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PRODUCTIVITY AND COSTS

Assessment of machinery condition: A newapproach...... 1TECHNICAL NOTES

1. Confidence limits for the number of defectivecones..... 4

2. Cotton Stickiness

issues and solutions: Part 5........ 63. Water quality requirements for humidification

purpose in textile industry.... 10PROJECTS

Quality attributes of slub yarn - An investigation.... 13STAFF NEWS....20CONFERENCE AND SEMINARS..... 21

TRAINING...... 22ABSTRACTS....... 24

In this issue

SITRA News is a bi-monthly magazine, circulated to member mills.SITRA NEWS - May - June 2015, Vol. 56, No.3

2015, The South India Textile Research Association13/37, Avinashi Road, Coimbatore Aerodrome Post, Coimbatore - 641 014,Phone: 0422-2574367-9, 4215333, Fax: 0422-2571896, 4215300E-mail:[email protected], Website: www.sitra.org.in

This issue can also be downloaded from

SITRA.ORG.INscan code for web link


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SITRA News

May - June 2015

P R O D U C T I V I T YN D C O S T S

1

ASSESSMENT OF MACHINERY CONDITION: A NEW APPROACH

As we are aware, in any manufacturing industry, maintenance ofmachinery assumes a significance since machinery condition plays a vitalrole in deciding the productivity and quality of the products that aremanufactured by them. Spinning mills periodically carry out routine andpreventive maintenance activities by involving maintenance personnel likefitters, helpers, cleaners, etc. Some mills have the practice of checking thequality of maintenance works, immediately after their completion, mostlyby the QAD personnel.

SITRA has not come across any maintenance system with whichone can thoroughly check and record the condition of all the machines in aspinning mill including vital settings. Hence, SITRA has initiated a study onAssessment of machinery condition based on a comprehensive checklist

which would cover the entire machinery in a spinning mill includinghumidification plant, OHTC, AWES and YCP. The 'Checklist Manual' whichmay run into more than 100 pages, is under preparation. Recently,discussions were also held with senior managers and maintenancepersonnel of some leading spinning mills to elicit their views on the abovework and also their suggestions for shaping up the manual to be more userfriendly.

Salient features/outcome of the proposed study are given below:

Salient features:

- A comprehensive 'Checklist Manual' with guidelines forimplementation including rating will be brought out.

- Components will be grouped to indicate when they have to bechecked i.e. in the stopped condition or in the runningcondition.

- This activity would involve both subjective and objectiveassessments. Wherever needed, tools/gauges should be used.

- Condition of each and every component of various machinescan be rated by the mills. Tools and gauges that will be used in


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Increase work load by Changing machinery layout Imparting multi- skill training

Providing higher assignments Incorporating additional duties Enabling team work

SITRA News2

this exercise should also be assessed for their condition.

- The checklist would also cover the condition/functioning of

safety components such as machine covers, door limit switch,etc., so as to ensure safety of workers.

- Assessment must be carried out by persons other than regularmaintenance personnel, preferably by the QAD staff, eitherworking in the same mill or in the group mills, as the case maybe. But, the personnel concerned must be trained thoroughlyin carrying out this task. A minimum of 2 persons will berequired to carry out this task.

- Checking may be carried out periodically, preferably twice a

year.- A software will be prepared to enable mills analyse the

voluminous rating data quickly.

The proposed software would also enable mills to monitor thecondition of each and every machine periodically.

Benefits:

- Overall rating of machines either individually or as agroup/department-wise can be arrived at.

- Components which would require immediate attention(repair/renovation/replacement) can be listed out for eachmachine. This would be helpful for managements to takedecisions on modernising the machines.

- Mills can find out the machines that are responsible for thepoor yarn quality or low machine productivity (if any).

- Mills can have a periodical relook of the frequencies of variousmaintenance schedules. Introduction of new maintenanceschedules /activities may also be possible so as to ensure betterupkeep of the machines.

- Streamlining of the material flow for a given product-mix ie.allocation of suitable machines in the manufacturing linetowards achieving the required yarn quality/output will also bepossible.

- A suitable MIS report can be submitted to the topmanagement.

Sample checklistTo highlight the components that will be covered in the comprehensivechecklist, a sample checklist a particular machine (eg. comber) is given below:

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D.ShanmuganandamLiaison and Consultation Division

SITRA News3

May - June 2015

S.no.

Activity/components/parts

Checkmethod

Aspects to be seen/observed/checked Checkcondition

1.

Feed roller unit

*

Flutes

surface condition (sharpness/ flutedamage).

P

Feel surface for sharpness & bur. Off

*

Bottom stripper condition (rubberstiffness/edge damage).

P

Fold for stiffness/feel for edgedamage.

Off

*

Bearing condition (vibration and sound).

P

Rotate front & back feel for vibration&sound.

Off

* Bush condition (inner bore damage).

P

Shake up / down for bore play /wornout.

Off

*

Fleece

guide condition (inner surface/spring worn out).

P

Feel surface for bur/up/ down springaction.

Off

*

Feed roller ratchet RHS / LHS (wheel,

endbush & spring) condition.

P

Feel teeth thickness/springtension/play.

Off

2.

Top comb needles condition(edgesharpness/damage)

T

Check using Magnifier Lens. Off

* Top comb fixing bracket condition (loose /damaged).

P

Shake the bracket for play. Off

* Top comb fibre loading condition(accumulation at one place).

V

Feel for needle surface condition. Off

* Top comb fixing screw missing.

V

Check for damage or misaligned. Off

* Top comb locking spring tension.

P

Feel the expansion/ contraction ofspring.

Off

* Top comb sliding guide condition (groovedamage).

P

Insert top comb and check lockingaction.

Off

3.

Head stock unit.

*Indexing gears condition (teeth worn-out/keyway damage).

P

Rotate machine pulley and check gearplay worn-out.

Off

* Detaching roll gears condition (drive gearplay/damage).

P

Rotate machine pulley and check gearplay worn-out.

Off

* Check oil level in

head stock unit.

P

Check oil seen above all gears getimmersed.

Off

* Oil seal condition.

P

Check for oil leakage from seals. Off

* Vibration on head stock.

P

Feel vibration at machine runningcondition.

On

4.

Motor condition (vibration / sound).

P

Feel for vibration and sound in motorbody.

On

* Belt condition (cloth worn-out/ cracks). P Feel for cloth peel-off and cracks insides.

Off

* Belt tension checking. P Up/down for play checking. Off

* Both pulleys condition (surface/ edgedamage).

P Feel for surface cracks/ edge damage. Off

5. Brush roller unit.

* Brush diameter (bristles surface)condition.

T Check with calliper/ surfacesmoothness.

Off

*Brush shaft condition (seating worn-out/bearing condition).

P Shake shaft for play and vibrationwhile running.

Off

* Brush settings. T Check with calliper. Off * Brush holding Aluminium collars condition

(crack / worn-out).P Feel surface for cracks & damage. Off

* Brush drives pulley condition(edge/surface damage).

P Feel for cracks on surface/ edgedamage.

Off

* Belt condition (cloth worn-out/ cracks). P Feel for cloth peel-off and cracks insides.

Off

* Belt tension checking. P Up/down for play checking. Off

* Tension pulley surface condition(edge/stud damage).

P Feel surface/edge/shake stud for play. Off

Note: P: Physical; On: While machine is running,T: Tools/gauges;V: Visual;

Off: Idle or stopped condition


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TECHNICAL NOTEs

4 SITRA News

1. Confidence limits for the number of defective cones

In a mill producing 40s combed warp yarn, 50 full cones froma shifts production were checked for defects and classified asdefectives & non-defectives. The number of non-defective cones isfound to be 48.

The mill wants to know;

I) The 95% confidence limits for the non-defective cones.

ii) The 95% confidence limits for the defective cones.

Using sample data (statistic) to estimate the value (parameter)of the population is known as point estimate.

For eg., if 'n' is the sample size and 'r' is the number of non-defective cones in the sample, then r/n is the point-estimate of theproportion of non-defective cones in the population.

The objective of interval estimation is to find the limits withinwhich, with certain degrees of confidence, the actual proportion inthe population lies.

Cone defective in a lot follows the binomial distribution.

The number of non-defective cones in the sample is 48.

1) Confidence limits for the number of non-defective cones in thepopulation at 95% significance level

The confidence limits are arrived at using the following formula

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SITRA News5

The confidence limits for the number of non-defective conesat 95% significant level are 46 & 50. ie. In a sample of 50 cones, the

number of non-defective cones will vary between 46 and 50 atdifferent points of time.

2) Confidence limits for the per cent defectives at 95% significancelevel.

Point-estimate of per cent defectives = x 100 (PEPD)

Confidence limits for the per cent defectives at 90% significance level are,

No. of defective cones

Total no. of cones checked

= x 100 = 4.0 %250

= PEPD G 2 PEPD X (100 - PEPD)n

May - June 2015

= 4 24 96

50

ie., 0 and 9

Hence, the 95% confidence limits for per cent defectives are 0and 9.

Dr. K.P. Chellamani Spinning Division


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6 SITRA News

2. Cotton Stickiness : Issues and solutions- Part 5

Roller lapping is an important factor affecting theperformance of spinning which also influences to a great extent thetenters efficiency. Roller lapping, besides other process parameters,is caused by cotton stickiness. Generally, lapping tendency isexpressed as a Percentage Roller Laps with respect to the totalbreaks observed. This measure, per cent wraps, has severaldeficiencies for evaluating fibre / machinery performance. First, it istime-dependent and hence per cent wraps is frequently given as Percent-wraps in 'X' minutes. Second, time increment chosen variesfrom mill to mill and so results are not comparable. Third, once thetime increment has been chosen, the parameter becomesinsensitive to both high and low values.

Hence, with a view to overcome these deficiencies, a newmethod has been proposed. In this new method, the disadvantagesof conventional Percentage roller laps are overcome by expressing

the roller lapping tendency with respect to the time taken for alapping to occur after an end break. In this new method, the lappingtendency is expressed as Wrap Frequency (wraps/spindle minute).

The new method

The proposed method consists of choosing a set of 20adjacent spindles (ten adjacent roll pairs). To compare fibre andframe variables, it is better to use the same 20 spindles to minimize

positional variations around the frame. All twenty spindles are cutimmediately below the bottom roll with sharp scissors. A timer isstarted as the tenth spindle is cut. If all ends are not immediatelycaptured by the waste jet, it is necessary to repeat the procedureuntil all ends are in the jet at the start. The number of spindles thatwrap during the preceding time interval is recorded at 2, 4, 6, 8, 10,12 and 15 minutes. The procedure is repeated three times for a totalof sixty spindles cut. Then the wrap frequency (wraps / spindles min)

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SITRA News7

is calculated using the formula,

P = - [ In (N/S )] / T0

Where, T = Time of observation in minutes; N = Number of ends notwrapped at time T; S = Number of spindles cut at the beginning of0the test.

The method of calculating wrap frequency is illustrated inthe following 3 examples.

Example 1

s40 Karded yarn

No. of spindles cut at the beginning of the test (S ) = 200Time of observation (T) = 2 minNo. of ends not wrapped at the end of the test

period (N) = 15Then, wrap frequency (P) = - [ ln (15/20) ] / 2

2= 14 x 10wraps / spindle min

Example 2

s80 Karded yarn

No. of spindles cut at the beginning of the test (S ) = 200Time of observation (T) = 5 minNo. of ends not wrapped at the end of the testperiod (N) = 10Then, wrap frequency (P) = - [ ln (10/20) ] / 5

2

= 13.6 x 10wraps / spindle min

Example 3

s60 combed yarn

No. of spindles cut at the beginning of the test (S ) = 200Time of observation (T) = 6 min

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8 SITRA News

No. of ends not wrapped at the end of the testperiod (N) = 14

Then, wrap frequency (P) = - [ ln (14/20) ] / 6 2= 5.9 x 10wraps / spindle min

Verification of the proposed formula to assess roller lapping

Roller wrapping process follows a simple kinetic model. Change in ends inwaste jet = - (number of ends in waste jet) x (likelihood a given end willwrap in unit time) x (time increment) .(1)

i.e., in differential form, dN = - PN dt .(2)where,

N = number of ends not wrapped at time T;T = time in minutes;P = likelihood of one end in pneumafil wrapping in 1 minute (wrap

frequency) wraps / spindle minute.

Integrating this equation from zero time to T yields,

N T

dN / N = - P dt ............(3)S0 0

and

- In (N/S ) = PT ...(4)0

Where, S = number of spindles observed.0

Then, P = - [ In (N/S ) / T ] . (5)0

Where, P is the wrap frequency (wraps/spindle minute)

As per this equation, there is some characteristic wrapfrequency for a given fibre and process conditions which isindependent of the time of observation and number of spindlestaken for observation. This has been verified by SITRA by conductingtrials in member mills.

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SITRA News9

Wrap frequency Vs Time of observation

To check the influence of observation time on wrapfrequency, trials were conducted in 30s K, 60s K and 100s C bymaintaining the observation time at 15 minutes, 30 minutes and 45minutes (Number of spindles observed = 20). The results are shownin Figure 1.

- 2

W r a p

f r e q u e n c y

( W a r p

/ S p d

l . M i n ( x 1 0 )

Time of observation (Min.)

Figure 1 Wrap frequency Vs Time of observation

It can be seen that wrap frequency is practically independentof the time of observation.

Wrap frequency Vs Number of spindles observed

In this study, by maintaining the number of spindlesobserved at 10, 20 and 30, wrap frequency values were assessed(Time of observation = 15 minutes) and given in Figure 2. Here againWrap frequency is found to be independent of the number ofspindles taken for observation.

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- 2

W

r a p

f r e q u e n c y

( W a r p

/ S p d

l . M i n ( x 1 0 )

Time of observation (Min.)

Figure 2 Wrap frequency Vs No. of spindles studied

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

Spinning Division

3. Water quality requirements for humidification purpose in thetextile industry

Humidity and temperature play a very important role in themanufacturing of yarns and fabrics. Humidity control in textile millsis essential to maintain the product quality and reduceimperfections. Physical properties like dimensions, weight, tensilestrength, elastic recovery, electrical resistance, rigidity etc., of the

textile fibres are influenced by the moisture regain / moisturecontent of the fibres which in turn are affected by the humidity.

Moisture regain is the ratio of weight of moisture in thematerial to the bone dry weight of the material, expressed as apercentage while moisture content is the ratio of weight of moistureto the weight of material, expressed as a percentage.

10

May - June 2015

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Textile humidification system

A proper textile humidification systema maintains conducive atmosphere for proper mechanical

processing of fibresa maintains yarn strength, reduces lapping / breakage

problema dissipates static electricitya maintains product weight at appropriate levela reduces fly and micro dusta

provides free coolinga provides a cleaner and more comfortable workingenvironment for the human beings.

In textile mills, including spinning, weaving and processingsections, certain equipment / machines require circulation of waterthrough pipes. These include boiler, humidification plant, generators,multi-tubular heaters / coolers of the dyeing machines, etc. Highconcentration of dissolved salts, especially the hardness causing

calcium and magnesium ones, would affect the performance ofhumidification plants and other equipment mentioned abovesignificantly. The following are some of the important parameterswhich affect the performance of plants / processing:

a) Organic matter, turbidity and colour

Turbidity and colour are usually due to the presence of organicmatter in water and these detract the brightness of the bleached

products and purity of shade of the dyed ones. The organic matter,whether dissolved or suspended, breeds microorganisms that maydevelop mildew, fungi etc., which in turn would produce colouredspots, foul smell and even holes in the material.

b) Hardness

Hardness creates many undesirable effects in textiles. On heatingor coming in contact with alkalies, calcium and magnesium salts are

SITRA News11

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precipitated on pipes / fabrics as whitish carbonate and lowerswhiteness of the goods and depth of shade of the dyed goods and

mars purity and brightness of the hue. In package yarn dyeing, theprecipitated particles hinder free flow of liquor through the packagesand tend to cause uneven dyeing. The precipitated salts also impartharshness to the fibres. Excessive presence of these salts also causesuneven dyeing and necessitates addition of excessive sequesteringagents. With passage of time, the hardness producing salts in wateraccumulate to form a hard scale inside the pipes. The scale is a badconductor of heat and causes wastage of fuel in boilers and lowers

the efficiency of other equipment. Removal of the scale from insidethe tube is a time consuming and an expensive proposition and addsto the cost of processing.

c) Total Dissolved Solids

In addition to the hardness causing calcium and magnesiumsalts, water contains other dissolved salts that are mainly sodiumcations and chloride, sulphate and bicarbonate anions. These sodium

salts create certain complications like precipitation of dyes ofinherent low solubility. Presence of excessive amount of sodium ionsgives a damp and limp handle to the finished fabric due to theirtendency to hold water. The materials dyed in water having such saltslook dull and lack brightness. High TDS in the boiler feed water causesfoaming and carry over problems that lower efficiency of the boilersand also create difficulties in processing. Further, excessive sodiumions in boiler water / humidification plant feed water acceleratecorrosion of the iron plates due to their high electrical conductivity.Such waters also require more frequent blow downs that result infuel loss.

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13

PROJECTS

Quality attributes of slub yarns An investigation

Many spinning mills have started producing slub yarns as apart of diversification. The use of slub yarn enables the production offashionable woven or knitted fabrics with a natural look. Guidelinesfor the quality parameters of slub yarns like i) Deviation betweenmachine set & actual slub parameters for different slub patterns andii) Tensile characteristics are not available at present. Hence, SITRAhas conducted a study to develop database on the qualitycharacteristics of slub yarns.

Parameter Guideline value / permissible limitpH

7.0 - 8.5

Conductivity, S/cm 300-1250

Total Dissolved Solids (mg/l) 100-500

Total Hardness (mg/l)

100-400

Temporary Hardness (mg/l) 60-300

Iron as Fe (mg/l)

0-0.2

Manganese as Mn (mg/l) 0-0.2

Chlorides as Cl - (mg/l) 0-30

Silica as SiO2 (mg/l) 0-20

Residual Chlorine as Cl - (mg/l) 0-0.2

Calcium sulphate (mg/l) 0-100

Permissible water quality for humidification plants

-S. Kowsalya and S. Sivakumar

Textile Chemistry Division

May - June 2015

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14

Two different slub yarn systems were considered for thestudy. Slub yarn counts between 16s and 60s (warp as well as hosiery)

were included in the study. Some of the major findings of the studyare as follows.

1.0 Difference between machine set and actual slub parameters

Difference between machine set and actual slub parameterswas calculated for 50 different slub patterns in both the slub yarnsystems.

A slub pattern includes, (Figure 1)i) Slub lengthii) Slub diameter

andiii) Distance between slubs

Figure 1 Schematic representation of a slub yarn

Based on the results obtained, the difference betweenmachine set and actual slub parameters was arrived at and the sameis given in Table 1.

Table 1 Difference between machine set and actual slubparameters

S.No Slub parameter Difference between machine set & actual valuesSystem 1 System 2

1 Slub length (cm) 2 to 4% 9 to 19%2

Slub diameter (%)

2 to 6%

8 to 19%

3

Distance between slubs (cm)

2 to 3%

7 to 21%

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15

The difference between machine set and actual slubparameters is lower in system 1.

2.0 Factors influencing the extent of difference between machineset & actual slub parameters

The direction & extent of influence the different slubparameters exert on the difference between machine set & actualslub parameters are shown inTables 2, 3 and 4.

Table 2 Difference between machine set & actual slub length

for different levels of machine set slub lengths

S.No

System 1 System 2

Machine set

Slub length(cms)

Differencebetween machineset & Actual slub

length (%)

Machine SetSlub length

(cms)

Difference betweenmachine set &

Actual slub length(%)

1

2.8

3.92

3.0 19.002

3.5

3.32

3.5 17.873

4.0

3.41

4.0 16.014

4.5

3.20

4.5 14.775 5.0 3.13 5.0 13.326 5.5 3.02 5.5 11.647 6.0 2.67 6.0 10.228 7.0 2.12 7.0 9.159 8.5 1.98 8.5 9.06

With increase in machine set slub length, the differencebetween machine set and actual slub length tends to reduce in boththe slub yarn systems.

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16

Table 3 Difference between machine set & actual slub diameterfor different levels of machine set slub diameters.

S.No System 1 System 2

Machine set

Slub diameters

(%)

Difference betweenmachine set & Actual

slub diameter (%)

Machine setSlub diameter

(%)

Difference betweenmachine set & Actual

slub diameter (%)1 110 1.94 120 7.622 130 2.04 130 8.033 150

2.07

150 9.304 180

2.74

180 11.635 200 3.31 200 13.20

6 220 4.15 220 14.737 250 4.98 260 15.968 300 5.02 300 18.469 380 5.77 400 19.00

With increase in machine set slub dia, the differencebetween machine set & actual slub dia has a tendency to increase inboth the slub yarn systems.

Table 4 Difference between the machine set & actualDistance between the slubs for different levels of machine set

distance between slubs

S.No

System 1 System 2Machine set

Distance betweenslubs (cm)

Difference betweenmachine set & actual

distance betweenslubs

(%)

Machine setDistance between

slubs (cm)

Difference betweenmachine set & actual

distance betweenslubs (%)

1 7.0 3.09 7.0 21.432 11

2.80

10 19.103 18

2.68

18 18.284 25

2.58

25 17.555 30 2.41 30 15.106 40 2.11 40 11.507 45 2.05 51 10.768 52 2.00 63 8.969 59 1.96 76 7.08

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17

With increase in machine set Distance between slubs thedifference between the machine set and actual distance between

the slubs tend to decrease in both the slub yarn systems.

3.0 Tensile characteristics

In a given count, the strength of slub yarn is generally loweras compared to normal yarn by 10 to 20%. This strength difference isinfluenced by the presence of weak places in slub yarn. Massdecrease before and after a slub can lead to severe weak places inslub yarn. They are often related to the settings of the slub yarndevice. Therefore, this parameter is an important qualitycharacteristic of a slub yarn as it can lead to problems in the furtherprocessing of the yarn.

In order to study the effect of different slub parameters(which are determined by the setting of the slub yarn systems) onslub yarn tenacity, three sets of slub yarns were produced.

i) Slub yarns with different slub length, keeping slub diaand distance between slubs nearly constant

ii) Slub yarns with different distance between slubs,keeping other parameters more or less constant

iii) Slub yarns with different slub dia, keeping otherparameters constant.

3. 1 Influence of slub length on slub yarn RKM

With increase in slub length, slub yarn strength tends toreduce (Figure 2).

May - June 2015

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18

Figure 2 Slub lengh Vs Slub yarn RKM

With increase in slub length, the yarn segments with lowerlevel of twist in a given length will be relatively higher and this couldbe the possible reason for the reduction in slub yarn RKM.

3.2 Influence of Distance between the slubs on slub yarn RKM

With increase in the distance between the slubs, the slubyarn RKM goes up (Figure 3) and this is attributed to the less numberof interventions the slub yarn system has to make with the yarnforming process in a given length of yarn.

Figure 3 Distance between slubs Vs Slub yarn RKM

May - June 2015

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3.3 Influence of slub diameter on Slub yarn RKM

With increase in slub diameter, the slub yarn RKM shows atendency to come down, and the strength of association betweenthe two parameters is the highest (Figure 4).

Figure 4 Slub diameter Vs Slub yarn RKM

Hence, the strength difference between normal yarn andslub yarn depends on the length of slub, distance between the slubs

and slub diameter maintained by the mills.

K.P.Chellamani, M.K.Vittopa & V.Vijayajothi Spinning Division

Shri B.P. Pandey , AS & FA (Addl. Secretary & Financial Advisor),

Ministry of Textiles, Govt of India, Delhi.

Dr A.N.Desai , Director, BTRA

Prof. Dr Seeram Ramakrishna ,National University of Singapore.

Dr Maryam Yousefzadeh ,Amirkabir University of Technology, Iran.

Director of Center for Nanofibers& Nanotechnology,

Assistant Professor in TextileEngineering,

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1. Viscosity cup fabrication 32. Study of Knitting Machinery Maintenance Audit,

Productivity and Quality 13. Study on Humidification System & Noise level 24. ACS for humidification plants & compressors 25. Energy audit 36. Consultancy on Machinery valuation 1

7. Consultancy on Modernisation study 18.

Besides the above consultancy studies, SITRA also offered solutionsto 10 adhoc problems in the area of chemical testing, 77 instruments

were calibrated, 2 instruments were certified, 380 accessorysamples were tested and 4 samples were woven and knitted .

Study of capacity and water consumption of soft flowfabric dyeing machines 1

9. Qualification examination for 342 candidates for theselection of 16 shift supervisors in Tamilnadu Co.op 1Spinning mills

S.no. Type of study No. of mills

Consultancy services offered by SITRA

during May - June 2015

wsSTAFF

Meetings attended

Dr. Prakash Vasudevan, Director, attended the following meetings :

- Meeting to review the progress of Research & Development (R&D)scheme, Ministry of Textiles, New Delhi, 27th May, 2015.

- Review meeting of CoEs under the chairmanship of JS (R&D) and themeeting of the Project Approval Committee (PAC) under R&D scheme,Ministry of Textiles, New Delhi, 22nd June, 2015.

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- Meeting of Project Implementation Committee (PIC) and Meeting ofTechnical Committee uder Mini Mission - II, Office of the Textile

Commissioner, Mumbai, 22.06.2015

- Meeting of Bureau of Indian Standards, held at SITRA, Coimbatore,20.05.2015.

Nomination

Papers presented / Lectures given

Dr.K.P.Chellamani delivered the following lectures:

Dr.K.P.Chellamani has been retained by the Department of Science &Technology (DST), New Delhi as an expert the for evaluation of Projectproposals submitted to DST for sponsorship

1. Recent Developments in cotton and its processing in the'Foundation Day programme organized by Textile Association(India), South India Unit, at Sri Kasthuri Sreenivasan Art Gallery &

rdTextile Museum, Coimbatore on 23 May 2015.

2. Raw material Management & Yarn Quality at the ExecutiveTraining programme organized by Lakshmi Machine Works Ltd.,

thCoimbatore on 10 June 2015.

SITRA News21

May - June 2015

CONFERENCE

AND SEMINARS

International workshop on electrospinning andelectrospraying

The centre of excellence for Medical Textiles, SITRA conducted a two-day International Workshop on Electrospinning and electrosprayingduring 22nd and 23rd June, 2015.


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22 SITRA News

May - June 2015

ProfessorNational University of Singapore and Dr Maryam

Yousefzadeh, AmirkabirUniversity of Technology, Iran were the guided expert speakers whoconducted the workshop sessions.

Various topics like introduction to Nanofibers, their fabrication andproperties; characterization and different methods of nanofibersproduction; optimization of process parameters, the influence ofelectrical field, auxiliary electrodes and collectors in electrospinning;throughput enhancement using multi-needle, needless, chargeinjection; various possible structures (3D web, yarn) andmorphologies (Porous, Co-axial); application of nanofibres in filters,energy harvesting, sensors, protective clothing, biomedical devicesand composites, etc., were covered during the workshop. Practicaldemonstrations of the on Electrospinning setup was also part of theworkshop's proceedings.

The workshop also provided insights on the need of biocompatibleevaluation, global regulation on medical devices andbiocompatibility testing guidelines and requirements for a validbiocompatibility test report.

Forty participants from various institutions with research andindustry backgrounds attended the workshop.

Dr Seeram Ramakrishna, Director of Center for Nanofibers& Nanotechnology,

Assistant Professor in Textile Engineering,

Technical awareness programme .

At the request from M/s. National Textile Corporation., SITRAconducted a three day training programme for their newly recruited


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SITRA News23

May - June 2015

management trainees. The focus of the programme was to sensitizethem on various technical aspects involved in textiles namely,

present textile scenario, spinning process, fibre properties, yarnproperties, production and productivity aspects, basic maintenancein spinning mills, etc. Totally, 14 trainees attended the programme.

Training of Trainers

Textile sector Skill Council (TSC), a body created under the aegis of theNational Skill Development Council, New Delhi, has designated SITRAas one of the institutions to offer Training of Trainers Programmewhich is in fulfilment of the requirement for training providers (mills),affiliated to TSC, to train their workers. SITRA conducted a total of 9batches wherein 221 trainers from as many as 93 mills attended. Thefocus of the programme was to train the designated trainers toperform the role of training operatives in the mills. Various topicslike work methods in spinning mills, recruitment methodologies tobe adopted, assessing training needs in mills, periodical assessment

of trainees, maintenance, of records post-training assessment oftrainees, etc. were covered. The programme ensured that thecurriculum was in alignment with the National OccupationalStandards and Qualification Packs developed by TSC for the various

job roles for textile operations.

Pre-employment training and retraining programmes for textileworkers

Two out-station mills availed SITRA's training services for theirworkers. Fifty five operatives in spinning departments were trainedin 3 batches. The training programmes were conducted in Kannadaand Malayalam.


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DRAFTING FORCE MEASUREMENT AND ITS RELATION WITH BREAKDRAFT AND SHORT TERM SLIVER IRREGULARITYQasim Siddiqui & Chongwen YuIndian Journal of Fibre & Textile Research, Vol.39, December 2014,

pp.358-363

The interaction between dynamic drafting force and its variabilitywith break draft and short term irregularity of carded cotton sliver isdiscussed in this article. Drafting force data have been collected by theauthors from online draftometer, installed on break draft zone of cottondrawing frame as shown in Figure 1.

24 SITRA News

Figure 1 Schematic diagram of draftometer installed on break draft zonein drawframe

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V.Vijayajothi Spinning Division

SITRA News25

[1-computer system, 2-digital measurement controller, 3-weightingsensors, 4-arm, 5-pressure bar, 6-front rollers, 7-middle rollers, 8-back

rollers, 9-sliver and 10-shaft].

The results indicate that the dynamic drafting force initiallyincreases with increase in break draft upto a certain point, followed byattaining peak region with some fluctuations in drafting force. Afterreaching the maximum point, drafting force gradually decreases with anyfurther increase in break draft. The draft ratio at which the CV% of draftingforce begins to decrease and stabilize associates with high drafting force andit can be chosen as the optimum break draft in roller drafting process.

The authors report that higher values of drafting force correspondto low values of drafting force variability (CV%) and this provides bettersliver short term irregularity. Further studies to establish the relationbetween the variability (CV%) of drafting force and the dynamic behaviourof flowing fibre bundle with different top roller pressure are being carriedout be the authors.

MICRO CRYSTALLINE CELLULOSE POWDER FROM COTTON WASTE S K Agarwal & Nitin R Munde, Department of Textile Engineering, Akola, Spinning Textiles, Vol.8, Issue.6, Nov- Dec 2014, pp.62-67.

Microcrystalline cellulose is basically a cellulose that is derivedfrom high quality wood pulp or cotton linters and it can only be derived froma special grade of alpha cellulose. MCC is a versatile pharmaceutical andfood aid. It is used as an excipient in pharmaceutical formulation. MCC alsofinds its usage in wet granulation for better wicking action, as a better binder

and for favouring fast addition of granulation fluid. The other uses of MCCsare as stabilizer, emulsifier, smoothner, binder, cosmetics and suspender. In

tablets, Solka-Floc and Justfibre powdered cellulose act as an excipient. Ithas the unique ability to be compressed while providing effective binding,bulking and anti-caking properties. Cellulose fibre is free from contaminantsboth organic and inorganic. This makes it safe for ingestion in the humanbody. In this research work the authors have processed, hard waste fromtextile industry and made into MCC . Hard waste from spinning, weaving andfinishing industry were collected and acid hydrolysation was carried out to

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26 SITRA News

completely dissolve the cotton by using Hcl, it was then filtered, waterwashed, neutralized and dried. The dried sample was ground in a grinding

machine, to get the powdered form of MCC. Before using the MCC samplesin pharmaceutical industry (in tablet manufacturing) or in food industry (inice creams and bakery items), they were tested according to their respectiverequirements as per British pharmacopeia. The table given below shows the% yield of MCC from various textile wastes:

The authors report that today MCC is manufactured only fromwood pulp, soyabean husk and other sources. But manufacturing of MCCfrom cotton waste, which is a new one for the textile industry, would be

beneficial for the hosiery as well as woven textile manufacturing industrywhere huge amount of cotton hard waste and rags are generated.

In short, MCC made of cotton waste generates wealth from waste.

S.No.

Type ofsample

Vol. ofacid (ml)of 2.1 N

Weight ofsample

(g.)

Volumeof water(Litres)

Volume ofAcetone

(ml)

% ofNaOH

Weight ofMCC (g.)

%yield

1

Hard

waste

200 10

10

20 17.4 8.76 87.6

2

Hosierycuttings

200 10 10 20 17.4 9.12 91.2

3 Used cottonshirt waste

200 10 10 20 17.4 8.97 89.7

- S. Kowsalya and S. Sivakumar Textile Chemistry Division

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SITRA News27

May - June 2015

COMBO OFFER IN PHYSICAL TESTING OFFIBRE AND YARN

SITRA is offering various testing services to member

and non member textile mills. All the testings arecarried out as per international standards using state-

of-the-art testing equipment by qualified technicians.

Presently, SITRA is introducing fibre and yarn testing

in combination with various parameters as a package,

in addition to the regular individual tests. As part of this

new service, some of the essential parameters are

grouped as a package and tested at concessionalcharges. Details of the various packages and

concessional charges thereof can be viewed on our

SITRA website, lab.sitraonline.org. All mills are

requested to make use of this unique service of

SITRA.

Scan code for web link

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