images pdfs may june2014

7/25/2019 Images Pdfs May June2014

http://slidepdf.com/reader/full/images-pdfs-may-june2014 1/32

May - June 2014

SITRA News 1

This issue of SITRA NEWS

covers the fol low ing top ics:

Page no.

PRODUCTIVITY AND COSTS

How RMC and YSP had fluctuated in 2013-14? 1

TECHNICAL NOTES

1. How to ascertain the statistical significance

of the difference in end breaks between

ringframes ? ― An investigation 4

2. A simple method for calculation of approxi

mate density of cheese yarn packages 8

PROJECTS

Studies on thermally conductive filament

incorporated hospital bed linens 10

ARTIFICIAL NEURAL NETWORK - Series 7 16

CONSULTANCY SERVICES OFFERED BY SITRADURING MAY – JUNE 2014 19

STAFF NEWS 19

TRAINING PROGRAMMES 21

ABSTRACTS OF TECHNICAL ARTICLES 25



May - June 2014

SITRA News 1

How RMC and YSP had fluctuated in 2013-14?

In recent years the commercial parameters viz., yarn selling price

(YSP) and raw material cost (RMC) have been fluctuating widely; on a

few occasions they had even touched the unexpected values, thus

having a direct impact on the profit margin of spinning mills.

Using the count-wise RMC and YSP data that were furnished by the

mills in the first 12 online surveys (April 2013 to March 2014), an

analysis was made to study the fluctuations in the YSP, RMC and

NOV (net output value) of 11 popular counts, covering coarse to super

fine, between months in 2013-14 and the salient findings are given in

this note. Besides, the predicted net profit margin for these 11 counts

is also given. The following counts and varieties of yarns have been

considered for the analysis:

Chang es in th e commerc ial parameters in 2013-14 (average of 11

counts)

‘*’ Percentage points

Note: (-)ve sign indicates drop

40s K 40s C-Comp. 30s CH

40s C 50s C-Comp. 40s CH

60s C 60s C-Comp.

80s C 80s C-Comp.

100s C

Parameter Mean

deviation (%)

Increase in the values in March2014 over April 2013

% (Rs/kg of yarn)

YSP 2.1 4 12

RMC 5.1 18 27

RMC/YSP 3.7 13 6*

NOV 4.2 (-) 9 (-) 15



May - June 2014

SITRA News 2

The fluctuation in the YSP between months in all the 11 counts

and varieties of yarns put together amounted to about 2%. On

the other hand, the RMC had registered almost a 2.5 timeshigher fluctuation. As a result of the above, the NOV had

registered a high fluctuation of about 4% between months.

Between April 2013 and March 2014, the increase in the RMC

was very high at 18%. In absolute value, the increase amounted

to Rs 27 per kg of yarn, ranging from Rs 13 per kg of yarn

increase in 30s CH to Rs 54 per kg of yarn increase in 80s C-

Comp. counts.

Though the YSP also had registered an increase of 4 % in

March 2014, nevertheless, it was not helpful to arrest the drop

in the NOV. The NOV had registered a big drop of 9% in March

2014.

The 6 percentage points increase in the RMC relative to YSP

would have lowered the profit margin of many mills in March

2014.

Prof i tabi l i ty in d i f ferent coun ts

Taking into account the 12 months’ average YSP and RMC values and

average conversion cost that prevailed in 2013-14, the predicted net

profit margin was worked out for all the 11 counts (Table 1 and Figure

1).

In 2013-14, mills would have earned a net profit margin in many counts.

For instance, out of the 11 counts that have been considered in the

analysis, as many as 9 counts would have earned a net profit marginranging from about 2% to over 10% of the YSP. In the remaining two

counts, 60s C count had registered almost a break-even profit while

40s K count had recorded a dismal performance.

It is interesting to observe that the compact yarns, particularly 40s,

50s and 60s counts would have earned a very high profit margin of

around 10% of the YSP when compared to the non-compact yarns.

Even 80s C-Comp. yarn would have earned a reasonable profit margin

of around 4%.



May - June 2014

SITRA News 3

Table 1 Predicted net profit margin in different counts in 2013-14

Note: (-) ve sign indicates net loss

Figure 1 Predicted net profit margin in different counts in 2013-14

CountNOV

(Rs/kg of

yarn)

Conversioncost (Rs/kg of

yarn) (CC)

Net profit margin(NOV-CC)

Rs/kg of yarn

As a % of YSP

40s K 78 88 (-) 10 (-) 4.7

40s C 87 77 10 4.2

60s C 129 132 (-) 3 (-) 1.0

80s C 190 184 6 1.6

100s C 242 230 12 2.7

40s C-Comp. 100 74 26 10.4

50s C-Comp. 137 101 36 12.4

60s C-Comp. 160 132 28 8.8

80s C-Comp. 223 207 16 3.9

30s CH 62 57 5 2.3

40s CH 81 65 16 6.9

8.8

6.9

2.33.9

12.4

-4.7

4.2

-1

1.6

2.7

10.4

-5

0

5

10

15

P r o

f i t / l o s s ( a s a %

o f Y S P )

4 0 s K

4 0 s C

6 0 s C

8 0 s C

1 0 0 s C

4 0 s C - C o m p .

6 0 s C - C o m p .

5 0 s C - C o m p .

8 0 s C - C o m p .

3 0 s C H

4 0 s C H

Counts



May - June 2014

SITRA News 4

References

1. Nagarajan N K, Subash P, Raj Kumar S and Shanmuganandam D Online Survey of Raw Material Cost and Yarn Selling Price

– SITRA publications (12 surveys: April 2013 to March 2014).

2. Sreenivasan J and Shanmuganandam D

An inter-mill study on fibre to yarn conversion cost – 3rd study

Vol.58, No.4, January 2014.

- D.Shanmuganandam

Liaison and Consultation Division

1. How to ascertain the statistical significance of thedifference in end breaks between ringframes ?

― An investigation

Four ringframes were observed for end breaks and the results are

given in Table 1.

Table 1 No. of end breaks in different ringframes

Is there any evidence to conclude that the end breakage rates differ

between machines?

- Total no. of end breaks = 425

RingframeDuration of observation

(spindle hours)No. of end breaks

A 500 50

B 1000 120

C 1000 150

D 800 105



May - June 2014

SITRA News 5

- Total duration of observation of end breaks = 3300 sple hrs.

- Breaks / Sple hour = 425

3300

= 0.129

: Expected no. of breaks for 500 sple hrs = 0.129 x 500

(Ringframe A) = 64


(Ringframe B) = 129


(Ringframe C) = 129


(Ringframe D) = 103

After this, 2 test has to be applied to decide as to whether the end

breaks rates between machines differ significantly.

To carry out the 2 test of significance, the following table. (Table 2)

has to be formed.

Table 2 Actual & expected no. of end breaks in different ringframes

The calculated value of 2 (7.15) has to be compared with 2value from2 table for 3 degrees of freedom* at 95% significant level.

Ringframe Actual end breaks

(O)

Expected end breaks(E)

(O - E)2

E

A 50 64 3.06

B 120 129 0.63

C 150 129 3.42

D 105 103 0.04

Total 7.15

2=

* Degrees of freedom (DF) = No. of observations – 1

Hence, in this case, 4 – 1 = 3



May - June 2014

SITRA News 6

A condensed version of 2 table is given below (Table 3).

Table 3 2 values for different degrees of freedom

The 2 value from 2 table for 3 DF is 7.81. Since the calculated value

of 2 (7.15) is lower than the 2 value given in 2 table (7.81), it may be

inferred that the end breakage rate does not differ significantly between

ringframes.

Caution

While applying the 2 test, it should be ensured that adjusted data is

not utilised. Only the actual observed values should be used if the

conclusions are to be correct.

For example, let us convert the observations given in Table 1 to end

breaks for 2000 spindle hrs in each case even though the actualobservations have been for different periods. Then we will have a table

of the following type (Table 4) for the number of end breaks in different

ringframes.

Degrees of freedom 2Value Degrees of freedom 2

Value

1 3.84 11 19.88

2 5.99 12 21.03

3 7.81 13 22.36

4 9.49 14 22.68

5 11.07 15 25.00

6 12.59 16 26.03

7 14.07 17 27.59

8 15.51 18 28.87

9 16.92 19 36.19

10 18.31 20 31.41



May - June 2014

SITRA News 7

Table 4 No. of end breaks in different ringframes

(Duration of observation converted to 2000 sple hrs)

For the data given in Table 4, the 2 value = 21.0. (Table 5).

Table 5 Actual & Expected no. of end breaks in different ringframes

(Duration of observation converted to 2000 sple hrs)

This 2value (21.1) is higher than the 2value from 2 table for 3 degrees

of freedom (7.81).

The inference from this result would be that, the breakage rates differ

between ring frames which would be a misleading conclusion.

Hence, when we apply the 2 test in a particular case, data collected

in the concerned experiment should be used in their original form and

should not be reduced to their lower or increased to higher denominants

of percentages, unit time of observation, etc.

- Dr. K.P.Chellamani

Spinning Division

Ringframe End breaks

A 200

B 240

C 300

D 262

Ringframe Actual end breaks

(O)

Expected end breaks

(E)2

(O - E)2

E

A 200 250 10.0

B 240 250 0.4

C 300 250 10.0

D 263 250 0.7

Total 21.1

=



May - June 2014

SITRA News 8

2. A simple method for calculation of approximatedensity of cheese yarn packages

The density of packages plays a vital role in deciding the levelness of

dyeing during yarn package dyeing. Packages having varying and / or

improper densities often result in uneven dyeing and hence rejections.

However, the measurement of density in the real sense is a little

complicated. The ideal method for measurement of package density

is by measuring the volume of yarn by displacement and calculating

the weight per volume (i.e) density. Even in this method, there is no

correction factor for the absorption of water by the yarn. Also, mills

hardly get time to wait for the measurement of package density by

this method as they will be in a hurry to send the packages for dyeing.

In such a scenario, the following formula will be handy for calculating

the yarn package density of cheese packages:

Density is expressed as weight per volume. Hence, the density of a

cheese package would be,

Weight of yarn wound in grams

Density of cheese = —————————————————————package (g / cm3) Volume of yarn wound on the package in cm3

Cheese Package Density Calculation:

Step 1: Weigh the full cheese package with the dye spring or perforated

cheese W1 in grams

Step 2: Measure the average weight of the empty dye spring or

perforated cheese W2 in grams

Step 3: Measure the outer diameter of the full cheese package using a

Vernier caliper D1 in cm

Step 4: Measure the outer diameter of the empty cheese using a Vernier

caliper D2 in cm

Step 5: Measure the height of yarn wound along the vertical axis of

the package H in cm



May - June 2014

SITRA News 9

Step 6: Apply the following formula and calculate the package

density

(W1 – W

2) x 4

Density of cheese yarn package = —————————

π x (D1

2 – D22) x H

Example:

Weight of cheese full package W1

= 1227 g.

Weight of empty cheese W2

= 55 g.

Outer diameter of full cheese package D1

= 18.5 cm

Outer diameter of empty cheese D2

= 6.8 cm

Height of yarn wound on full cheese package H = 14.8 cm

(1227 – 55) x 4

= —————————-— =

π x (18.52 – 6.82) x 14.8

Using the above formula the approximate density of a cheese package

can be calculated within minutes and hence it helps in taking quick

decisions during soft package winding. For better dyeing results,

cheese package density for cotton yarn should be maintained between

0.25 and 0.35g/cm3 or 250 g/l to 350 g/l, depending upon the count of

yarn. The ideal cheese package density for polyester yarn would be

between 0.40 and 0.45g/cm3 or 400 g/l to 450 g/l.

Another variable which decides the uniformity of dyeing within a batch

of cheeses is the length of yarn wound on the cheeses. It is ideal to

have prefixed length counter on winding machines to ensure uniform

diameter of packages on all drums.

- S. Kowsalya and S. Sivakumar

Textile Chemistry Division

Density of

cheese yarn

package

0.3408 g / cm3 or

340.8 g/l



May - June 2014

SITRA News 10

Studies on thermally conductive filamentincorporated hospital bed linens

Commercial hospital bed linens are made using either 100% cotton or

blend of polyester and cotton. The thermal comfort is decided by the

interaction between the clothing and the human body in terms of thermalsensations. Thermal comfort to the patient is an important quality

requirement for medical textiles products like hospital beddings,

curtains and apparels.

Thermal conductivity is an intrinsic property of a material that indicates

its ability to conduct heat. Thermal comfort is primarily related to the

efficient heat dissipation from a human body. Thermo physiological

comfort is affected by fibre type, yarn properties, fabric structure,

finishing treatments and clothing conditions. Fabrics made using straightfilament yarns remove heat rapidly by conduction method. These kind

of fabrics give a cool comfort to the wearer. When the fabric thickness

is increased, the thermal conductivity also gets increased.

SITRA has undertaken some studies on “Thermally conductive filament

incorporated hospital bed linens”. The studies were completed and

the major findings of the studies are given in this note.

Luxicool is a light elastic monofilament which can be used in weaving,

knitting and braiding. This filament conducts heat and cools the surface

of the fabric. It can be used to manufacture sportswear, work wear,

military wear, protective clothing, medical bandages, sports bandages,

linen and pillows (hospitals), shoes, spacer fabrics, etc.

Plain weave fabrics were produced at SITRA using luxicool filament

yarns with six different weft combinations. A total of 24 fabric samples

were produced with different combinations of fibre and yarn linear density

and pick arrangement (Table 1).



May - June 2014

SITRA News 11

T

a b l e

1

F a b r i c s a m p l e s p r o d u c e d u s i n g L u x i c o o l f i l a m e n t



May - June 2014

SITRA News 12

T a b l e

1

F a b r i c s a m p l e s p r o d u c

e d u s i n g L u x i c o o l f i l a m e n

t ( C o n t d . . . )

* C L – C o t t o n w i t h L u x i c o o l f i l a m e n t ; * * P / C L – P / C

f a b r i c w i t h L u x i c o o l f i l a m e n t



May - June 2014

SITRA News 13

The above 24 fabric samples were desized, scoured, mercerized and

bleached. The hospital bed linens woven using luxicool filaments were

evaluated for thermal conductivity.

Thermal conductivity

The thermal conductivity values of Luxicool incorporated hospital bed

linen fabrics are shown in Table 2.

Table 2 Thermal conductivity of Luxicool incorporated

hospital bed linen fabrics

* Cotton with Luxicool filament

** P/C with Luxicool filament

S.No . Fabric code Thermal conductivity ( X 10-3

W/(m.K))1. 14 Ne Cotton (Control sample) 36.30

2. 14 Ne – 1 CL* 42.90

3. 14 Ne – 2 CL 42.48

4. 14 Ne – 3 CL 38.56

5. 14 Ne – 4 CL 40.83

6. 14 Ne – 5 CL 37.48

7. 14 Ne P/C (Control sample) 27.14

8. 14 Ne – 1 P/CL** 31.01

9. 14 – 2 P/CL 29.25

10. 14 – 3 P/CL 27.86

11. 14 – 4 P/CL 30.23

12. 14 – 5 P/CL 28.27

13. 2/20 Cotton (Control sample) 38.95

14. 2/20 – 1 CL 45.95

15. 2/20 – 2 CL 43.59

16. 2/20 – 3 CL 42.87

17. 2/20 – 4 CL 44.70

18. 2/20 – 5 CL 43.20

19. 2/20 P/C (Control sample) 32.8720. 2/20 – 1 P/CL 35.31

21. 2/20 – 2 P/CL 34.31

22. 2/20 – 3 P/CL 33.14

23. 2/20 – 4 P/CL 35.07

24. 2/20 – 5 P/CL 34.17



May - June 2014

SITRA News 14

Thermal conductivity of luxicool incorporated bed linens is found to be

better by about 20% as compared to commercially available hospital

bed linens (Control sample). Higher values of thermal conductivity arebetter for fabrics meant for hospital bed linens. Relatively higher values

of thermal conductivity were observed for

i) 14 Ne cotton fabrics incorporated with Luxicool filament

(Pick arrangement: cotton – 2 picks

Polyester – 2 picks)

ii) 14 Ne p/c fabrics incorporated with Luxicool filament



iii) 2/20 Ne cotton fabrics incorporated with Luxicool filament



iv) 2/20 Ne p/c fabrics incorporated with Luxicool filament



Durability of Luxicool incorporated fabric samples

In order to assess the durability of Luxicool incorporated cotton and p/

c fabrics, the thermal conductivity of those fabrics was evaluated after

different number of washes and the results are given in Table 3.

It is discernible from the table that the thermal conductivity of Luxicool

incorporated cotton and P/C fabrics did not get affected much upto 30

washes or so.

DISTINGUISHED VISITOR

Smt. Kiran Soni Gupta I.A.S., Textiles Commisioner, MoT, GoI.



May - June 2014

SITRA News 15

- K.P.Chellamani, D.Veerasubramanian & G.Panneer selvan

Spinning Division & PLSC, Komarapalayam

Table 3 Thermal conductivity of treated cotton and p/c fabrics after

repeated launderings.



May - June 2014

SITRA News 16

Figure 1 Effect of yarn hairiness on fabric bending length

ARTIFICIAL NEURAL NETWORK

Series 7

Influence of yarn hairiness on handle properties of fabrics made using airjet yarns

In series 4, the development of an ANN model for the prediction of low

stress mechanical and surface properties of air jet yarns from process

variables was illustrated.

Using that neural network model, the effect of yarn hairiness on handle

properties of fabrics made using air jet yarn was studied and the results

are given in this note.

The changes in fabric properties due to changes in yarn hairiness

have been determined using the neural network model, assuming a

constant yarn linear density of 40s Ne, yarn flexural rigidity of 0.30 x

10 -3 cN cm2 / tex and yarn compressional energy of 2.30 x 10 -3 cN cm

/cm2 .

Figures 1, 2, 3 and 4 show the effect of yarn hairiness on fabric bending

length, kinetic frictional resistance, drape coefficient and compressional

energy.



May - June 2014

SITRA News 17Figure 4 Effect of yarn hairiness on fabric compressional energy

Figure 3 Effect of yarn hairiness on fabric drape coefficient

Figure 2 Effect of yarn hairiness on fabric to fabric kinetic frictional

resistance



May - June 2014

SITRA News 18

Higher values of yarn hairiness show a tendency, to increase the bending

length and kinetic frictional resistance of fabrics and to decrease the

compressional energy and drape coefficient of fabrics.

With an increase in yarn hairiness, fibre-to-fibre interlacements between

adjacent threads in the fabric will be more, which should make the

fabric more difficult to bend and also increase the kinetic frictional

resistance during yarn-over-yarn or fabric-over-fabric movement.

The greater extent of fibre-to-fibre interlacements between adjacent

threads in the fabric when yarns of higher hairiness are used also

makes the fabric more difficult to compress, which in turn reduces the

fabric compressional energy. With an increase in yarn hairiness, one

would also expect a decrease in effective yarn diameter, which in turn

would increase the shear angle. The relationship between yarn

diameter and shear angle, , is given by :

F – Rd

= tan - 1 ———

W

Where,

F is the force acting on the specimen (gf),

R is the shear experienced by the specimen (gf / cm),

d is the width of the specimen (or diameter of yarn ) (cm)

and

W is the tensioning weight applied on the specimen.

The combined influence of the two opposite factors, i.e, an increase in

bending length and increase in shear angle, resulted in the observed

reduction of drape coefficient with an increase in yarn hairiness.

To be continued…- K.P.Chellamani & M.K.Vittopa

Spinning Division



May - June 2014

SITRA News

Meetings attended

Dr. Prakash Vasudevan , Director, attended the third meeting of Sub-

Committee to identify HSN codes for Technical Textiles at the office of

the Textile Commissioner, Mumbai on 19th June, 2014.

MEDICAL TEXTILES - 11 S.no. Type of study No. of mills

Consultancy services offered by SITRA

during May - June 2014

1. Measures to reduce invisible loss 1

2. Machinery valuation 2

3. Techno-economic viability study 2

4. A study on doffing end breaks in ring frame 1

5. A study on improving yarn recovery 1

6. Weavers work assignment/loom efficiency study 1

7. Weft yarn performance study in Air-jet looms 108. Humidification system study 5

9. Energy audit 1

10. A method for precipitation of PVA in the

combined effluent 1

11. A study on bleaching of cotton terry towel

fabrics with peracetic acid 1

12. Feasibility of setting up a training centre 1

Besides the above major consultancy studies, SITRA also offered

solutions to eight adhoc problems in the area of spinning. Sixty oneinstruments were calibrated, 4 instruments were certified and 241

accessory samples were tested.

19



May - June 2014

SITRA News

Dr. K.P.Chellam ani, General Manager - Projects, attended the following

meetings:

- two Doctoral Committee meeting held at Karpagam University on

30th and 31st May 2014.

- conducted the viva-voce examination of Mr.P.Ganesan, Ph.D.

scholar of Anna University, Chennai at P.S.G.College of

Technology, Coimbatore on 23rd June 2014.

Mr. Sakthi vel Perumalsamy, Head - Centre of Excellence for Medical

Textiles, attended the 11th meeting of Project Approval Committee (PAC)

for Project Management & Monitoring Consultant (PMMC) of Technology

Mission on Technical Textiles (TMTT) on 10th June 2014 at the office of

the Textile Commissioner, Mumbai.

Papers published

1. J .Sreen ivasan and D.Shanm ug anandam “ Fibre to yarn

conversion cost - an analysis”, Indian Textile Journal, May 2014,

Volume 124, No. 8, pp. 29 – 33.

2. D.Rangana t han “Phytochemical analysis of Caralluma

Nilagiriana using GC – MS” Journal of Pharmacognosy and

Phytochemistry, May 2014, ISSN 2278-4136, Vol. 3, Issue 1, pp.

155-159.

3. K.P.Chellamani, D.Veerasub ramanian & M.K.Vittop a , “Inter-

relationship between Deviation rate (DR%) in yarn mass and

variations in yarn tensile characteristics and fabric appearance”,

Journal of the Textile Association, May – June 2014, Volume 74,No. 6, pp. 353 – 359.

4. K.P.Chellaman i, R.S.Vign esh Balaji and D.Veerasub ramanian

“Wound dressings: SITRA’s Contributions”, International Journal of

Emerging Technology & Advanced Engineering, June 2014, Volume

4, No. 6, pp. 177 – 184.

5. K.P.Chellaman i, R.S.Vignesh Balaji and D.Veerasub ramanian

“Quality Evaluation methods for textile substrates based wound20



May - June 2014

SITRA News

dressings”, International Journal of Emerging Technology & Advanced

Engineering, June 2014, Volume 4, No. 6, pp. 811 – 817.

Research Project review

Dr.K.P.Chellamani has reviewed a research project, on behalf of National

Research Development Corporation (NRDC), New Delhi for its suitability

for the Independence Day Prize Award.

New appointment

Mr. P.Prabu B.Tech. has been newly recruited as Scientific Officer inthe Liaison and Consultation Division.

Training programme on “Ratcheting quality in yarn manufacture”

A two-day programme focusing on the above topic was conducted at

SITRA during 16- 17, June 2014. Forty one technicians from 32 mills

attended the programme which covered topics like factors influencing

yarn elongation & yarn hairiness, Roller lapping in spinning, ways and

means of optimizing yarn quality with AFIS data & weak spot analysis,

results of various quality improvement studies at SITRA and the qualityrequirements of yarns expected by weavers & knitters.

Training programme on Low Voltage Switchgear selection and

maintenance

SITRA, in association with Larsen and Toubro Switchgear Training

Centre, Conoor has planned to organise a series of training programmes

on the selection and maintenance of low voltage switchgears. The

TRAINING

21



May - June 2014

SITRA News

programmes are being offered in 5 modules - i) Circuit breakers; ii)

Contactors & OLR; iii) HRC Fuses, Motor Starters & MPCBs; iv) VFDs,

MCBs, ELCBs, DBs; v) Fault level Calculations, Numerical Relays,BBT, MV Switch Gear. The first module on Circuit Breakers was held

on 30th June, 2014. Eighteen persons representing various mills and

other other industires participated in the programme which covered

topics like introduction to switchgears, selection and operation of

MCCBs, and operation and maintenance of ACBs. There was good

apreciation for the programme which, apart from covering theoretical

sessions, provided opportunity to the partcipants to have hands-on

working on model switchgears.

Jobbers Development Programme

At the request of a mill at Udumalpet, SITRA conducted a Jobbers

development Programme highlighting topics such as present textile

scenario, waste reduction, quality improvement etc. Twenty Jobbers

attended the programme.

Maintenance of Air-jet Weaving - Fitters training programme

To upgrade the skills of fitters towards managing new technologies in Air-jet weaving machines, an in-house training programme was

organised. Theoretical and hands-on practical training on the

mechanism of Air-jet weaving machines and their maintenance were

offered during the one week programme. Totally, 5 fitters took part in

the programme.

Fitters training programme for BC, MBC and DNC candidates

To upgrade the skills of fitters towards managing new technologies inshuttleless weaving machines, a training programme was organised.

Theoretical and hands-on practical training on the mechanism of hi-

tech weaving machines and their maintenance were offered during the

one month programme. Totally, 16 fitters took part in the programme.

Pre-employment training and retraining programmes for textile

workers

One out-station mill availed SITRA’s training services for their workers.22



May - June 2014

SITRA News

30 operatives were trained in one batch for the winder jobs in cone

winding. The training programme was conducted in Tamil.

Ancillary labour training

Retraining programmes were conducted to train 9 doffers in a spinning

mill at Coimbatore. The workers were trained to doff full cops and

replenish empty bobbins using both the hands while doffing ring frames.

In every programme, significant improvement was achieved in doffing

time and overall work practices.

55th Joint Technological Conference

The 55th Joint Technological Conference of ATIRA, BTRA, NITRA and

SITRA, conducted by NITRA, was held at PHD House, New Delhi on

10th May, 2014. Shri Sujit Gulathi, I.A.S, Joint Secretary, Ministry of

Textiles, Govt. of India inuguraated the Seminar and delivered the Key

Note Address. The following three papers were presented by SITRA

scientists at the conference which witnnesed a total of 12 papers from

all TRAs:

1. Impact of inter-mill variations in the techno-commercial

parameters on the financial performance of spinning mills -

N.K.Nagarajan & D.Shanmuganandam

2. Tensile & Tearing strength of woven fabrics - some studies -

K.P.Chellamani, D.Veerasubramanian & R.S.Vignesh Balaji

3. Yarn properties influencing fabric handle characteristics of

compact yarn fabrics - K.P.Chellamani, M.K.Vittopa &

R.Pasupathy

CONFERENCES AND SEMINARS

23



May - June 2014

SITRA News

FORTHCOMING TRAINING PROGRAMMESTraining programme on Low Voltage Switchgear

selection and maintenance

SITRA, in association with Larsen and Toubro Switchgear Training

Centre, Conoor is organising training programmes on the selection

and maintenance of low voltage switchgears in different modules. The

first two modules have been completed and following is the schedule

for rest of the three modules :

- HRC Fuses, Motor Starters & MPCBs - 14.08.2014

- VFDs, MCBs, ELCBs, DBs - 30.09.2014

- Fault level Calculations, Numerical

Relays, BBT & MV Switch Gear - 31.10.2014

For further details of the programme, kindly contact :

The Head, Engineering and Energy Division, SITRA.

Training of Trainers Programme

As part of the Integrated Skill Development Scheme (ISDS) of the

Ministry of Textiles, Govt. of India, SITRA is offering various

programmes (as detailed in another section of this SITRA News).

One programme offered under the scheme is “Training of Trainers”,

meant exclusively for Trainers / Jobbers / Master trainers / Maistries,

in spinning mills. Enhancing the skill of this group has become

essential in a scenario where continuous training to operatives is

the norm in the spinning industry. The programme shall be held atSITRA and mills can nominate one or two of the trainers/senior

operative(s) designated for training to attend the programme which

shall be of one month duration. Various topics like work methods of

operatives, scientific recruitment of operatives, records to be

maintained for operative’s assessment and training evaluation will

be covered during the programme.

Mills interested in nominating their personnel for the programme

may contact, “The Training Division”, SITRA.

24



May - June 2014

SITRA News

INFLUENCE OF TWIST DIRECTION ON TENSILE PROPERTIES OF

DOUBLE YARNS

Ramesh N. Narkhedkar, Melliand International, March 2014, Vol.

20, no. 1, pp 28-30

Twisting is a very essential process in the production of stable yarns,twines, cords and ropes. Twist is inserted to the yarn to hold the

constituent fibres together, thus giving enough strength to the yarn

with continuous length. It is worth mentioning that twist direction affects

the fabric’s properties. Figure 1 shows two identical twill weave fabrics

with warp yarns of different twist direction.

Figure 1 Two identical twill weave fabrics

Fabric A will be more lustrous than fabric B due to the fact that the

light reflected by fibres in the warp & weft is in the same direction.Fabric A will be softer as compared to fabric B due to the fact that in

fabric B the surface fibres on the warp & weft in the region of contact

are aligned in the same direction and they may ‘get stuck’ inside each

other and reduce the mobility of the intersection. However, in fabric A,

the surface fibres on the warp & weft are crossed over in the region of

contact and they can move easily. The freedom of movement at the

yarn intersections is the key for fabric softness.

25



May - June 2014

SITRA News

The results of a study reported in the article reveal that it is not just the

twist that plays a role in deciding the tensile properties of doubled

yarn but also the direction of doubling twist. The author has conducteda study using 100% cotton fibres and by producing 4 types of yarn

samples (30s Ne – Single & Doubled yarns), the details of which are

given in Table 1.

Table 1 Particulars of yarn samples produced

The major findings of the study, as reported in the article, are as follows:

― Single yarn of ‘Z’ twist is around 5.64% finer as compared to

single yarn of ‘S’ twist

― Doubled yarn of Z/Z twist is around 5.13% finer as compared todoubled yarn of S/Z twist.

― ‘S’ twisted single yarn exhibits around 15.36% higher lea strength

as compared to ‘Z’ twisted single yarn

― Z/Z doubled yarn shows around 6% higher lea strength in

comparison with that of S/Z doubled yarn. At the time of insertion

of ‘Z’ twist in two ‘S’ twisted single yarns, some amount of twist

gets removed from the single yarns due to reverse rotation of singleyarns during doubling, while in the case of Z/Z doubling, there is

no chance of twist removal. This is the reason why Z/Z doubled

yarns show relatively higher strength as compared to their S/Z

counter parts.

― The elongation values of Z/Z doubled yarns are also found to be

higher, as compared to S/Z doubled yarns by as much as 60% to

80%.

Sample Particulars

I Z twisted single yarn

II S twisted single yarnIII Two S twisted single yarns doubled by Z twist

IV Two Z twisted single yarns doubled by Z twist

26



May - June 2014

SITRA News

― Appropriate statistical analysis has shown that the differences in

strength & elongation values between the two types of doubled

yarns (Z/Z & S/Z) are statistically significant.

- R.S.Vignesh Balaji

Spinning Division

“EVALUATION OF FIBRE ORIENTATION IN FIBREWEBS”

Dipayan Das, S M Ishtiaque & Shivendra Yadav,

IJFTR, Vol. 39, March 2014, pp. 9-13.

It is well known that the orientation of fibres plays an important role in

deciding the quality of the fibrewebs as well as quality of end products.

In this study, the authors have evaluated the fibre orientation in fibreweb

by means of the Tracer fibre technique and Lindsley technique.

Tracer fibre technique

In this technique, a small proportion of coloured fibres is added to the

stock from which the web is prepared. On immersion in a liquid of the

same refractive index as that of the fibres, the web becomes almost

transparent and the path of the individual coloured fibres can then beclearly seen. Based on the measurement of angle of inclination of

several hundreds to thousands fibres from any of the axes of the web,

a histogram of fibre orientation angles is obtained. Further, an

appropriate analysis of the histogram provides some statistical

characteristic of fibre orientation in fibrewebs. This technique involves

a direct observation of the orientation of certain coloured fibres, present

in very small proportion among the white fibres.

Lindsley technique

In this technique, the estimation of fibre orientation in different fibre

materials is based on weighting of suitable combed-out and cut-out

fringes using a special apparatus. Fibre orientation is derived using

some empirical ratios of fringe weights, namely cutting ratio, combing

ratio and fibre orientation index.

In this study, the authors have used viscose staple fibres of 44 mm cut

length, with 1.5 denier linear density. Using viscose fibres the fibreweb27



May - June 2014

SITRA News

of 35 gsm was prepared by subsequent process of fibre in fibre opening

machine, roller carding machine and cross-lapping machine. The above

two techniques were used to find out the fibre orientation in fibreweb.

In tracer fibre technique, the fibre orientation in fibreweb is represented

as a parameter called “fibre orientation anisotropy” parameter. In

Lindsley technique, the fibre orientation in fibreweb is represented as

a parameter “fibre orientation index”.

The authors have concluded that the co-efficient of correlation between

the tracer fibre technique and Lindsley technique was very high.

- P.Sundaramoorthy

Weaving & Knitting Division

INFLUENCE OF POLYESTER FIBRE SHAPE AND SIZE ON THE

HAIRINESS AND SOME MECHANICAL PROPERTIES OF YARNS

R K Varshney, V K Kothari & Dhamija

Indian Journal of Fibre & Textile Research, March 2014,

Vol.39, pp. 24-32.

It is known that the fineness, length and strength of fibres used for spinning have a direct bearing on the yarn properties viz., tensile

modulus (strength), hairiness, etc. In this paper, the authors have made

an attempt to study the influence of fibre shape and size on the hairiness

and a few mechanical properties of polyester yarns. Determination of

the relative importance of these contributing variables along with level

of yarn twist has also been attempted by the authors to guide the

spinners in selecting the parameters that adequately meet end

requirements.

The possibility of designing a textile product is realized depending on

the way how the translation of fibre properties into its product takes

place and how they influence the yarn characteristics in general.

Variation in fibre form or geometry does influence this translation

efficiency by undergoing a change in its mechanical and surface

characteristics which ultimately effectuate a change in product structure

and properties.

28



May - June 2014

SITRA News

The authors have spun 27 yarn samples of 19.66 tex with different

polyester fibres varying in their cross-sectional shape (circular, trilobal,

scalloped and tetrakelion), length (44 mm and 38 mm) and fineness( 0.99, 1.33, 1.55, 1.66, 2.22 dtex). The yarns were also produced

with varying twist factors (27.26, 30.14 and 33.00). The influence of

experimental variables viz., fibre linear density, fibre cross-sectional

shape and twist has been assessed by them using linear regression

analysis at 5% level of significance.

The authors report the following findings:

1) Young’s modulus and bending stiffness of yarns increase withfibre linear density.

2) Bending rigidity reduces with increase in twist while the tensile

modulus exhibits an increasing trend.

3) The yarns made of tetrakelion shape fibres recorded the highest

tensile modulus followed by circular and lastly the scalloped

oval fibres (all of 1.66 dtex fibre fineness). Similarly, the tensile

modulus and flexural rigidity of yarns produced from trilobal fibres

(2.22 dtex) are higher than that of the yarns made of circular fibres (2.22 dtex).

4) Yarns made of coarser fibres exhibit more hairiness (S3 value).

5) Scalloped oval fibre manifests highest hairiness (S3 value) among

all analogous profiles in their yarns which is followed by tetrakelion

and circular fibres respectively. Hairiness of yarn made of trilobal

fibres is higher than that of the yarn spun from circular fibres.

6) Yarn hairiness tends to reduce as twist increases.

- S. Kowsalya & S. Sivakumar

Textile Chemistry Division

29



May - June 2014

SITRA News

BEE Mandatory Energy Audit for

Designated consumers

SITRA is pleased to inform members that the Accreditation

Advisory Committee of the Bureau of Energy Efficiency (BEE),

Ministry of power, Government of India has recommended and

recognized SITRA as an Accredited Energy Auditor to conduct

mandatory enery audits for deginated consumers. The details

are available on the website of BEE (www.beeeindia.nic.in) and

energy professional website (www.energymanagertraining.com).

Mills are aware that SITRA’s energy audits are already approved

by TNEB, GEDA, KSEB, BEE & PCRA. With a professional

setup comprising a BEE certified Energy Auditor and EnergyManager and multi-disciplinary specialists from Textile,

Mechanical and Electrical Engineering, and equipped with the

latest and sophisticated instruments, the energy audit team of

SITRA is well equipped and qualified to take up Mandatory energy

audits in mils that are conducted in accordance with the

regulations mandated by the Bureau of Energy Efficiency (Manner

and Intervals of Time for Conduct of Energy Audit) Regulations,

2010, vide their notification dt. 27.05.14 for Designated

Consumers (DC) in textile industry.

Mills desirous of availing the above service may send their enquiry

to: The Head - Engineering and Energy Division, SITRA.

New Service offered by SITRA !

30



May - June 2014

New Service offered by SITRA !

Lead auditor certificate in the ISO 50001:2011

Energy Management System (EnMs)

SITRA is offering a consultancy service to textile mills based on

Lead auditor certificate in the ISO 50001:2011 Energy

Management System (EnMS). SITRA‘s energy division has staff

well equipped and who have been certified as Lead Auditors by

Bureau Veritas (I) Ltd., Chennai to conduct audits leading to the

above certification. The scope of the consultancy service that is

being offered to the mills as follows:

> Gap Analysis.

> Energy Audit base line fixing.

> Documentation and manual preparation.

> Internal Audit.

> One day training programme to mill staff.

For furthur details regarding the service, kindly contact,

The Head,Engineering and Energy Division,

SITRA.

images pdfs may june2014

Documents