bobbin of 0.90 hank was taken to Spin 10s' and 33s Nm and

1.20 hank roving was used to spin 64s and 72s Nm. The Spindle

speeds were kept at 5500 rpm and 6500 rpm. Only when the speed

exceed 6500 rpm and above the yarn quality deteriorated due to

excessive end breakages and it was not practical to run the

machine at speeds exceeding 6500 rpm as the stoppage time of the

machine to repair broken threads has become very high. A total of

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\

20 readings for each count was taken to get the average yarn

quality characteristics like CV% of TPI, U%, Thin place/km, Thick

place/km, Neps/km, Rkm values, % of Elongation and Hairiness

Index. The quality particulars of the yarn have been tested and the

results have been analyzed. It can be seen from the test results that

there is vast improvement in yarn quality, obtained with yarn

produced on improved charkha and the quality levels are

comparable with SITRA* norms for mill made yarn of similar counts.

There is also appreciable improvement in yarn quality when shifts

are made from Hand-Operated Charkha to Motorized charkha and

16 Spindle Improved Charkha for all counts. This is because of the

uniform twist flow to the yarn during charkha spinning as the

spindles are driven by motor; this ensures constant speed of

rotation of the machine parts. This stabilization of TPI has yielded

better yarn quality.

5.2.0 Yarn Quality Characteristics

5.2.1 Yarn Quality Characteristics Of 10s Nm spun on charkhas

(5500 rpm and 6500 rpm)

10s Nm** count was spun on the selected charkhas with 5500

rpm and 6500 rpm of spindle speeds .The quality particulars of 10s

Nm count are obtained from 8 Spindle Hand Operated Charkha, 8

Spindle Motor Operated Charkha and 16 Spindle Improved Charkha

are compared with SITRA norms.

* SITRA - South India Textile Research Association, Coimbatore

140

The TPI (Twist Per Inch) 10.0 is given to the yarn, which is kept

constant for all the charkhas.

The trial was taken on 8 Spindle Hand Operated Charkha, 8

Spindle Motor Operated Charkha, 16 Spindle Improved Charkha on

10s Nm at a constant speed of 5500 rpm and 6500 rpm. The yarn

was tested for various parameters like CV% of TPI, U%, Thin

places/km, Thick places/km, Neps/km, Rkm values, Percentage of

Elongation and Hairiness Index. Average of 20 readings for each

quality particulars is given in the Table- 5.1 and 5.2.

5.2.2 CV% of TPI

CV % of TPI affect the working of the yarn in looms. Lower

CV% of TPI is preferable. From the Table -5.1 it is evident that the

CV% of TPI are higher in the yarns made out of 8 Spindle Hand

Operated Charkha, this is because of irregular rotation of handle of

the machine. But the 8 Spindle Motorised Charkha shows 22.4

percentage improvement when compared to 8 Spindle Hand

Operated Charkha. Similarly the CV% of TPI shows 64.2 percentage

improvement in 16 Spindle Improved Charkha when compared with

Hand Operated Charkha and 53.9 percentage improvement when

compared with 8 Spindle Motor Operated Charkha. Even when the

speeds of the charkha were increased to 6500 rpm in Table - 5.2, it

is observed that there is a 30 percentage improvement in CV% of TPI

in the 16 Spindle Improved Charkha.

** Nm - Metric System Of Yarn Numbering

141

5.2.3 U%

U % means uniformity index of the yarn tested is lister

evenness tester (Evenness of yarn). The lower U% means better

quality. The U% rating of 8 Spindle Hand Operated Charkha yam

shows higher values than other two charka yarns. The.re is a 15.3

percentage improvement of U% in the 16 Spindle Improved Charkha

when compared with 8 Spindle Hand Operated Charkha in Table-

5.1. However the SITRA norms give lower values. Among the three

charkhas, 16 spindle motor operated charkha yielded better yarn with

16.56 U% for 10s Nm at 5500 rpm.

5.2.4 THIN PLACES/Km

Table - 5.1 indicates the performance of 10s Nm yarn in terms

of thin places (Yarn imperfections). There is a 82.2 percentage

improvement in the yarn imperfections for 10s Nm count at 5500 rpm

of spindle speeds, between hand operated 8 spindle yarn and 16

Spindle Charkha. The 16 Spindle Charkha has given better quality

than SITRA norms. The 8 Spindle Hand Operated Charkha shows

higher values because of the irregular motion of charkha and jerky

rotation of fluted rollers. But, the 16 Spindle Improved Charkha shows

4 percentage improvement when compared with 8 Spindle Motor

Operated Charkha and 82.2 percentage improvement when

compared with Hand Operated Charkha, because of smooth rotation

of drafting rollers and no vibration in improved machine. This has

confirmed that 16 spindle improved charkha has yielded better results

among the charkhas selected for the study. Even at higher speeds of

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6500 rpm in Table - 5.2, there continues to be reduction of thin

places in yarn spun on improved charkha.

5.2.5 THICK PLACES/Km

Table - 5.1 indicates the performance of thick places at 5500

rpm {Yarn imperfections). There is a 48.6 percentage improvement in

the yarn imperfections for 10s Nm count between 8 spindle hand

operated and 8 spindle motor operated. The 16 Spindle Charkha has

given better quality than SITRA norms and the 16 spindle charkha

has yielded better yarn showing an improvement of 53 percentage

over hand operated charkha yarn and 3.5 percentage improvement

over 8 spindle motor operated charkha yarns. Even at 6500 rpm the

thick places have come down in 16 Spindle Improved Charkha in

Table - 5.2. This was because of smooth rotation of drafting rollers

and no vibration in 16 spindle-improved charkhas.

5.2.6 IMEPS/Km

Neps are defined as entanglement of immature fibers into small

ball the size of a pinhead. The neps undesirable both in the yarn and

the fabric as theyappear as fabric defect. These neps do not qbserii'

the dye applied on to the fabric uniformly, because they consist of

immature fibers. Therefore steps are taken to reduce the nep

generation in the spinning process. It is the blow room and the

carding departments that contribute to nep generation. The neps of

16 Spindle improved Charkha shows 3.48 percentage improvement

in yarn imperfections when compared with 8 Spindle Hand Operated

145

Charkha however the SITRA norms are better probably because

better collons are used in the mills and latest spinning machinery are

available in the mills. Neps generation has been attributed to mainly

the beater speeds, settings in blow room and carding settings

between feed plate and taker in.

5.2.7 TOTAL IMPERFECTIONS/Km

The total imperfections are the sum of thin place, thick place

and neps/Km of yarn. It goes to show the total yarn defects in a

Kilometer of yarn length. Total imperfections influences loom

performance and over all fabric appearance. Less number of

imperfections in yarn is preferred for better yarn quality. The Table-

5.1 indicates that the total imperfections of 10s Nm count shows 57.1

percentage improvement when compared between 8 spindle hand

operated and 16 spindle improved charkhas and 3.6 percentage

improvement in the 16 Spindle Improved Charkha when compared

with 8 Spindle Motor Operated Charkhas. At speeds of 6500 rpm in

Table - 5.2, it is noticed that the total imperfections in 16 Spindle

Charkha is comparable to SITRA quality standards.

5.2.8 RKM VALUES

Stronger the yarn, higher will be the RKM value. Stronger yarns

produce stronger cloth and spin better without end breakage. The

RKM value of 16 Spindle Improved Charkha shows 31.8 percentage

and 4.8 percentage improvement when compared with 8 Spindle

Hand Operated Charkha and 8 Spindle Motor operated Charkha

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respectively at 5500 rpm of spindle speed for 10s Nm. From this

table, the 16 Spindle Improved Charkha values are higher than 8

Spindle Motor Operated Charkha, because of uniform motor speed

and also less vibration of machine. Here the RKM values of different

Charkhas are equal to SITRA norm values. So the higher RKM

means stronger yarns. Hence, it can be inferred that 16 Spindle

Improved Charkha is giving better yarn strength than ring spun yarns.

It can be observed in all the counts spun on the 16 Spindle Charkha,

Rkm values are good and comparable to SITRA quality standards.

5.2.9 PERCENTAGE OF ELONGATION

From the table - 5.1 for 10s Nm Count, it is clear that the

percentage of elongation of 8 Spindle Motor Operated Charkha value

shows 2.6 percentage improvement when compared with Hand

Operated Charkha. There is 4.8 percentage deterioration in

elongation of yarn when compared with 8 Spindle and 16 Spindle

Motor Operated Charkhas. The SITRA norms shows a higher

elongation at break probably because of better raw material used in

spinning mills and also better technology in the blow room and

carding departments.

5.2.10 HAIRINESS INDEX

There is not much improvement in hairiness index in all the

machines when compared with SITRA Norms. The factors

contributing to hairiness in yarn are type of cotton used, processing

parameters, speed of machines, ring and traveller combination etc. If

147

these items are taken care of we can reduce hairiness in the

improved 16 Spindle Charkha yarns.

5.3 Yarn Quality Characteristics of 33s Nm spun on

Charkhas (5500 rpm and 6500 rpm)

5.3.1 33s Nm count was spun on the charkhas using 5500 rpm

and 6500 rpm of spindle speeds. The quality particulars of 33s Nm

count are obtained at 5500 rpm spindle speed by using 8 Spindle

Hand Operated Charkha, 8 Spindle Motor Operated Charkha and 16

Spindle Improved Charkha are compared with SITRA norms in Table

- 5.3. Similarly the charkha speeds were kept at 6500 rpm and 8

Spindle Motor Operated and 16 Spindle Improved Charkha were

compared for quality particulars with SITRA norms. The TPI given to

yarn was 18.0. It was kept constant for all the machines. . .

The yarn was tested for various parameters like CV% of TPI,

U%, Thin places/km, Thick places/km, Neps/km, Rkm values,

Percentage of Elongation and Hairiness Index. Average of 20

readings for each quality particulars is given in the Table- 5.3 and 5.4.

5.3.2 CV% of TPI

From the above table - 5.3, it is evident that the CV% of TPI

are higher in 8 Spindle Hand operated Charkha; this is because of

irregular rotation of handle of the machine. But the 16 spindle

improved charkha shows 37.2 percentage improvement when

compared to 8 Spindle Motor Operated Charkha.

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There is also a 57.6 percentage improvement in CV% of TPI when

compared with Hand Operated Charkha. This is because there is a

uniform twist flow between the nip of the front roller and traveller

because of motorization of charkha. When the speeds are raised to

6500 rpm in Table-5.4, there is a 43.5 percentage improvement in the

CV% of TPI when compared with 8 Spindle Motor Operated Charkha.

5.3.3 U%

U % means uniformity ratio (evenness of yarn). The lower U%

means better quality. The U% of 8 Spindle Hand Operated Charkha

shows higher values than other two charkhas. There is a ,28.07

percentage improvement in U% in the 16 Spindle Improved Charkha

when compared with 8 Spindle Hand Operated Charkha in Table -

5.3. The achievement of U% results in the 16 Spindle Charkha is

better than SITRA Norms. At 6500 rpm of spindle speed, the 33s Nm

colint has shown a 9.6 percentage improvement in U% over 8

Spindle Motorised Charkha.


Table 5.3 indicates the performance of thin places (Yarn

imperfections). There is a 82.7 percentage improvement in the yarn

imperfections (thin places) for 33s Count in the 16 Spindle Charkha

when compared with the results of 8 Spindle Hand Operated

Charkha. The 16 Spindle Charkha values comparable to SITRA\

norms. The 8 Spindle Hand Operated Charkha shows higher values

because of the irregular motion of charkha and jerky rotation of fluted

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rollers. But, the 16 Spindle Improved Charkha shows 20.9 percentage

improvement when compared with 8 Spindle Motor Operated

Charkha, because of smooth rotation of drafting rollers and no

vibration in the improved machine. At 6500 spindle speed for 33s Nm

count, there is 16.6 percentage improvement over 8 Spindle Motor

Operated Charkha in Table-5.4.


Table - 5.3 indicates the performance of thick places (Yarn

imperfections). There is a 71.2 percentage improvement in the yarn

imperfections (thick place) if we compare the performance of 16

Spindle Improved Charkha with 8 Spindle Hand Operated Charkha.

There is also a 12 percentage improvement in 8 Spindle Power

Operated Charkha when compared with 8 Spindle Hand Operated

Charkha. The 16 Spindle Charkha has given better quality than

SITRA norms. The 8 Spindle Hand Operated Charkha shows higher

values because of the irregular motion of charkha and jerky rotation

of fluted rollers. Table - 5.4 indicates the speeds at 6500 rpm for 33s

Count. There is a 26.6 percentage improvement in thick places when

compared to 8 Spindle Motor Operated Charkha.

5.3.6 NEPS/Km

The neps of 16 Spindle Improved Charkha shows 3.3

percentage improvement in yarn imperfections when compared with 8

Spindle Hand Operated Charkha at 5500 rpm in Table-5.3, however

the SITRA norms are better probably because of better cottons are

152

used in the mills and latest spinning machinery are available in the

mills.

5.3.7 TOTAL IMPERFECTIONS/KM

The total imperfections are the sum total of thin place, thick

place and neps/Km of yarn. It goes to show the yarn defects in a

Kilometer of yarn length. From the table 5.3, the total imperfections of

33s Nm count shows 63.5 and 9.5 percentage improvement in 16

Spindle Improved Charkha when compared with 8 Spindle Hand

Operated and 8 Spindle Motor Operated Charkha respectively. The 8

Spindle Hand Operated Charkha shows higher values, because of

jerky rotation of fluted rollers and spindles and uneven twist of yarns.

However the SITRA norms are comparable with the results of 16

Spindle Improved Charkha. At the spindle speed of 6500 rpm, Table-

5.4 indicates 13.3 percentage improvement in 16 Spindle charkha

when compared with 8 spindle charkha.\

5.3.8 RKM VALUES

The RKM value of 16 Spindle Improved Charkha shows 26.4

percentage and 4.3 percentage improvement when compared with 8

Spindle Hand Operated Charkha and 8 Spindle Motor operated

Charkha respectively (Table-5.3). The RKM strength of yarn obtained

on 16 Spindle machines is equal to SITRA norms. There is a

marginal improvement at 6500 rpm also.

5.3.9 PERCENTAGE OF ELOMGATIONFrom the Table- 5.3, it is clear that the percentage of elongation

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in 16 Spindle Improved Charkha shows 22.4 percentage decrease in

elongation when compared with 8 Spindie Hand Operated Charkha

and a decrease of 6 percentage improvement when compared with 8

Spindle Motor Operated Charkha. This marginal decrease in

elongation in the Table- 5.3 and 5.4 is due to use of poor cottons in

the handloom sector.



machines when compared SITRA norms. The factors contributing to

hairiness in yarn are type of cotton used, processing parameters,

speed of machines; ring and traveller combination etc. if these items

are taken care of we can reduce hairiness.

5.4 Yarn Quality Characteristics Of 64sNm spun on

Charkha (5500 rpm and 6500 rpm)

5.4.1 64s Nm count were spun on the charkhas using 5500 rpm

and 6500 rpm of spindle speeds. The quality particulars of 64s Nm

count are obtained from 8 Spindle Hand Operated Charkha, 8

Spindle Motor Operated Charkha and 16 Spindle Improved Charkha

are compared with SITRA Norms.

The trial was taken on 8 Spindle Hand Operated Charkha,

8 Spindle Motor Operated Charkha, 16 Spindle Improved Charkha on

64s Nm at a constant speed of 5500 rpm (Table-5.5) and 6500 rpm

(Table-5.6). The yarn was tested for various parameters like CV% of

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TPI, U%, Thin places/km, Thick places/km, Neps/km, Rkm values, %

of Elongation and Hairiness Index. Average of 20 readings for each

quality particulars is given in the table 5.5 and 5.6. The TPI given to

yarn was 26.0. It was kept constant for all the machines.

5.4.2 CV% of TPI

From the above table 5.5, it is evident that the CV% of TPI are

much higher in 8 Spindle Hand Operated Charkha, this is because of

irregular rotation of handle of the machine. But the 16 Spindle

Improved Charkha shows 36.4 percentage improvement when

compared to 8 Spindle Motor Operated Charkha at 5500 rpm. There

is also a 78.6 percentage improvement in CV% of TPI when

compared with Hand Operated Charkha.This is because there is a

uniform twist flow between the nip of the front roller and traveller

because of motorisation of charkha. At 6500 spindle speeds (Table -

5.6), there is 21.3 percentage improvement in the 16 spindle charkha

when compared with 8 Spindle Motorized Charkha. . .

5.4,3 U%

The U% of 8 Spindle Hand Operated Charkha shows higher

values than other two charkhas. There is a 27.5 percentage

improvement in U% in the 16 Spindle Improved Charkha when

compared with 8 Spindle Hand Operated Charkha in Table-5.5. The

achievement of U% results in the 16 Spindle Charkha are better than

the SITRA Norms at both the spindle speeds.

155


This table 5.5 and 5.6 indicates the performance of thin places

(Yarn imperfections). There is a 80.5 percentage improvement in the

yarn imperfections in 16 Spindle Charkha when compared with the

results of 8 Spindle Hand Operated Charkha for 64s count. The 16

Spindle Charkha values comparable to SITRA norms. The 8 Spindle

Hand Operated Charkha shows higher values because of the

irregular motion of charkha and jerky rotation of fluted rollers. But the

16 Spindle Improved Charkha shows 8.2 percentage improvement

when compared with 8 Spindle Motor Operated Charkha. This is

because of smooth rotation of drafting rollers and no vibration in the

improved machine.


This Table 5.5 and 5.6 indicates the performance of thick

places (Yarn imperfections) at speeds of 5500 rpm and 6500 rpm

respectively. There is a 50.0 percentage improvement in the yarn

imperfections (thick place) if we compare the performance of 16

Spindle Improved Charkha with 8 Spindle Hand Operated Charkha.

There is also a 8.0 percentage improvement in power operated 8

Spindle Charkha when compared with 8 Spindle Hand Operated

Charkha. The 16 Spindle Charkha has given equivalent better quality

than SITRA norms. At 6500 spindle speeds, there is 9.2 percentage

improvement in thick places in 16 Spindle Improved Charkha when

compared with 8 Spindle Motorised Charkha.

158

5.4.6 NEPS/Km

The neps in the do not have any significant contribution in

charkha spinning. As neps are contributed at the carding stage. The

neps per km of charkha yarn compare well with the SITRA norms.

5.4.7 TOTAL IMPERFECTIONS/Km

The table 5.5 and 5.6 indicates that the total imperfections of

64s count shows 49.3 percentage and 4.4 percentage improvement in

16 Spindle Improved Charkha when compared with 8 Spindle Hand

Operated and 8 Spindle Motor Operated Charkha respectively at

5500 rpm. At 6500 rpm the 16 Spindle Improved Charkha shows 7.8

percentage improvement in Total imperfections. The results of the 16

Spindle Improved Charkha compare well with SITRA norms.

5.4.8 RKM VALUES

Referring to Table - 5.5 and 5.6, the RKM value of 16 Spindle

Improved Charkha shows 68.9 percentage improvement when

compared with 8 Spindle Hand Operated Charkha and 9.2

percentage improvement at 5500 rpm and 4.3 percentage

improvement in 6500 rpm in yarn strength when compared with 8

Spindle Motor Operated Charkha. The RKM strength of yarn obtained

on 16 spindle machines is equal to SITRA norms.

5.4.9 PERCENTAGE OF ELONGATION

From the Tables -5.5 and 5.6, it is clear that the percentage of

elongation in 16 Spindle Improved Charkha shows 15.5 percentage

decrease when compared with 8 Spindle Hand Operated Charkha

and a decrease of 7.2 and 4.3 percentage when compared with 8

Spindle Motor Operated Charkhas in Table -5.5 and 5.6.



machines when compared with SITRA Norms. The factors

contributing to hairiness in yarn are type of cotton used, processing

parameters, speed of machines; ring and traveller combination etc. if

these items are taken care of we can reduce hairiness.

5.5 Yarn Quality Characteristics Of 72s Nm spun on

Charkhas (5500 rpm and 6500 rpm)

5.6.1 72s Nm count was spun on the charkhas using 5500 rpm

and 6500 rpm of spindle speeds .The quality particulars of 72s Nm

count are obtained from 8 Spindle Hand Operated Charkha, 8

Spindle Motor Operated Charkha, and 16 Spindle Improved Charkha

are compared with SITRA norms. The TPI given to yarn was 28.0. It

was kept constant for all the machines.

The yarn was tested for various parameters like CV% of TPI, U%,

Thin places/km, Thick places/km, Neps/km, Total imperfections/Km,

Rkm values, Percentage of Elongation, and Hairiness Index. Average

of 20 readings are given for each quality particulars in the Tables -

5.7 and 5.8. •

160

5.5.2 CV % OF TPS

The Tables - 5.7 and 5.8, shows that the CV% of TPI are

much higher in 8 Spindle Hand Operated Charkha.This is because of

irregular rotation of handle of the machine. But the 16 Spindle

Improved Charkha shows 10 percentage improvement when

compared to 8 Spindle Motor Operated Charkha at 5500 rpm and 14

percentage improvement when the speed is increased to 6500 rpm

for 72s Nm count. There is also a 63.4 percentage improvement in

CV% of TPI when compared with Hand operated Charkha. This is

because there is a uniform twist flow between the nip of the front

roller and traveller because of motorization of charkha.

5.5.3 U %

The U% of 8 Spindle Hand Operated Charkha shows higher

values than other two charkhas. There is a 21.8 percentage

improvement in U% in the 16 Spindle Improved Charkha when

compared with 8 Spindle Hand Operated charkha at 5500 rpm and

5.6 percentage improvement at 6500 rpm for 72s count when

compared with 8 Spindle Motorised Charkha. The achievement of

U% results in the 16 Spindle Charkha are better than the SITRA

norms at both the speeds.


The tables 5.7 and 5.8 indicate the performance of thin places

(Yarn imperfections). There is a 81,7 percentage improvement in the

163

yam imperfections (thin places) in the 16 Spindle Charkha when

compared with the results of 8 Spindle Hand Operated charkha. The

16 Spindle Charkha values comparable to SITRA norms. The 8

Spindle Hand Operated Charkha shows higher values because of the

irregular motion of charkha and jerky rotation of fluted rollers. But, the

16 Spindle Improved Charkha shows 16.3 percentage improvement

when compared with 8 Spindle Motor Operated Charkha, because of

smooth rotation of drafting rollers and no vibration in the improved

machine. When the speed is increased to 6500 rpm and compare the

yarn quality (thin places), it is found that there is 17.2 percentage

improvement in the new charkha.


The tables - 5.7 and 5.8 indicate the performance of thick

places (Yarn imperfections). There is a 53 percentage improvement

in the yarn imperfections (thick place) when compared with the

performance of 16 Spindle Improved Charkha to 8 Spindle Hand

Operated Charkha (Table - 5.7). There is also a 48.3 percentage

improvement in power operated 8 Spindle Charkha when compared

with 8 Spindle Hand Operated Charkha. There is a slight deteoriation

in 16 Spindle Improved Charkha when compared to SITRA norms. At

6500 spindle speed the thick places show a reduction of 16.5

percentage in thick places in 16 Spindle Charkha.

5.5.6 NEPS/Km

The neps do not have any significant contribution in charkha

164

spinning. As neps are contributed at the carding stage. The neps per

km of charkha yarn compare well with the SITRA norms.

5,5.7 TOTAL IMPERFECTIONS/Km

From the Table - 5.7, the total imperfections of 72s Nm count

shows 53.4 percentage and 11.5 percentage improvement in 16

Spindle Improved Charkha when compared with 8 Spindle Hand

Operated and 8 Spindle motor Operated Charkha respectively. The

results of the 16 spindle improved charkha compare well with SITRA

norms. In the Table - 5.8 at 6500 rpm of spindle speed there is a

reduction of 14.1 percentage in the total imperfections in the yarn that

is spun on the 16 Spindle Charkha. Even at such high speeds the

total yarn imperfections obtained on the new charkha are comparable

with SITRA norms.

5.5.8 RKM VALUES

The RKM value of 16 Spindle Improved Charkha shows 19

percentage improvement when compared with 8 Spindle Hand

Operated Charkha and 2 percentage improvement in yarn strength

when compared with 8 Spindle Motor Operated Charkha (Table-5.7).

The RKM strength of yarn obtained on 16 Spindle machine is equal to

SITRA norms. At higher speeds of 6500 rpm (Table - 5.8), the RKM

strength obtained on the 16 Spindle Charkha is comparable to SITRA

norms This proves the hypothesis that better yarn quality can be

produced on 16 Spindle Improved Charkha.

5,5.9 PERCENTAGE OF ELONGATION.

From the Tables - 5.7 and 5.8, it is clear that the percentage of

elongation in 16 Spindle Improved Charkha shows 32.1 percentage

decrease in elongation when compared with 8 Spindle Hand

Operated Charkha and a decrease of 3.6 percentage when compared

with 8 Spindle Motor Operated Charkha at 5500 rpm. Similarly there

is a 18.5 percentage decrease in elongation in the 16 Spindle

Charkha at 6500 rpm when compared with 8 Spindle Motorised

Charkha.\



machines when compared with SITRA norms. The factors

contributing to hariness in yarn are type of cotton used, processing

parameters, speed of machines; ring and traveller combination etc if

these items are taken care of we can reduce hairiness.

5.10 Ratings For Yarn Appearance Using ASTM Boards

Count SITRA Norms Actual Ratings

Achieved

20's to 100’s Carded D D

Counts

Yams samples taken from 16 Spindle Charkha wrapped on

ASTM Boards and compared with SITRA norms. The findings are

comparable to the mill yarns in both appearance and quality.

166

This proves the hypothesis that the yarn quality and yarn

appearance of yarns produced on the 16 Spindle Improved Charkha

is comparable to the yarns that are produced in the textile mills the

counts being similar. The new charkha that has been developed

produce yarns in all counts ranges with comparable yarn quality. With

spindle speeds beyond 6500 rpm it was found that the thread

breakage was higher resulting in lot of time waste in repairing the

broken threads. This resulted in loss of machine efficiency. The

reason for excessive thread breaks was due to poor quality roving

used. More trials with better quality roving and at higher spindle

speeds could be tried out. Generally higher spindle speeds, gives

higher productivity and even better wage earnings.

SUMMARY

The applicability and use of any yarn will be determined by the

quality of it. General yarn quality parameters that any buyer will look

for will be count, TPI, CV% of TPI, U%, Thin places/Km, Thick

places/Km, Neps/Km, Total imperfections/Km, Rkm values (Gms/

tex), Elongation percentage and Hairiness index etc. The above

parameters were evaluated with the yarns produced in three

charkhas namely 8 Spindle Hand Operated Charkha, 8 Spindle Motor

Operated Charkha and 16 Spindle Improved Charkha for different

counts ie 10s Nm, 33s Nm, 64s Nm, 72s Nm. In all the above counts of

yarn, it has been observed that improvements in the quality

parameters were established and some of the parameters were on

par with SITRA norms for yam quality. The yarn appearance ASTM

187

standard has been complied by the yarn produced in the improved

design charkha. The SITRA Norms are for the yarns made in the mill

spinning. But in the present work, 8 Spindle Motor Operated Charkha,

16" Spindle Improved Charkha has yielded improved quality yarns

proving way for its adoption and commercial sales.

Thus the hypothesis stating that by incorporating the improved

design of the charkha, the quality parameters of the output yarn has

been improved in terms of CV% of TPI, U%, Thin places/Km, Thick

Places/Km, Total imperfections, Rkm Values, Percentage of

Elongation and Hairiness index has also been proved.

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