SMEDA-JICA INDUSTRY SUPPORT PROGRAM
BEST PRACTICES MANUALKNITTING SECTOR
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Small and Medium Enterprises Development AuthorityMinistry of Industries and Production
Government of Pakistan
www.smeda.org.pk
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
ACKNOWLEDGEMENT
This manual has been prepared under the SMEDA–JICA Industry Support
Program. With the courtesy of Government of Japan and JICA (Japan
International Co-operation Agency), this program has been started in Pakistan for
the support of Textile Industry. The objective of this program is to provide
expertise, knowledge transfer and skill up-gradation for the enhancement of
productivity, efficiency and to give know how to local industry for better
management practices.
Senior Japanese Knitting Expert Mr. Takao MIYAZAKI offered his services as
Senior Volunteer for Knitting Sector of Pakistan for a period of two years. During
this period Mr. Takao MIYAZAKI has provided guidance / consultancy to
various industrial units.
This manual highlights the main areas where the guidance was provided in
different industrial units. This includes key findings, process details, important
recommendations / suggestions and recommended formats. It has been prepared
by Mr. Muhammad Ayaz & Mr. Adil Nazir Malik of Industry Support Cell,
SMEDA and reviewed and checked by Mr. Takao MIYAZAKI.
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
TABLE OF CONTENTS
AREAS IDENTIFIED AND RECOMMENDATIONS……………………………...…………11 Production Control .......................................................................................................... 1
1.1 Production Targets for Feeders Machine .......................................................... 11.2 Actual Production for Auto Striper Machine..................................................... 31.3 Knitting Program Chart .................................................................................... 41.4 Data Chart for Knitting Condition .................................................................... 41.5 Knitting Machines Daily Efficiency ................................................................. 51.6 Production Analysis Graph............................................................................... 61.7 Setting of RPM ................................................................................................ 71.8 Humidity and Temperature............................................................................... 71.9 Traceability of data........................................................................................... 7
2 Quality Control................................................................................................................ 82.1 Yarn Knotting .................................................................................................. 82.2 Handling and Storage of Fabric Roll................................................................. 82.3 Graphical Representation of Defects................................................................. 82.4 One Feeder Tube Knitting Machine.................................................................. 82.5 Yarn Tension.................................................................................................... 92.6 Yarn Eye Guides .............................................................................................. 92.7 Creel Pipe Position ........................................................................................... 92.8 Yarn Passage.................................................................................................. 102.9 MPF Tension Washers ................................................................................... 102.10 Damaged Paper Cones.................................................................................... 102.11 Slub Catcher Gauge........................................................................................ 102.12 Bar (Patta) Line.............................................................................................. 112.13 Press off Problem ........................................................................................... 112.14 Methods to Control Winder Lines .................................................................. 122.15 Oil Stains ....................................................................................................... 132.16 Spot Marks on Fabric Surface ........................................................................ 132.17 Double Stitch Problem ................................................................................... 132.18 Air Circulation System................................................................................... 142.19 Separating & Covering the Knitting Machine ................................................. 142.20 Method of Checking Greige Fabric GSM ....................................................... 14
2.20.1 Guidelines for Checking of GSM .................................................................. 152.21 Stitch Length of Fabric Sample ...................................................................... 152.22 Calibration of Round Meter............................................................................ 152.23 Measuring Actual Stitch Length ..................................................................... 152.24 Fabric Inspection............................................................................................ 162.25 Analysis of Inspection Sheet Machine Wise ................................................... 172.26 Yarn Inspection .............................................................................................. 182.27 Use of Compact Yarn..................................................................................... 182.28 Fabric Stability and Finished Width................................................................ 19
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
3 Machine Maintenance.................................................................................................... 203.1 Machine Maintenance Schedule ..................................................................... 20
3.1.1 Daily Maintenance ......................................................................................... 203.1.2 Weekly Maintenance...................................................................................... 213.1.3 Monthly Maintenance..................................................................................... 213.1.4 Bi-Annual Maintenance.................................................................................. 223.1.5 Annual Maintenance ...................................................................................... 223.1.6 Machine Overhauling ..................................................................................... 22
3.2 Lubrication..................................................................................................... 223.3 Sinker Timing Gauge ..................................................................................... 233.4 RPM Meters and Counter Meters ................................................................... 233.5 Machine Cleaning .......................................................................................... 233.6 Needle Life .................................................................................................... 243.7 Needle Break Data ......................................................................................... 243.8 Operator Responsibilities ............................................................................... 243.9 Analysis of Machine Stoppages...................................................................... 25
4 Cost Control .................................................................................................................. 264.1 Yarn Waste .................................................................................................... 264.2 Oil Leakage.................................................................................................... 264.3 One Operator for at least Two Machines ........................................................ 274.4 GSM Measurement ........................................................................................ 274.5 Individual Work Order Closing Report........................................................... 27
5 Fabric Development ...................................................................................................... 285.1 Stitch Length of Fabric Sample ...................................................................... 285.2 Determination of Count/ Denier of Given Yarn .............................................. 285.3 Actual consumption of yarn............................................................................ 295.4 Ratio of Cotton to Lycra Feed ........................................................................ 32
5.4.1 Finding the Percentage of Lycra ..................................................................... 325.5 Determination of Finish Fabric Gauge............................................................ 345.6 Setting of GSM in Greige Fabric .................................................................... 365.7 Knitting process ............................................................................................. 36
5.7.1 Analyze the Sample........................................................................................ 365.7.2 Development of Knitting Specification........................................................... 37
5.8 Knitting Construction and Layout Graph ........................................................ 375.9 Use of 1/1000 Gm Graduation Scale............................................................... 375.10 Knitting of 100 % Polyester or 100 % Lycra .................................................. 38
6 Useful Calculations........................................................................................................ 396.1 Calculating GSM of Swatch ........................................................................... 396.2 Calculating Length from Fabric Weight.......................................................... 406.3 Conversion Formulas for Cotton Count and Polyester Denier ......................... 406.4 Formula for Finding Gauge of the Yarn Count ............................................... 416.5 Calculations for Finding GSM........................................................................ 42
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
7 5 S (A Japanese Management Technique) ...................................................................... 447.1 How to Practice 5S......................................................................................... 45
7.1.1 Seiri ............................................................................................................... 457.1.2 Seiton............................................................................................................. 467.1.3 Seiso .............................................................................................................. 477.1.4 Seiketsu.......................................................................................................... 477.1.5 Shitsuke ......................................................................................................... 48
8 Fish Bone Theory .......................................................................................................... 498.1 Identify the Problem....................................................................................... 498.2 Work out the major factors involved............................................................... 498.3 Identify Possible Causes................................................................................. 508.4 Analysis your diagram.................................................................................... 50
9 Employee Participation & Training................................................................................ 519.1 Employee Training .................................................................................................... 51
ANNEXUREAnnex-I: Knitting Program Chart54Annex-II: Data Chart for Knitting ConditionsAnnex-III: Machine Counter StatusAnnex-IV: Production Analysis GraphAnnex-V: Machine Wise Inspection ReportAnnex-VI: Machine Maintenance ScheduleAnnex-VII: LubricationAnnex- VIII: Knitting Construction GraphAnnex-IX: Fish Bone Chart
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AREAS IDENTIFIED AND RECOMMENDATIONS
1 Production Control
1.1 Production Targets for Feeders Machine
Daily production targets should be defined on the basis of production capacity of
the machine. There is a 20 round method to measure the actual production capacity
of the knitting machines. In this method, the weight of the fabric produced for 20
rounds is taken and the production is calculated in a kilogram which is based at 100
percent efficiency by using the calculations explained below.
On the basis of this value, the actual efficiency of the machine and corresponding
production target may be defined.
The following is the procedure of the experiment that needs to be conducted on the
knitting machine:
Run the machine for 20 rounds and produce the fabric
Cut the 20 round fabric from the roll. If possible, a colored yarn can be used
to identify the fabric produced in 20 rounds
When cutting this fabric from the roll, handle it carefully
Now immediately place this fabric on the table in relaxed state and measure
the length and width of the fabric
Weigh the fabric
Using this data, calculates the production target as follows:
Fabric Width = (cm)= /100 (m) ……. (1)
Fabric Double Width = (1) × 2 (cm)
= /100 (m) ……. (2)
Length of Fabric produced in
the 20 rounds (cm) = /100 (m) ……..(3)
Weight of Fabric produced in 20 rounds = (gm) ...….. (4)
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Weight of One Round Length
(4) / No. of rounds = ...…... (5)
Meter Weight (4) / (3) (gram / meter ) = ...........(6)
GSM (6) / (2) = gram / meter 2 ...........(7)
Production Calculation (on 8 Hours basis):
Production for 100% Efficiency
= Machine R.P.M × 8 hours × 60 minutes x (5)
= (Fabric Weight in Grams)
= (Fabric Weight in Grams) / 1000
= (Fabric Weight in Kilo Grams) ……. (8)
This will be the weight of fabric produced at 100% efficiency at that particular
machine in 08 hrs. Similarly, the 100% production in 12 hrs or 24 hrs can be found.
Production @ 85% Efficiency
In order to set the production target for the knitting machine, multiply the 100%
production value with the desirable efficiency (in our case we took it 85 %)
= (8) x 0.85
= Kilo Grams ……… (9)
This (9) will be the production target based on the actual conditions.
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1.2 Actual Production for Auto Striper Machine
The actual production of Auto Striper machines is calculated in kilograms at 100
percent efficiency by using the calculations explained as below.
A = No. of Courses
B = No. of Courses
C = No. of Courses
D = No. of Courses
E = No. of Courses
Rounds of X Pattern Repeat
= (A+ B+C+D+E+……) × No. of Repeat
No. of Feeders
Fabric Width (cm) = (m) ……… (1)
Fabric Double Width (cm) = (m) ……… (2)
Length before cutting of X Pattern Repeats = (m) ……… (3)
Weight after cutting of X Pattern Repeats = (g) ……… (4)
Weight of One Round Length = (4) /Rounds of X Pattern Repeat … (5)
Meter Weight (4) / (3) (gram / meter) = ……… (6)
Production Calculation (on 8 Hours basis):
Production for 100% Efficiency
= Machine R.P.M × 8 hours × 60 minutes x (5)
= (Fabric Weight in Grams)
= (Fabric Weight in Grams) / 1000
= (Fabric Weight in Kilo Grams) ……… (8)
Production for 80% Efficiency
= (8) x 0.80
= Kilo Grams
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1.3 Knitting Program Chart
A knitting program chart should be attached on each machine. This will help to
provide complete view of the existing work order running on the machine (Format
is attached in the annexure-I).
The knitting program chart should include the following points:
Machine No.
Work Order No.
Machine Type
Machine Gauge /Dia
Machine RPM
Yarn Brand
Yarn Count
Fabric Type
Slitting Line Y/N
Stitch Length
GSM
1.4 Data Chart for Knitting Condition
Whenever, starting the new article it is appropriate to make a data chart (attached in
the annexure-II). This chart will help to have complete information about that
article and will be used for future reference. The implementation of this process will
reduce the wastage of time whenever a repeat order is requested. This will also
make the working easier and any problem that encountered during the production of
a repeat order can easily be solved.
Following information should be included in the said data sheet:
Machine Number
Design
Yarn Count
Stitch Length
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Round Meter
Tension
Sinker Timing / Needle Timing
Feeder Position.
IRO Tape.
Number of teeth of MPF tape
Greige GSM
Finish GSM
Problems encountered during production of the article
Possible solutions of problems
Swatch of the Fabric
1.5 Knitting Machines Daily Efficiency
For calculating the actual efficiency of machines and operators (shift wise & on
daily basis), a counter status check method is suggested (Format is attached in the
annexure-III). This counter status check is used to determine the actual production
shift wise. The following example illustrates the method to calculate the actual
efficiency:
For example:
I. M/C No. = 1
II. Work Order No. = 1685
III. RPM (Round Per Minute) = 20
IV. Total No. of Hours of One Shift = 8
V. Counters Required to Knit One Roll = 1900
VI. No. of Rolls Produced in One Shift = 3
VII. Total No. of Kilograms Produced in One Shift = 105
VIII. Counters Received from the Previous Shift = 1100
IX. Counters Forwarded to the Next Shift = 1000
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So, the Total actual rounds (counters) in the shift will be:
= (VI × V) + IX – VIII
= (3 × 1900) + 1000 – 1100 = 5600 Rounds
But as per the speed (rpm) 100% rounds should have been
= IV ×60 × 20 = 9600 Rounds
The Machine Efficiency can be found as follows:
= 100 x Actual Rounds /100% Rounds
= 100 × 5600 / 9600 = 58.33%
Following is the Format to calculate the efficiency of machine
M/C # W/O # RPM Weight Counters Rolls C. Rec C. Lft Ttl 1 Shift %
1 1685 20 105 1900 3 1100 1000 5600 9600 58.33
1.6 Production Analysis Graph
Graphical representation of the data is very useful to analyze and monitor the trend.
Therefore, production data should be represented graphically to analyze the
production trends. It indicates the low production values and helps to take
immediate actions for production improvement. (Graph is attached in the annexure-
IV).
This graphical representation of production data will help to effectively control the
production activities and to achieve the desired production targets.
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1.7 Setting of RPM
Every knitting entrepreneur wants to know the ideal speed of the knitting machine.
But it is very difficult to determine an ideal speed (rpm) even for particular design
and machine itself. It differs with the yarn quality as well as the machine condition.
Therefore the optimum speed of machine may be set after experiments.
1.8 Humidity and Temperature
The humidity and temperature in knitting department should be 60± 5 % and 25± 5
°C. However during dry season when the outside humidity level falls, humidification in the
department needs to be controlled more efficiently. Maintaining required humidity level
improves the performance of knitting machine without affecting the metallurgy of the
machines.
1.9 Traceability of data
If reports and filing system are not managed properly, it creates difficulty to monitor
the trends. Therefore it is necessary that the reports and filing system should be
managed properly.
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2 Quality Control
2.1 Yarn Knotting
Whenever yarn breaks or finished, it should be knotted instead of twisting as this is
normal practice used in industry. Because, in case of twisting it is likely that it may
open and may cause cut in the fabric. It is also one of the ways to reduce the cut in
the fabric.
During yarn knotting, the operator should use scissor / clippers for cutting the extra
knot edges. The extra knot edges should not be more than 5 mm in lengths.
2.2 Handling and Storage of Fabric Roll
Fabric roll should not be placed on the floor as it causes oil marks on the fabric. A
clean plastic sheet may be used to place the fabric roll on the floor. Also place
plastic sheet over the stored rolls to avoid accumulation of fluff on the fabric.
2.3 Graphical Representation of Defects
Graphical representation of fabric defects is very useful to analyze the quality.
Fabric defects should be represented graphically to easily monitor the quality and
take necessary corrective actions for each machine. Data recording in tabular form
is not easy to analyze whereas, graphical representation makes easier to view the
trend. Also, it is useful to find out the most recurrent faults.
2.4 One Feeder Tube Knitting Machine
The quality of incoming yarn can be easily monitored using one feeder tube knitting
machine. Another model of this machine is available with a creel for testing more
then one yarn cones automatically.
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2.5 Yarn Tension
Yarn Tension plays an important role in the knitting. It should be set properly at
start of each order and monitored as well. Yarn tension meter should be used to set
the yarn tension. The tension calculating formula for all type of yarns is:
Grams = 5315 / S (Count) × 20
This provides the starting guidelines for tension setting which can further be
adjusted by experimenting.
Variation in tension of yarn occurs due to improper winding. The following should
be taken care of:
MPF washer spring adjustment
Slow vibration of stopper
Presence of yarn eye guides (feeder, pipe, creel) on all machines
Replacement of damaged pipes
Even yarn wrapping on MPF (Main Pully Feeder)
2.6 Yarn Eye Guides
All yarn eye guides (feeder, pipe and creel) play an important roll in knitting
process. Missing yarn eye guides cause variation in yarn tension and high friction
hence affecting smooth flow of yarn. This also results in yarn breakage, knitting
holes and more fluff in the department. Therefore, missing eye guides must be
checked at regular intervals and replaced accordingly.
2.7 Creel Pipe Position
An improper position of creel pipe affects the yarn tension and thereby affecting
machine efficiency and increase fabric faults. Therefore, the creel pipe position
should be properly adjusted for smooth flow of yarn and damaged pipes should be
replaced with new ones. Also position of ring guides on creel should be at the
centre of paper cone tip.
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2.8 Yarn Passage
Yarn passage should be as smooth as possible. It should not touch any part of the
machine other than guides. Similarly, the correct passage of yarn should be
followed. If yarn touches any part of knitting machine other than guides, it will
increase the hairiness in yarn due to rubbings. It will also affect the yarn tension and
affects the machine efficiency and increase fabric faults (Knitting holes). To
overcome this problem, appropriate adjustment in the position of MPF should be
made.
2.9 MPF Tension Washers
MPF tension washers play an important role. As the name shows, MPF tension
washers control the yarn tension. If MPF tension washer is out of order or missing,
it will cause variation in yarn tension and high friction hence effecting smooth flow
of yarn. This also results in yarn breakage and fabric fault especially in fine yarn
count. Therefore, missing MPF tension washers must be checked at regular
intervals and replaced accordingly.
2.10 Damaged Paper Cones
If paper cones on the creels are damaged, it causes yarn breakage during unwinding
from these cones. It happened if the yarn suppliers is using paper cones of poor
quality and/or also care is not being taken during transportation and material
handling. The mill management must complaint the supplier if damaged cones are
received. Also, handling of yarn should be improved while loading / unloading as
well as placing on the knitting machine.
2.11 Slub Catcher Gauge
The following slub catchers are recommended to use:
0.4 mm slub catcher for 59/s and above count
0.6 mm slub catcher for 24/s to 39/s
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2.12 Bar (Patta) Line
Bar line is a major fault on the knitting machine. Bar line is basically appears due to
yarn tension variation or due to yarn quality. These are following steps for analysis
of bar line:
Take a piece of fabric from the defected portion
Marked length of 60 centimeters on both sides of fabric for analysis
Take out some yarns and find out the average length of yarns
If yarn which is creating bar line have same length as compare to other yarns.
This shows that the bar line may be appearing due to mixing yarn lot or using
different yarn count
If the stitch length of all yarns is not same then it will be the fault of yarn
tension
To control Patta in knitted fabric due to yarn tension variations, detect the feeders
where the Patta is visible and find out the respective feeders. Then keep on
changing the position of the cones on the creel till no such effect is visible.
2.13 Press off Problem
Press off is another problem being faced in knitting department. Press off problem
is basically a yarn breakage and it results due to the bad quality of yarn. During
knitting of fabric yarn break from feeder appears in the fabric as press off because it
broke after sensor.
To control the press off problem, the better quality yarn should be used and yarn
tension variation should be controlled on the knitting machine. The following points
will help to reduce the press off problem:
It should be ensured that passage of yarn is proper. It should pass from all
yarn eye guides and also should not touch with any other part on the knitting
machine
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All missing yarn eye guides should be checked at regular intervals and
replaced accordingly. Otherwise, yarns tension variations will result in press
off
The tension of all yarns should be set equal
The professional style of knotting should be adopted and operators should
use scissor for cutting extra knot edges
Fluff should be removed from machine and especially from feeders. Fluff in
feeders creates tension variation in yarn and increase the possibility of yarn
breakage
2.14 Methods to Control Winder Lines
Winder line is another problem of knitting. Following are the guidelines to control
the winder line:
Fastening woven fabric on the both ends of nip roller.
Ensuring minimum possible tension pressure on the fabric during winding.
Plaiting in a box.
Edge of the fabric from both sides should be made free by creating groove
on the nip roller
Slightly lower down the frame of fabric on knitting machine.
Changing the design of frame with Cadaratex frame (Fukuhara).
Slightly moving the winder line at inspection machine during inspection
The storage time of fabric should be as minimum as possible specially in
case of lycra fabric
Also, in dyeing department the fabric should not be stored for longer period
of time
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2.15 Oil Stains
Oil stains is the serious problem that affect the quality of fabric. One possible
reason is the use of excess oil than the actual requirement of the machine. This
excess oil spreads on the machine causing high accumulation of fluff at cylinder,
this fluff than goes under the needles and sinkers which creates oil stains in the
fabric. To control this problem, an appropriate amount of oil should be used.
Another possible reason is the frequent machine stoppages. When machine stops
frequently, the absorption of oil becomes high at the needles and sinker as
compared to the running condition of machine and that causes oil stains in the
fabric.
2.16 Spot Marks on Fabric Surface
Spot marks (Lycra, Polyester, Inlay yarn) on fabric surface are due to improper
adjustment of sinker timing. Proper setting of sinker timing with adjusting feeder
setting controls this problem. Yarn tension is also another reason and it should be
checked by tension meter and adjusted one by one on all feeders and if required
tuck tension should be increased.
2.17 Double Stitch Problem
The following are the precautions to avoid the double stitch problem in a particular
fabric:
Yarn passage must be smooth. Missing eye guides or improper yarn passage
causes yarn to vibrate
Control of yarn Tension. Tension meter should be used to control
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2.18 Air Circulation System
The overall cleaning condition on production floor affects fabric quality. To get
good quality fabric, floor cleaning and fluff suction system should be adequate. To
improve fluff suction system, increase the capacity of suction system or install air
conditioning system to maintain relative humidity of department as well as proper
suction of fluff. At least industrial vacuum cleaner should be used for fluff control.
2.19 Separating & Covering the Knitting Machine
The striper machines should be covered with polypropylene sheets to avoid fluff
accumulation from one machine to another. This will improve the fabric quality.
Similarly, the machines which are not in operation should be covered with
polypropylene sheets from top to bottom for avoiding the accumulation of fluff on it.
Due to less accumulation of fluff on the machine, the maintenance of machine will
be decreased and it will increase the machine life.
2.20 Method of Checking Greige Fabric GSM
It is general industry practice to check the greige GSM with GSM cutter. As in this
case, sample size taken is too small, therefore, GSM measured with GSM cutter
shows more variation. Large dia GSM cutter may be used to make the result more
accurate and reliable. The simple and accurate method to find the actual GSM of
fabric is based on three basic parameters i.e. fabric weight, length and width of the
fabric. It can be checked by producing the fabric / 20 round and then dividing the
weight of produced fabric by the area (length*width) of the fabric as in the section
1.1.
The actual GSM can be calculated as follows:
GSM = (6) / (2) gram / meter 2
GSM = g / m2
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2.20.1 Guidelines for Checking of GSM
The following are the further guidelines for checking the greige GSM:
Actual GSM of greige fabric (as explained above) should be measured at the
start of new article
Greige fabric roll should be cut as per counter meter reading on the
machine. In this practice, weight of each roll will be same. This is the
easiest way to check the GSM of each roll
2.21 Stitch Length of Fabric Sample
Stitch Length should be checked whenever starting the new order or problem arises.
The use of round meter for setting the stitch length is better. However, if it is not
available then, it may be checked manually. But in any case, it must be checked
when starting the new article or in case of any problem.
2.22 Calibration of Round Meter
Round meter is sometimes used for the setting of stitch length. It is advised that
round meter must be checked and calibrated for the correct setting. Check the stitch
length manually and compare the results with the round meter reading.
2.23 Measuring Actual Stitch Length
To find the actual stitch length, take a sample of fabric and mark 100 needles and
then take out at least three yarns each and measure the stitch length. Compare this
value with the round meter value.
Example:
We have a sample of fleece fabric produced on m/c having dia of 30 inch, Gauge 18
and total number of needles 1692. 100 needles were marked and then three knits,
tuck and inlay yarn each were taken out. Stitch length of knit, tuck and inlay was
measured. Mean value of the actual stitch length of knit, tuck and inlay was:
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Knit = 47 cm
Tuck = 41.3 cm
Inlay = 18.9 cm
The round meter reading on the same machine having Machine dia of 30 inch,
Gauge 18 and total number of needles 1692 was found to be:
Knit = 782
Tuck =683
Inlay =300
Converting round meter value to the /100 needle stitch length
Knit = 782/1692*100= 46.2 cm
Tuck =683/1692*100= 40.4 cm
Inlay = 300/1692*100=17.7 cm
Comparison
Comparing round meter reading with the actual readings revealed that:
Actual Knit stitch length is 1.7 % higher
Actual Tuck stitch length is 2.2 % higher
Actual Inlay stitch length is 3.8 % higher
Conclusion
The round meter should be checked at regular intervals to avoid any problem.
However, when variation in GSM arises check actual stitch length as well.
2.24 Fabric Inspection
It is worth considering a total inspection environment which can improve the
overall standard of the inspection department. The main action of a fabric
inspection machine is to unroll measure and re-roll the fabric, and to contribute to
an environment in which it can be inspected by an examiner.
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This requires the following characteristics:-
Suitable edge control to provide a finished roll of attractive appearance
Winding characteristics, which do not distort the fabric structure or
dimensions, which suggests tensionless wind up through, overfeed in the
case of stretch fabrics
Stopping and starting which will not disturb the roll, nor the fabric structure
nor its dimensions
Winding characteristics should be such that any form of handling by the
examiner is minimized
The machine should be simple to load and unload
Lighting should be controllable and of variable intensity, so that the most
critical faults may be detected most easily without loss of detection of less
critical faults
2.25 Analysis of Inspection Sheet Machine Wise
The analysis of defects should be done machine wise. This analysis will show the
individual record of every machine and the traceability of machine with too many
faults will become easier to find the root cause of problems. The collected data
should be analyzed and checked regularly, especially in case of same fabric
construction running on different machines for controlling the variation of faults.
Immediate actions should be taken after observing data for reducing rejection %
age. (Sheet is attached in the annexure-V).
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2.26 Yarn Inspection
Apart from checking the weight of yarn deliveries, following yarn properties may
be checked to ensure the quality of raw material:
Further Yarn Checks (1st order priority)
Count Tests on Staple Fiber Yarns: Check on count variability, within cones
and between deliveries: to be within tolerance of specification
Condition Checks: Check on incorrect condition
Yarn Unevenness (U %)
Further Yarn Checks (2nd order priority)
Yarn twist: On new deliveries and on demand for fault diagnosis. To be
within specified tolerance
Co-efficient of friction: Test and compare to specification
2.27 Use of Compact Yarn
Use of Compact spun yarn in knitting gives following advantages:
Less fly on the knitting machine
Knitting faults and interruptions are reduced and hence higher machine
efficiency
Smoother surface of Fabric as compare to Fabric made from conventional
ring spun yarn
More luster in fabric
Reduced pilling in the fabric
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2.28 Fabric Stability and Finished Width
Fabrics knitted on circular machines have a set number of wales, determined by the
knitting machine used, - its diameter and gauge (needles per unit length of cylinder
circumference). The fabric will be knitted from a certain yarn type and knitted loop
length, partly on economic grounds and partly to avoid being too dense or too light
a fabric.
There is a commercial incentive to finish fabric as wide and as long as possible. The
loop structure of knitted fabrics makes it possible to stretch these fabrics to an
appreciable extent. However, in the stretched state the forces on each loop are not
balanced, and so the fabric becomes unstable, giving it a tendency to revert to a
more natural, relaxed state during which an increase in fabric stitch density will
take place, together with a consequent reduction on area, i.e. shrinkage will always
occur. It is not possible to set a fabric at what are in effect unrealistic dimensions
and at the same time achieves a stable fabric. Therefore, certain diameters of
knitting machines are to be used (which is a must unless we are prepared
continually to replace existing machinery). Since the fabric will be knitted within
fairly narrow ranges of yarn type, count and loop length, then the fabric must be
finished as near as practical to its natural width and length and not over stretched, if
it is to be without excessive shrinkage in service (e.g. washing). In this state the
fabric will have fairly definite width and length dependent on the machine, yarn and
loop length used. Efficient lays should be planned on these dimensions, and not on
some predetermined ideal.
If shrinkage is not an important consideration, then extra width and length can be
considered. The fabric characteristics can be determined by calculations form the
fabric geometry and by trials, and the finished dimensions to be stipulated modified
accordingly. Unless these factors are fully understood, a satisfactory fabric
specification will not be possible.
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3 Machine Maintenance
3.1 Machine Maintenance Schedule
Maintenance of knitting machine is very important that affect the machine
efficiency, machine life and fabric quality. The management should prepare a
maintenance schedule and it should be followed strictly. The main parts of the
knitting machine should be checked with extreme care and responsibility. If the
knitting machine is too old, then maintenance became more important to avoid any
major breakdown. The following are the guidelines for machine maintenance
(Daily, Weekly, Monthly, Bi- Annually and Annually). Also maintenance schedule
is attached in the annexure-VI.
3.1.1 Daily Maintenance
The check points for daily maintenance are as follows:
Yarn feeding device and related parts:
Check yarn feeding device (MPF,IRO), Slipped-off, Loose or broken MPF
drive belt
Malfunction of clutch, IRO tape flipper, etc
Check MPF teeth
Clean fluff from MPF area
Remove fluff from tension washers
QAP (Quality Pulley): diameter, loose lock nut
Lubricators:
Oil level of mist lubricator
Check oil drop rate (should be 100-120 drops/ min)
Supply amount of compressed air
Check lubrication points for disconnection, leakage etc.
Check compressed air pressure
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Abnormal Noise:
Knitting elements (cam holders, sinker cap and dial cap)
Yarn feeding units and related parts (QAP, change gear box, drive tape, etc)
Frame (machine bed, take-up unit, motor drive, etc.)
Oil leakage:
Lubricator main body
Part underneath the bed
Oil amount in the oil sump bottle
Connection between oil mist pipes and nozzles
Part underneath the gear ring
3.1.2 Weekly Maintenance
The check points for weekly maintenance are mentioned here under:
Piping for lubrication oil and compressed air
Oil amount in the bed & gear box and make up if required
Check oil sump mist lubricator
Draining of water from the air compressor
Clean the lint fan
3.1.3 Monthly Maintenance
The check points for monthly maintenance are as follows:
Lint accumulation (Check for lint and clean.):
Lint in the control panel
Lint around lint fans and other areas
Lint in the motor cover
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Belt tension:
Check main drive motor belt tension
Check drive belt tension for yarn feeding device
3.1.4 Bi-Annual Maintenance
The check points for bi annual maintenance are mentioned here under:
Change the oil in gear box
Change the oil in needle bed
Remove the MPF pulleys and clean with kerosene oil
Machine cleaning should be checked very carefully for all parts
3.1.5 Annual Maintenance
The check points for annual maintenance are mentioned here under:
Change grease in fabric roll winder
Change grease in gear box of yarn feeding system
3.1.6 Machine Overhauling
Each knitting machine should be overhauled once a month. It is a guide line for
overhauling which is followed worldwide.
3.2 Lubrication
Shell Vexilla G or Mobil Vilocite CX 22 or Vickers CL22 or oil of same specs by
any other manufacturer is recommended as knitting oil for needles, sinkers and
cams. The selection of oil should be done keeping in view both the quality of the
fabric and the machine lubrication requirement. In fact it is a compromise between
machine safety and fabric safety. Very good washable knitting oil may not have
good lubrication property and vice versa.
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For machine bed, the Sell Tonna Oil S68 (viscosity @40c°55 to 70 CST) or
corresponding oil from any other manufacturer (format for selection of oil,
lubrication procedures and locations is attached in the annexure-VII).
3.3 Sinker Timing Gauge
Sinker timing reference points should be available on all machines for correct
setting of sinker timing gauges.
3.4 RPM Meters and Counter Meters
RPM meters and Counter meters on knitting machines should always be in working
conditions. The advantage of using these meters is the ease in daily production
calculations and minimum roll weight variation.
3.5 Machine Cleaning
The following are the guidelines for machine cleaning:
Each operator should individually take care of the proper machine cleaning
At each doff machine should be cleaned including the net cover
Waste cloth should be used for bed and underside cleaning
Machine cleaning with air pressure should be done only by operator
Cleaning of the creel should also be done
Those machines which are not in production should be covered to avoid
accumulation of fluff on the machine
Operator must be trained to follow the above guidelines and it should be made a
custom.
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3.6 Needle Life
The needle life depends upon various factors i.e. the quality of yarn being used and
the design of knitted fabric. The marks on needle buts are due to the uneven surface
of cams. Uneven surface cams should be buffed or new cams should be used to save
the life of needles.
After changing the complete set of needles with the new one, better condition
needles should be sorted out from old set of needles and should be used as
replacement whenever, needle brakes on any machine.
It is very difficult to determine an ideal needle life even for particular design and
machine. It differs with the yarn quality and machine condition. Polyester yarn
generally damages the needles more than cotton. Similarly it also depends upon the
GSM of the fabric to be produced. Keeping the all said factors in mind, the needles
should be used until at least 30000 to 50000 Kgs fabric is produced.
3.7 Needle Break Data
The record of broken needles and individual needles replaced on daily basis should
be prepared. Needle and sinker change schedule should also be maintained
properly. The concerned in-charge must ensure that all the data being collected
should be accurate.
3.8 Operator Responsibilities
Some basic responsibilities of knitting operators to ensure good quality and
production are as follows:
To minimize the faults on the same setting
The yarn path must be as start as possible and hindrance free
The yarn wrapping on the MPF (Main Pully Feeder) should be even
Feeders setting must be OK
Even smaller fault should not be ignored
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Daily machine maintenance checking
Fluff should not go inside the machine
Each operator must be allocated with space around its machine(s) and it
must be his responsibility to make sure the cleanliness of that area
Minimum stoppage of the machine
The healthy production should also come with quality
If operator sees any fault he must inform the concerned person
Operator should not start work in case of any noise in the machine
3.9 Analysis of Machine Stoppages
It is better to record the machine stoppages. This data then should be analyzed for
improvement in production. Use problem solving techniques explained in sections
to follow to analyze the data.
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4 Cost Control
4.1 Yarn Waste
It is observed that many baby cones (Pochey) are left over after the completion of
fabric. The yarn from one truck is not being mix used with yarn of other truck
(even yarn of same lot). The mills management normally does not mix the different
trucks of yarn in order to avoid the yarn variation. But this is the wastage of money.
The yarn from truck to truck can be used by confirmation of the same lot from
spinning mills. The yarn that is left over after the knitting of fabric (in the form of
Pochey) is not being analyzed from productive point of view. This yarn waste
(Pochey) should not be more than 10 kilograms/lot. If this waste will increase more
than 10 kilograms/lot then it should be analyzed that how to control this loss.
For example, there is requirement of five trucks of yarn against any order. The mills
management are performing yarn test sample five times to avoid yarn variation.
Each yarn test sample is not more then 5 kgs and after completion of fabric, the left
over yarn in the form of Pochey is 20 kgs of each truck. It means yarn used 25 kgs
for yarn test samples and 100 kgs for wastage (in the form of Pochey). This is totally
wastage of yarn. If the management confirms the yarn lot number then it will save
the 100 kgs of yarn which is being used in unnecessary areas. After the confirmation
of yarn lot, the yarn sample should be tested only one time. It means that in routine
practice, the extra yarn is being wasted four times. In the same way the yarn that is
left over after the knitting of fabric (in the form of Pochey) is too much.
4.2 Oil Leakage
The problem of oil leakage is due to the absence of oil seals and oil nozzles on
machines. If this problem continues, then this is not beneficial from cost point of
view as more consumption of oil. Also it affects the needle life and accumulates
fluff on the machine.
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4.3 One Operator for at least Two Machines
In routine practice, one operator handles only one machine. In this case the operator
has too much idle time. One operator should be used to handle at least two
machines because the machines are very close to each other in the knitting floor.
Therefore, the operators can easily handle two machines at a same time.
4.4 GSM Measurement
Normally in industry, GSM of greige fabric is being measured with GSM cutter;
this will produce holes in the fabric surface and also increase waste percentage.
GSM of greige fabric should be measured one time in the start of new article by 20
round method. If there are some doubts in GSM, then it is better to check fabric
stitch length. There is no need to check GSM of each roll. In this practice waste
percentage would be minimized. Any further adjustments in GSM should be made
on stitch length base rather than using GSM cutter.
4.5 Individual Work Order Closing Report
The analysis of rejection percentage should be performed by work order closing
report. This analysis will show the individual record of every work order. It makes
easier to trace out the root cause of rejection. The manager should be checked the
work order report regularly.
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5 Fabric Development
5.1 Stitch Length of Fabric Sample
The following is the method of checking stitch length manually:
Take a small piece of fabric (40-50 cm in length)
Mark length of hundred wales on both sides of fabric
Take out ten threads and find out the average length of the threads. This will
be the stitch length of that sample
Note: If fabric sample size is too small, then mark length of thirty wales on both
sides of fabric. Take out three threads and find out the average length of these
threads.
5.2 Determination of Count/ Denier of Given Yarn
The method to find out the Denier / Count value of the yarns in a fabric sample is as
follows:
Put two cut marks at certain distance (30-40 cm) on the fabric sample
Take out different yarns (Count / type) by undoing the knitted structure
Take out at least 10 yarns for each count or type of yarn
Measure the length of each count or type of yarn and add them to get the
total length of yarn (in m) for each count
Now determine the weight of the yarns count wise
Calculate the denier value using the formula:
Denier value = Weight of the yarn in gram x 9000Length of yarn in meters
For determining the corresponding count value, the denier value can be
converted to Count using the following conversion formula:
Count= 5315 / Denier
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Example:
Suppose undoing of the knitted fabric provided the following observations:
Type of yarn = 2 (i.e. 2 cotton yarn & 1 Lycra)
No of yarn taken out for each type of yarn= 30
Length of each yarn = 71.23 cm
Total length of Cotton yarn = 30 x 71.23 cm = 2136.9 cm= 21.369 m
Weight of Cotton yarn using weighing balance with a least count of 0.001 g = 0.31g
Thus Denier value of the Cotton yarn will be:
Denier value = Weight of the yarn in gram x 9000
Length of yarn in meters
Denier value = 0.31 x 9000 = 130.56 denier (approximately)
21.369
Converting it into count,
Count = 5315 / Denier
= 5315 / 130.56
= 40.7 Count
= 40/s (approx.)
5.3 Actual consumption of yarn
In planning a certain order, knowing the consumption of yarn is important so that,
required quantity of yarn can be purchased. It becomes more important when we are
using different yarn in the same fabric.
If we have the three end fleece with one type of yarn in Knit and Tuck, and another
yarn the in Loop. To calculate the actual yarn consumption or yarn mixing ratio
following is the procedure to be followed:
Take the a small piece of fabric
Find out the weight of sample fabric
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then take out the loop yarn from sample fabric and find out the weight of
Loop yarn
The subtraction of loop yarn weight from sample fabric will give the weight
of knit & tuck yarn
Now the consumption of yarn or mixing ratio can be calculated
EXAMPLE:
There are two methods of calculating Consumption of Yarn in 3 End Fleece.
Suppose we have the three end fleece fabric with 30/s of yarn in Knit and Tuck and
16/s yarn the in Loop.
1st method: When Stitch length of knit and tuck are same and loop is deferent:
KNIT TUCK LOOP
Cotton Cotton Cotton
Count 30 30 16
Stitch length 22 cm 20.5 cm 7.5 cm
Knit and Tuck the count is same, so added Knit and Tuck
= 22 + 20.5
= 42.5 cm = 7.5 cm
= 42.5 × 1 / 30 = 7.5 × 1 / 16
A = 1.417 B = 0.469
Total= A + B = 1.417 + 0.469
=1.886
% of 30/s % of 16/s
= 1.417 / 1.886 × 100 = 0.469 / 1.886 × 100
30/ Ѕ = 75.1% 16 /Ѕ = 24.9%
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For 50,000 Kg fabric quantity of yarn required (including 2 % knitting loss)
A= 30/s = 50000 × 1.02 × 0.751 = 38301 kg
B = 16/s=50000 × 1.02 × 0.249 = 12699 kg
2nd method: When Stitch length of knit, tuck and loop are deferent:
KNIT TUCK LOOP
Cotton Polyester Cotton
Count 30 / Ѕ 45 d 16 / Ѕ
Stitch length 22 cm 20.5 cm 7.5 cm
To convert count into denier using formula
D = 5315 / S
5315 / 30 45d 5315 / 16
177.2 d 45 d 332.2 d
Multiplying to stitch length
177.2 × 22 45×20.5 332.2 × 7.5
3898.4 + 922.5 + 2491.5
Total = 7312.4
3898.4 / 7312.4 922.5/ 7312.4 2491.5 / 7312.4
0.533 × 100 0.126 × 100 0.341×100
53. 3 % 12.6% 34.1%
Consumption of yarn
A = Cotton (30 s) 53.3%
B = Polyester (45 d) 12.6%
C = Cotton (16 s) 34.1%
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For 50,000 Kg fabric quantity of yarn required (including 2 % knitting loss)
A = 50000 × 1.02 × 0.533 = 27183 kg
B = 50000 × 1.02 × 0.126 = 6426 kg
C = 50000 × 1.02 × 0.341 = 17391 kg
5.4 Ratio of Cotton to Lycra Feed
It is common practice in the industry that Lycra percentage is always set on the
machine by hit and trial method which is not an efficient way. Setting the exact
percentage of Lycra is difficult in this way. If we have to set the 3 percent of Lycra
than, by hit and trail it is possible that, this value may be set to somewhat higher. In
case of a large order a small increase in this percentage will increase the cost of
production as Lycra is very costly. In order to set the Lycra percentage in more
efficient way the following method is very useful.
5.4.1 Finding the Percentage of Lycra
If we have a sample of Lycra knitted fabric and wants to produce that fabric with
same percentage of Lycra. For this purpose we have to calculate the ratio of the
feed speed of cotton and Lycra to determine how slower the Lycra must be fed as
compared to cotton yarn so that we get same percentage of Lycra in the fabric. The
following is the procedure:
Put two cut marks at certain distance (30-40 cm) on the fabric sample
Take out different yarns (count / type) by undoing the knitted structure
Take out at least 10 yarns for each count or type of yarn
Measure the length of each count or type of yarn and add them to get the
total length of yarn in meters for each count
Now determine the weight of the yarns count wise
From weight find out the Lycra percentage
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Calculate the denier value of cotton yarn using the formula:
Denier value = Weight of Cotton yarn (g) × 9000 Length of Cotton yarn (m)
Now find out the Denier value of Lycra by using following formula:
Denier of Lycra = Weight of Lycra × Cotton Denier Weight of Cotton
Find the Lycra Feed ratio using following formula:
Lycra Feed Ratio = Calculated Denier Actual Denier to be used
Example:
Suppose we have a Lycra based Fabric sample. Un-roving of the knitted fabric
provided the following observations:
Type of yarn = 2
Feed of yarn = 2 cotton yarn & 1 Lycra
No of yarn taken out for each type of yarn= 15
Length of each yarn = 110.4 cm
Total length of Cotton yarn = 110.4 x 15x 2= 3312 cm = 33.12 m
Weight of 30 Cotton yarns = 0.66 gm
Weight of Lycra = 0.02 gm
Cotton Yarn Denier = 9000*0.66/33.12= 179.35
Cotton Count = 5315/179.35 =29.6 30/s
Lycra Denier = 9000*0.02/ (15*1.104) =10.87
If we have to use 40 D Lycra than, the ratio of feed speed should be
Lycra Feed Ratio = 40/10.87 = 3.68
i.e. Lycra should be fed at 3.68 times slower in speed than cotton. If we adjust the
Lycra feed according to this calculated value then we will get the same percentage
of Lycra in the fabric.
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Consumption of Yarn
% age of Cotton = Cotton Weight / (Lycra Weight + Cotton Weight)
= 0.66 / 0.68 ×100
= 97.06 %
Lycra % = Lycra Weight / (Lycra Weight + Cotton Weight)
= 0.02/0.068*100
= 2.94 %
5.5 Determination of Finish Fabric Gauge
Sometimes, we may receive the finish fabric from the customer to knit. In that case,
the following is the method of finding the gauge of the machine used to produce
that fabric:
In case of full width finish fabric
If we have full width finish fabric then:
Find the total width of fabric
Count 100 wales and measure the corresponding length and find the wales /
length
Calculate the number of needles using following formula:
Total no. of Needles / Total Width of Fabric in cm = Wales/ cm
Find the Dia of the machine keeping in view the following guidelines:
Note: This table is based on the experience. So, it is for reference only to start with.
Total Width of Fabric
(cm)
Dia of the Machine
(inch)
120 24
130 26
140 28
150 30
165 32
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Calculate the gauge of the machine used to produce that fabric by using
following formula:
Gauge = Total No. of Needles / (п × Dia of the machine)
Example:
Measured Width of the fabric = 75.5 cm
Total Width of the fabric = 75.5 × 2 =151 cm
Length of 100 wales = 8 cm
Suppose X is the total number of needles.
Therefore,
X/151 = 100/8
X = 1887.5
Referring to the above table the dia of the machine comes out to be 30 inch.
Now,
Gauge = 1887.5 / (3.143 × 30)
Gauge = 20
In Case of Swatch of Finish Fabric
Sometimes, we do not have full width finish fabric instead; we receive a swatch of
finish fabric from the buyer. In that case to find the gauge the following method
should be followed:
Assume the total width of the fabric or if factory is producing the fabric for
its garment division then, get the width of the fabric from cutting
department who will provide the same on the basis of the garment to be
made from that fabric
Count 100 wales and measure the corresponding length or if swatch is too
small count Wales / inch
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Calculate the total number of needles using following formula:
Total No. of Needles / Total Width of Fabric in cm = Wales / cm
OR
Total No. of Needles / Total Width of Fabric in inches = Wales/ inch
Find the dia of the machine keeping in the view the above table
Calculate the gauge of the machine by using following formula:
Gauge = Total No. of Needles / (п × Dia of the machine)
5.6 Setting of GSM in Greige Fabric
There is no formula for setting GSM of greige fabric with respect to finished fabric.
However, as a starting point GSM in greige fabric may be adjusted at
approximately 55 to 60 digits less than the GSM of finish fabric. But it requires
experimentation to get the final result.
5.7 Knitting process
The following are the steps to follow for analyzing a particular knit sample and to
reproduce it:
5.7.1 Analyze the Sample
The following are the steps to analyze a particular knitted fabric sample to be
produce:
identify types of yarns in sample
count courses and wales per cm in each structure
determine stitch length and counts of yarns used by unroving
estimate likely gauge of machine on which sample knitted
determine the design, pattern repeat
check GSM
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5.7.2 Development of Knitting Specification
select nearest suitable commercial yarn available and gauge of machine to
be used for adaptation to reproduce sample
knit swatch for each structure at calculated course length based on
experience of machine settings
check course length by un-roving or marked yarn method
adjust until correct (tolerance of +- 2% suggested)
record settings (on knitting condition data chart explained earlier) e.g. input
tension, weight of take down, knock over depth
knit sample panels
check and record complete panels for appearance, dimensions and weight
on the basis on data recorded set up other machines similarly
check for course length and adjust necessary
N.B. if (c) has been correctly carried out machine adjustment should not be
required.
5.8 Knitting Construction and Layout Graph
The knitting construction and layout graph sheets for single knit, rib and interlock
are attached in the annexure-VIII. This will help to understand the construction of
fabric. Graphs should be made and maintained for each type of fabric as a future
reference.
5.9 Use of 1/1000 Gm Graduation Scale
It is better to have the weighing scale of 1/1000 gm least count. It is very useful
whenever finding count of yarn, % of any particular yarn in the fabric or GSM of
fabric. In these cases, a great accuracy of weight is required for correct results.
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5.10 Knitting of 100 % Polyester or 100 % Lycra
When 100 % Polyester yarn or 100 % Lycra yarn is used for knitting fabric then it
is necessary to arrange a new set of needles on knitting machine. It is impossible to
knit fabric with existing settings and needles of knitting machine. Otherwise, needle
line appears in fabric. First of all a small sample of fabric should be prepared and
after processing its conditions should be checked carefully. If there is some severe
needle marks in fabric then immediate action should be taken for removing needle
marks. In case of 100 % Polyester knitting, management should be more conscious
about yarn tension. Otherwise, when Polyester yarn is broken; it is very difficult to
watch with naked eye during knitting or in running condition.
The coordination between knitting and dyeing department is very essential for
producing this type of fabric. The management should first try to produce Polyester
Cotton blend fabric. After getting successful results in knitted blend fabric,
management should try for knitting of 100 % Polyester or 100 % Lycra fabric.
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6 Useful Calculations
6.1 Calculating GSM of Swatch
The method to calculate the GSM of swatch using following formula:
GSM = Weight
100×100 Width × Length
For example:
3cm
5cm
Width = 3(cm)
Length = 5(cm)
Weight = 0.37g
GSM = 0.37
100×100 3 × 5
GSM = 0.0246 × 10000
GSM = 246.7
0.37g
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6.2 Calculating Length from Fabric Weight
Calculation formula for converting Kilograms of fabric to Meters is as follows:
Since,
GSM = Weight (g)
Length (m) × Width (m)
Therefore,
Length (in meter) = Weight (g)
GSM × Width (m)
6.3 Conversion Formulas for Cotton Count and Polyester Denier
S = 5315 / D
OR
D = 5315 / S
Where,
S = English Count
D= Denier
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6.4 Formula for Finding Gauge of the Yarn Count
If,
S = Cotton Count
G = Gauge
C = Metric Count
Then,
G= K √ C
OR
G² = C÷ K²
Since, C = S × 1.6936
G² = (Sx1.6936 ÷ K²)
G²= S × (1.6936 × K²)
Where K= Constant
For Single Needle K= 3.5
For Double Needles K = 2.5
Example:
For S = 20 s K = 3.5
Using above relation
G = 20.36 → 20 G
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6.5 Calculations for Finding GSM
The following is the method for finding the GSM with respect to stitch length.
When we know the value of Stitch Length, Dia, Gauge, Finish Width and Yarn
Count then, we can find the GSM.
If,
Dia in Inches = D
Gauge = G
Count = S
Number of Needles = D × 3.14 × G
Fabric Width in Inches = F
= F × 2.54
Wale = D ×3.14 × G
F × 0.0254
= 123.6 × G × D
F
Course = D ×3.14 × G × 5
F × 0.0254 4
= D × G × 154.53
F
One Loop Length L (m) = Stitch Length
No. of Wales
Yarn Length = Wale × Course × L
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= 123.6 × G × D ×D × G × 154.53 × L
F × F
= 19099.9 × G² × D² × L
F²
W (GSM) = 5315 × 19099.9 × G² × D²×L
S F²× 9000
= 11279.6 × G² × D²×L
F²× S
For Example
Dia = 30
Gauge = 20
Count = 22
Number of Needles = 30 × 3.14 × 20 = 1884 ↔ 1860
Fabric Width = 62" = 62 × 2.54 = 157.48 cm = 1.5748 m
Wale = 1860 ÷ 1.5748 m = 1181
Course = 1181 × 5 = 1476
4One Loop Length = 61.5 cm = 0.003075 m
200 (wale)
Yarn Length = 1181 × 1476 × 0.003075 = 5360.2 m
D = 9000 × W L
W = D × L 9000
= 5315 × 5360.2 9000 × 22
W (GSM) = 143.9 g / m²
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7 5 S (A Japanese Management Technique)
5S is a Japanese quality management concept that was introduced and advised to
practice in the factories for creating a high quality, a highly productive and a safe
working environment. 5S is a simple and systematic five step Japanese approach for
clean, neat, properly organized workplace through employee’s initiatives. It should
be gradually adopted and than it will become the habit. It is an acronym for five
Japanese words Seiri, Seiton, Seiso, Seiketsu, and Shitsuke.
The meaning of 5S is explained as follows:
Seiri: To sort and throw away unnecessary items
Seiton: A place for everything and every thing in its place
Seiso: Maintain high standards of Cleanliness
Seiketsu: Standardize all procedures
Shitsuke: Train and maintain Discipline
5S can provide a solid foundation for other productivity and quality programs such
as Total Quality Management, Total Productive Maintenance, Waste Reduction and
Just in Time Production and Inventory Management. 5S reduces the gap between
the top and bottom levels of employees and develop a team work.
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7.1 How to Practice 5S
7.1.1 Seiri
Identify the things which are not of use anymore. Examples are defective
equipments, outdated material and obsolete documents etc. The following guide can
be used to classify all the necessary items.
Guide to Classify Unnecessary Items
The company should have a set of objective criteria on the retention and disposal of
items.
Unnecessary Items
Items of some Value
Items of no Value
Items required special disposal
Sorting
Throw away Immediately
Relocate or Sell
Look for an in-expensive safe way for disposal
Action Require
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7.1.2 Seiton
It is important to prepare a plan for the location of the objects. The plan will make it
easier to locate items when they are needed. It is important to return the items to
their original place after use. The following guide can be used to help in arranging
the necessary items.
Guide to classify Necessary Items
It is likely to forget the location of certain objects not often used. To prevent this,
“Visual Control” can be used to mark out the items and their locations. With
properly marked storage places, out of place items can be easily spotted. The use of
colors, labels, charts can be used for visual control.
Necessary Items Items used
Occasionally
Items used Constantly
Items not used frequently but still in-need
Sorting
Must be placed nearby
Can be placed further away
Must be stored separately in a designated place
Action Require
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7.1.3 Seiso
The practice of Seiso is important for the company’s image and health of its
employees. It is also prerequisite for the production of quality goods and services.
Following are the some ways to implement Seiso at the workplace:
Organize a big cleaning day once or twice a year that involves everyone
Set aside some time each day to clean workplace. Cleaning work is easier
and faster when done daily as the dirt accumulated would be minimal
Employees to be made responsible for the cleanliness of their own
immediate work areas
Conduct regular cleaning of machines and tools that are in use. This would
be a good starting point for productive maintenance because clean
machinery and equipment encounter fewer breakdowns
7.1.4 Seiketsu
To maintain a high standard of workplace by keeping everything clean and orderly
at all times the 5S movement must be sustained within the company by repeating
Seiri, Seiton and Seiso activities. The 5S must be implemented according to a
company wide standard. The purpose is to make sure that the entire organization
follows the same rules; same names and colors etc.
Following are some guidelines for Seiketsu (Standardization):
Create a cleaning system for house keeping. For example, make a weekly
schedule for cleaning and organizing the workplace
Form 5S teams among the various departments to brainstorm on possible
housekeeping projects. These will help in creating a sense of ownership and
participation among the employees. The achievements by these teams
should be exhibits to both management and colleagues to share their
experiences
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Organize inter-departmental competitions on housekeeping. These will
bring motivation and create the importance of housekeeping at the
workplace. Also it will help to create new ideas on visual control to be
implemented resulting higher productivity
7.1.5 Shitsuke
The 5S program is a long term approach to improve the work environment. The
benefits could only be fully realized through the continued efforts of every
employee in the organization. Total participation is must for Shitsuke to succeed.
The organization should train all the employees and develop a company culture
whereby good housekeeping becomes a habit for everyone.
Following are some ways to implement it:
Every one should play an effective role in housekeeping efforts at the
workplace to set good examples for others to follow
Plan a comprehensive training on 5S and implement it
With continuous improvement in mind the changes brought at workplace to
convince employees and create positive attitude towards 5S
Create a 5S culture where everyone willingly participates and give rewards
on good practices
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8 Fish Bone Theory
The Fish Bone Theory is a simple and systematic Japanese approach for solving the
problems. It should be gradually adopted than it will become the organizational
habit. After analysis of the data, this theory must be used for solving different types
of problems. Fish Bone Diagrams help you to think through causes of a problem
thoroughly. Its major benefit is that it push you to consider all possible causes of the
problem, rather than just the ones that are most obvious. The approach combines
brainstorming with use of a type of Concept Map.
Follow these steps to solve a problem with a Fish Bone Diagram:
8.1 Identify the Problem
Write down the exact problem you face in detail. Where appropriate identify who is
involved, what the problem is, and when and where it occurs. Write the problem in
a box on the left hand side of a large sheet of paper. Draw a line across the paper
horizontally from the box. This gives you space to develop ideas.
8.2 Work out the major factors involved
Next identify the factors that may contribute to the problem. Draw lines off the
spine for each factor, and label it. These may be the people involved with the
problem, systems, equipment, materials, external forces, etc. Try to draw out as
many factors as possible. If you are trying to solve the problem as part of a group,
then this may be a good time for some brainstorming. Using the 'Fish bone'
analogy, the factors you find can be though of as the bones of the fish.
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8.3 Identify Possible Causes
For each of the factors you considered in stage II, brainstorm possible causes of the
problem that may be related to the factor. Show these as smaller lines coming off
the 'bones' of the fish. Where a cause is large or complex, then it may be best to
break it down into sub-causes. Show these as lines coming off each cause line.
8.4 Analysis your diagram
By this stage you should have a diagram showing all the possible causes of your
problem. Depending on the complexity and importance of the problem, you can
now investigate the most likely causes further. This may involve setting up
investigations, carrying out surveys, etc. These will be designed to test whether
your assessments are correct.
The examples of fish bone diagram as applied in knitting are attached in the
annexure-IX.
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9 Employee Participation & Training
Organizations should make full use of its employees- its most valuable resource.
Employees actually performing the operations often have the best idea for
improving them. Human resource is as essential an aspect of processes as
technology. The abilities of managers and workers, and how they are organized,
trained and motivated can give a firm a competitive edge. Firms can capitalize on
the insights and experience of their employees in various ways, ranging from
departmental problem-solving teams to cross-functional, self-directed teams.
However, to utilize fully the talents of their work force, firms must establish the
proper environment, which includes restructuring the organization and its
incentives, appropriately designing jobs, and using the proper tools to measure
performance.
9.1 Employee Training
Organization must rely on their employees to anticipate possible problems, develop
new product, increase productivity and quality to remain competitive. In order to
make it possible On-job training is one of the useful tools. Teaching new work
methods to experienced workers or training new employees in current practices
helps to achieve our goal.
Managers too need to develop new skills not only those directly relating to their
own duties but also those needed to teach their sub ordinates.
Systematic training involves the training of a person in: -
Basic knowledge
Correct methods
Quality standards (It means the establishment of the threshold at which level
of severity a defect becomes unacceptable, i.e. a fault.)
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Without this last item defective production cannot be prevented. It is vital that all
faults and defects that are likely to arise in any job should be taught to all trainees
during their instruction. An operative must be able to recognize these faults and
take action on them, that is, to report, correct or prevent them and where possible,
to prevent their recurrence.
Training of Quality standards is greatly assisted by a library of faults, each fault
being illustrated in the various degrees of severity, - from certainly acceptable to
definitely no.
Good quality products can only be produced by the operatives, or those who fold
and pack no one else. They cannot produce quality without being fully aware of
what exactly is required. Responsibility for the production of good quality lies with,
and is in the hands of, the person teaching the job, primarily by good
communication, by making the newcomer aware of specifications and tolerances,
faults themselves, their effect and the appropriate action to take.
Such communication or training if properly planned and executed will greatly assist
in minimizing the cost of poor quality. The operatives will know from the start what
is required, and equally important be able to spot trouble before it gets out of hand
and know how to handle it. It will also help to avoid the painful scenes of huge piles
of sub-standard work being returned for rectification, which more often than not are
due to a lamentable lack of positive communication. Only in this way will quality
be controlled, costs remain at an acceptable level and customers be satisfied.
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
ANNEXURE
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
Annex-I: Knitting Program Chart
Machine #
Machine Type
Machine Gauge / Dia
Machine RPM
Work Order #
Yarn Count
Yarn Brand
Fabric Type
Slitting Line YES NO
Stitch Length
GSM
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
Annex-II: Data Chart for Knitting Conditions
1 2 3 4Yarn Count
1 2 3 4Stitch Length
Round Meter
Yarn Tension
Sinker Timing /Needle Timing
Feeders Position
Master Wheel Gear Teeth Master Wheel MPF Tape No.
Greige GSM Finish GSM
Possible Problems that Occurred
Possible Solution must be kept Future
Reference
Date Work Order No.
Machine No. Pattern
Dia Gauge
No. of Feeders RPM
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
Annex-III: Machine Counter Status
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
Annex-IV: Production Analysis Graph
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
Annex-V: Machine Wise Inspection Report
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
Annex-VI: Machine Maintenance SchedulePeriodical Maintenance Sheet
If any abnormality should be found during operation, please stop the machine immediately and take necessary corrective measures.
Frequency or timing
Items to be inspected
Before Installation
Enough room space for machine installation Electric wiring by qualified electricians Air piping work by qualified techniciansYarn feeding device and related parts: Yarn feeders (MPF, IRO, YS2, etc.):Slipped-off, loose or broken drive belt Positive yarn feeders (MPF**, MFD**, etc.): Malfunction of clutch, IRO tape flipper, etc. Lint accumulation onto yarn feeders including tension cymbals QAP (Quality pulley):diameter, loose lock nut
Lubricators: Oil level in the tank Supply amount of compressed air Lubricating condition for knitting elements (disconnections, leakage, etc.) Compressed air pressure Supply amount of lubrication oil
Abnormal noise: Knitting elements (cam holders, sinker cap and dial cap) Yarn feeding units and related parts (QAP, change gear box, drive tape, etc.) Frame (machine bed, take-up unit, motor drive, etc.)
Daily
Oil leakage: Lubricator main body Part underneath the bed Oil amount in the oil sump bottle Connection between oil mist pipes and nozzles Part underneath the gear ring
Weekly
Piping for lubrication oil and compressed air Oil amount in the bed Oil sump channel(for oil mist sump) Draining of water in the air compressor
Lint accumulation (checks for lint and clean.): Lint in the control panel Lint around lint fans and other areas Lint in the motor coverMonthly
Belt tension: Drive motor belt Drive belts for yarn feeding device
Semi-annual Oil change for the gear box and the bed
Annual Grease change for the take-up unit and the yarn feeding units
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
Daily Machine Inspection Check Sheet
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
Weekly Machine Inspection Check Sheet Piping for lubrication oil &
compressed airOil amount in the bed Oil sump channel for oil
mist sumpDraining of water in the air
compressorMONTH
Week1
Week 2
Week 3
Week4
Week1
Week2
Week3
Week4
Week1
Week2
Week3
Week4
Week1
Week2
Week3
week4
JAN
FEB
MAR
APR
MAY
JUN
JULAUG
SEP
OCT
NOV
DEC
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
Monthly Machine Inspection Check SheetLint accumulation
(check for Lint &Clean)Belt TensionM
ONTH
Lint in the control panel
Lint around lint fans & other areas
Lint in the motor cover
Drive motor belt Drive belts for yarn feeding device
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
Inspection Check Sheet
Semi-Annual Annual
GREASE CHANGEYEAR TAKE-UP
UNITYARN FEEDING
UNITS
OIL CHANGEMONTH GEAR
BOXBED
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
Annex-VII: Lubrication
NOTE1. Please use the oil described in above the table or same quality, pure and clean oil.
When adding oil, please ensure dust lint etc. does not get in to the machine.
2. If the machine becomes too hot or if there is an unusual noise, stop the machine immediately and check the lubricating conditions.
3. The bed, gear box and stationary bevel gear are each design with an oil bath system.Please exchange oil periodically, as recommended in the table. If any of the oil amount falls to the minimum level. Please immediately add oil.The bed oil gauge will not shown accurate amount of oil during the operation of the machine(There are cases when showing as “0”), so when confirming the amount, stop the machine, and after about 5 minutes, please confirm the oil amount.
Lubrication LocationLubrication Procedures & Number of Time
Oil Used
Bed (Gearing)
Gear Box
After test running of 1 month,Thereafter every 6 months
SHELL: TONNA OIL S68(Please use the oil described in
above or same quality ofViscosity@40˚C 55 to 70)
Take-Up Device(Ratcht Wheel,Super Gear, Stationary Bebel Gear & Bearing)
Manually---- once a yearSHELL : ALVANIA GREASE # 2MOBIL : MOBILUX GREASE #2
Needles, Sinkers & Cams
Continuously by automaticoil mist lubrication
SHELL: VEXILLA GMOBIL: VILOCITE CX 22VICKERS: SPOTLESS C. N. 22 : VICKERLUBE L. C. 22(Specially develop for use with Lycra when heat setting is the first finishing operation.) MILLERS: KAYSTOLGULF : LORTEX 22ESSO : TELURA KLUSER : Text- 22N
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Annex- VIII: Knitting Construction Graph
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
Knitting Construction Graph
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
Knitting Construction GraphSample No. Single Knit
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
Annex-IX: Fish Bone ChartFor Productivity Improvement
ConeLoop Length
Speed Fluff
Gauge Shape of ConeKind of Pattern
Crush Dent or HollowCount
Yarn Speed No. of Feeder
Stopper
Centering of Creel Scratch
Tension Mind M PF Tape
Positioning of Tail Knot Education Yarn Carrier O peration
NeedleNeedleBed
Needle Ditch Regular Check
Improvement ofProductivity
Paper Tube
Yarn
ProductionControl
KnittingC ondition
O perator
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
For Oil Stain Winding
Periodic Upkeep Guide
StorageStandard Action
Needle
Place of LubricationNeedle Bed
TransportLubrication Needle Ditch
Oil Pack Oil Volume
Oil Volume Storage
Place ofCheck Lubrication Knot
Reception
Dyeing Transport Tail Periodic Upkeep
ConeGuide
Production Control
Stain
Yarn
Dyeing Factory
Inspection
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
For Vertical Line
Friction Declination of Pattern Bend
Difference of Design
High Wearing
Friction FrictionMotionless
Measure Frame Latch
Friction
Rivet BendDamage
Friction Loose Fitting Hook
Roller Friction
Butt
Difference of Pattern Needle ditch & Bed
Vertical Line
Needle
Touch Line
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
For Dropped Stitch
LatchNeedle
Kind of PatternLoop Length Yarn Speed Gating
Yarn Speed BendTension Levering
Timing Position Creel
Guide
Winding Tension Scratch Space of Guide
Hardness Slipping from Cone Cone
Dent or Hollow Hairiness Tight Snarl
QualityTail
Tail Knot
Knitting Condition
Production Control
Dropped Stitch
YarnPaper Tube
SMEDA-JICA Industry Support Program Best Practices Knitting Manual
For Needle Break
Loop Length
Kind of Pattern
Cone Yarn Speed
Adjustment
Needle Ditch Cam
Friction Gating Needle Needle
Bed
Needle Latch Regular check
Operation Pressure Weight
Winding Tension
Yarn
Needle Break
Production Control
Knitting Condition