Presentation on process control study in spinning dpt.
3. LIST OF MAJOR DEPARTMENT IN
SPINNING
BLOW ROOM
CARDING
RIBBON LAP
SLIVER LAP
COMBER
DRAW FRAME
SPEED FRAME
RING FRAME
AUTOCONER
TFO
4. OBJECTIVE OF BLOW ROOM
It is the sequence of machines for opening & cleaning of fibres. For
opening and cleaning there are beater in the m/c Beating elements :
There are three types of beaters
1. Pin beaters
2. Bladed beaters
3. Saw tooth beater/opener
Recent beater:
a) Axiflow cleaner
b) Mono-cylinder
c) ERM cleaner
d) Cleaner R.K.
Cleaning Operation :
1 Breaking of fibre flocks in B/R.(Flocks - Bunch of
fibre .)Opening of fibre to single fibre state is achieved at card &
OE spg. m/c .
5. The basic purpose of Blow room is to supply
•small fibre tufts
•clean fibre tufts
•homogeneously blended tufts if more than one variety of fibre is
used to carding machine without increasing fibre rupture, fibre
neps , broken seed particles and without removing more good
fibres.
The above is achieved by the following processes in the blow
room
1.Pre opening
2.pre cleaning
3.mixing or blending
4.fine opening
5.dedusting
CLEANING EFFICIENCY:
Cleaning efficiency of the machine is the ratio of the trash removed by
the machine to that of total trash feed to the machine, expressed as
percentage
Cleaning efficieny % =(( trash in feed % - trash in del %) x 100) / (trash in
feed%)
6. Following are the basic parameters to be considered in
Blow room process.
•No of opening machines
•Type of beater
•Type of beating
•Beater speed
•Setting between feed roller and beater
•Production rate of individual machine
•Production rate of the entire line
•Thickness of the feed web
•Density of the feed web
•Fibre micronaire
•Size of the flocks in the feed
•Type of clothing of the beater
•Point density of clothing
•Type of grid and grid settings
•Air flow through the grid
•Position of the machine in the sequence
•Amount of trash in the material
•Type of trash in the material
•Temp and relative humidity in the blow room department
7. PREOPENING:
Effective preopening results in smaller tuft sizes, thus creating a large surface
area for easy and efficient removal of trash particles by the fine openers. Like:-
Unifloc (Rieter) or Blendomat (Trutzschler)
U
PRECLEANING:
Precleaning should be gentle. Since removing finer trash particles is difficult ,
seeds and bigger trash particles should not be broken. Finer trash particles
require severe treatment in Fine openers. This will lead to fibre damage and more
nep generation. Therefore, precleaning should be as gentle as possible and no
compromise on this. If preopening and precleaning are done properly,
consistency in trash removal by fine openers is assured. Dust removal should be
started in this machine. Enough care should be taken remove dust in this process.
Like:-Uniclean,Axiflow,Maxiflow
BLENDING:
Barre or streakiness is due to uneven mixing of different cottons. Hence
mixing technology is a decisive factor in spinning mill technology
•bigger the differences of cotton parameters like fineness, color and staple length,
the greater the importance of mixing .Like:-MPM
8. •FINE CLEANING:
•Fine cleaning is done with different types of machines. Some fine cleaners are with single
opening rollers and some are with multiple opening rollers.
•If single roller cleaning machines are used, depending upon the amount and type of trash
in the cotton, the number of fine cleaning points can be either one or two.
•DEDUSTING:
•Apart from opening cleaning of raw material, dedusting is the very important
process in blow room process.
•normally dedusting starts with precleaning
•dedusting keeps the atmospheric air clean
• dedusting in machines like unimix , ERM
9. No of neps and trash particles after different processes is given below.(an approximate
value)
•Blow room machinery lay out should
10. SOME IMPORTANT FECTOR IN BLOW ROOM
setting between feed rollers is different for different types. It should b
according to the standard specified by the manufacturer.
it is advisable to run the fans at optimum speeds. Higher fan speeds wil
increase the material velocity and will create turbulence in the bends.Thi
will result in curly fibres which will lead to entanglements.
If the feeding to cards is not with CONTI -FEED, the efficiency of the
feeding machine should be minimum 90 % and can not be more than 95%.
fan speeds, layout of machines should be selected in such a way that
material choking in the pipe line, beater jamming etc will not happen. This
will lead to quality problems
all blowroom machines should work with maximum efficiency. The feed
roller speeds should be selected in such a way that it works atleast 90% of
the running time of the next machine.
11. •Blow room stoppages will always affect the sliver quality both in terms of
linear density and tuft size. Blow room stoppages should be nil .
heavy particles like metal particles, stones should be removed using
heavy particle removers , double magnets etc, before they damage the
opening rollers and other machine parts.
Number of cleaning points are decided based on type of ginning (whether
roller ginned or sawginned), the amount of trash, and the number of trash
particles and the type of trash particles.
Since blow room requires more space and power, it is better to make use
of the maximum production capacity of the machines
material level in the storage chambers should be full and it should never
be less than 1/4 th level.
grid bars should be inspected periodically, damaged grid bars should be
replaced.
grid bars in the front rows can be replaced earlier
if the cotton is too sticky, the deposits on the machine parts should be
cleaned atleast once in a week, before it obstruct the movement of the fibre
12. fibre rupture should be checked for each opening point. 2.5 % span length should
not drop by more than 3% . If the uniformity ratio drops by more than 3%, then
it is considered that there is fibre rupture.
high fan speed, which will result in high velocity of air will increase neps in cotton
nep is increased in the blowroom process. The increase should not be more than
100%.
the nep increase in each opening machine should be checked with different
beater speeds and settings, and the optimum parameters should be selected. But
please remember that everything should be based on yarn quality checking. e.g.
if nep increase in blow room is more and the beater speed or feed roller setting is
changed, the tuft size will become more. This may result in bad carding quality.
Sometimes if the neps are slightly more and the fibre is well opened, the neps can
be removed by cards and combers and the yarn quality may be better. Therefore
all trials should be done upto yarn stage.
•fibre travelling surface should be smooth and clean
temperature should be around 30 degrees and the humidity is around 55 to 60%.
13. LIST OF MAJOR STUDIES
•BLOW ROOM
•Blow room lap CV
Blow room lap rejection
Blow room waste
Blow room cleaning efficiency
Blow room beater speed
Lint trash ration
14. OBJECTIVE OF CARDING
1.To open the flocks into individual fibres
1. 2. cleaning or elimination of impurities
2. 3. reduction of neps
3. 4. elimination of dust
4. 5. elimination of short fibres
5. 6. fibre blending
6. 7. fibre orientation or alignment
7. 8. sliver formation
TECHNOLOGICAL POINTS IN CARDING
• There are two types of feeding to the cards
1. 1.feeding material in the form of scutcher lap
2. 2.flock feed system (flocks are transported pneumatically)
• lapfeeding
.
15. lap feeding :
1. linear density of the lap is very good and it is easier tomaintain
(uniformity)
2. the whole installation is very flexible deviations in card output will be nil,
as laps can be rejected
3. autolevellers are not required, hence investment cost and maintenace cost
is less
4. 0transportation of lap needs more manual efforts( more labour)
5. 0lap run out is an additional source of fault, as it should be replaced by a
new lap
6. 0more good fibre loss during lap change
7. flock feeding :
8. 0high performance in carding due to high degree of openness of feed web
9. labour requirement is less due to no lap transportaion and lap change in
cards
10. flock feeding is the only solution for high prouduction cards
11. linear density of the web fed to the card is not as good as lap
12. installation is not felxible
13. autoleveller is a must, hence investment cost and maintenance cost is more
4)
16. Feeding zone - Feed table , Feed roller , Licker- in
Carding zone - Cylinder , flats
Total draft at card is 80 - 120 .
Between licker-in & cylinder Draft is 5 - 6.
Objectives of Licker-in:
(1) Unwinding of lap at continuous rate
(2) Preliminary opening of material .
(3) Cleaning of impurities.
(4) Transfer of material .
Factor responsible for transfer of material from licker-in to
cylinder:
(1)Point to back arrangement of rollers . Cylinder has forward
pointing arrangement .
(2) Closer setting - 7 thous
(3) Higher speed of cylinder
(4) Generation of air current as surface move at very high speed
This help in transfer of material.
17. . Licker-in does not deliver 100% individual fibres to main cylinder. It
delivers around 70% as small flocks to main cylinder. If carding segments are not
used, the load on cylinder and flats will be very high and carding action also
suffers. If carding segemets are used, they ensure further opening, thinning out
and primarily, spreading out and improved distribution of the flocks over the
total surface area.carding segments bring the following advantages
1.improved dirt and dust elimination
2.improved disentanglement of neps
3.possibility of speed increase (production increase)
4.preservation of the clothing
5.possibility of using finer clothings on the flats and cylinder
6.better yarn quality
7.less damage to the clothing
8.cleaner clothing
"CYLINDER-FLATS" area is by far the most effective region of the card
for.
1.opening of flocks to individual fibres
2.elimination of remaining impurities(trash particles)
3.elimination of short fibres( neps also removed with short fibres)
4.untangling the neps
5.dust removal
18. •The intensity of nep separation depends on
1.the sharpness of the clothing
2.the space setting between the main cylinder and the flats
3.tooth density of the clothing
4.speed of the main cylinder
5.speed of the flat tops
6.direction of flats with reference to cylinder
7.the profile of the cylinder wire
8.It was indicates that 75% of all neps can be disentagled, and of these
about 60% are in fact disentagled. Of the remaining 40% disentaglable
neps
9.30-33% pass on with the sliver
10.5-6% are removed with the flat strips
11.2-4%are eliminated with the waste
19. Effect of increased speed of licker-in:
Higher licker in speed means increased action
exerted by licker-in on fibre. There will be a better chance to minimize
the tuft size . So cylinder will receive more opened material and hence the
carding action will be better but this increases air flow within the card
and result in good amount of fibre loss in the form of licker-in waste
material with stand- ared setting & normal card construction . The
amount of licker-in waste increases rapidly with increased licker-in speed,
of course improves impurities extraction & also in attaining a greater yarn
strength .
Effect of increase in Cylinder speed:
With increase in cylinder speed the transfer index from cylinder to
doffer is increased & therefore cylinder load is decreased .Higher cylinder
speed results in doffer strips and cylinder fly . Any increase in cylinder
speed do not produce any change in fibre length or %age of short fibre.
Increase in cylinder speed for a constant doffer speed increases the no. of
trailing hooks and reduces no.of leading hooks.
20. Effect of increase in doffer speed :
With increase in doffer speed the production of card
can be increased in the same proportion
the same proportion without increase in sliver linear
density. Therefore feed & deliver more quickly in the
doffer,but opg.& clg. organs, such as licker-
in,cylinder,flats run at same speed resulting in less opg. &
clg. of cotton. Loading of cylinder will also increase due to
increase in feed .This will result in lesser carding action
between cylinder & flats .Hence carding quality will
deteriorate.
21. CARDING:
(1). P =( L x 1.0936 x 60 x effy ) / (hank (Ne) x 36 x 840 x 2.2045)
P - production in kgs / hr
L - delivery speed in m/min
effy- efficiency
Ne - English count ( number of 840 yards in one pound)
840 - constant
2.2045- to convert from lbs to kilograms
(2).production in kgs / hr = (L x Ktex x 60 x effy) / ( 1000)
L - delivery speed in m/min
Ktex- sliver count in Ktex (kilotex)
effy - efficiency
1000- to convert to kilograms from grams
(3). production in kgs / 8 hrs = (0.2836 x L x effy) / (Ne)
L - delivery speed in m/min
effy - efficiency
Ne - English count
(4).prodn / 8 hrs = (Hank x Nd) /( Ne x 2.2045)
Hank = no of hank (840 yards)delivered by the machine
Nd = no of deliveries
Ne = hank of the material
(5).Total draft in card = (feed weight in g/m) / (sliver weight in g/m)
23. OBJECTIVE OF DRAW FRAME
1. Through doubling the slivers are made even
1. 2.doubling results in homogenization(blending)
2. 3. through draft fibres get parallelised
3. 4.hooks created in the card are straightened
4. 5. through the suction ,intensive dust removal is
achieved
5. 6.autoleveller maintains absolute sliver fineness
• 7. Quality of the drawframe sliver determines the yarn
quality.
• 8.Drawing is the final process of quality improvement in
the spinning mill
24. •Drafting arrangement is the heart of the drawframe. The drafting
arrangement should be
1.simple
2.stable design with smooth running of rollers
3.able to run at higher speeds and produce high quality product
4.flexible i.e suitable to process different materials , fibre lenths and
sliver hanks
5.able to have good fibre control
6.easy to adjust
•Roller drafting causes irregularities in the drafted strand since there is
incomplete control of the motion of each individual fibre or fibre
group.The uniformity of the drafted strand is determined by
draft ratio
1.roller settings
2.material characteristics
3.pressure exerted by the top roller
4.hardness of top roller
5.fluting of the bottom rollers
6.distribution of draft between the various drafting stages
25. •drafting is affected by the following rawmaterial factors
1.no of fibres in the cross section
2.fibre fineness
3.degree of parellelisation of the fibres
4.compactness of the fibre strand
5.fibre cohesion which depends on
1.surface structure
2.crimp
3.lubrication
4.compression of the strand
5.fibre length
6.twist in the fibre
7.distribution of fibre length
26. DRAWFRAME:
(1.)Break draft = surface speed of 2nd roller / surface speed of back
roller
(2).Main draft = surface speed of 1st roller / surface speed of
2nd( middle) roller
(3).Total draft = surface speed of delivery roller / surface of feed roller
(4).production in kgs / 8 hrs = (0.2836 x L x effy x Nd) / (Ne)
L - delivery speed in m/min
effy - efficiency
Ne - english count
Nd - No of delvieries
(5.).prodn in kgs / hr = (FRD x FRrpm x 3.14 x 60 x effy x Nd) / (Ne x
840 x 36 x 2.2045)
FRD - front roller dia in inches
FRrpm - front roller rpm
effy - efficiency
Ne - Sliver hank
Nd - number of deliveries
27. Drafting wave: Nip to nip distance is called Reach . If Reach
is more than length of fibre. Thick & thin places appear and is
known as Drafting wave.Drafting wave can be minimised by
Doubling or autoleveller
Roller slip : When the motion of bottom roller is not
completely trans-fered to top roller then the top roller speed is not
same as bottom roller speed.This can be eliminated by modify-ing
drafting arrangement Due to eccentricity in any of the rollers,nip
may or may not be in contact always.This adds to irregularity in
material . Roller slip can be minimised by using auto leveller.
Pressure applied can be of following types :
1 Pneumatic (modren m/cs)
2 Spring loading
3 Dead weight
4 Hydrolic
5 Magnetic
28. Factors which affect roller slip waves are:
1 Thickness of fibre in nip
2 Nip to nip distance
3 Amount of draft
4 Drafting speed
5 Condition of the drafting rollers
6 Amount of weighting of top roller
7 Degree of orientation of fibre
Ideal drafting conditions are : Ideal conditions means
there is no irregularities.
1 Fibre length that should be equal for all the fibres.
2 movement of drafting rollers should be steady
3 Degree of parallelization i.e. fibres are arranged in per- fect
parallel fashion in ideal drafting. There will be no additional
irregularity .
4 Roller slip should not be there. When one fibre ends second
fibre should immediately start.
29. Drafting system :
Varies form manufacturer to manufaturer .
Doubling
Hank or count will be changed by factor = ---------
draft
Performance Assessment of Drawframe:
1 Unevenness %age of the sliver is measured by means of uster
tester.We get idea of short term variation sliver. sliver passed between
two capacitors.As thickness varies capacitance which varies current
flowing Therefore variation can be found.
we can find CV %, CV % has no units so we can compare CV %
of two diff. products .
S.D. x 100
CV % = --------------------
Mean
CV % = U % * 1.25
1.
30. 1. Wrapping CV % ( wrapping of 5m) Give idea of medium term
irregularity is determined by computing the CV of mt.wrapping for
this a 5mt. piece of finisher drawing sliver is cut and weighed. A
total of about 30 readings should be taken covering all the deliveries
processing a particular mixing . Then calculate CV.If the CV dose
not exceed 2%,the performance of m/c will be considered
satisfactory .
Average Hank : Collect the sliver from all the finish-er deliveries at
least once shift.Determine the wt.of 5mt. pieces .A total of 6 such
readings per frame should be taken . If the avg. hank differ from
the nominal hank by 1.67 % then the performance of m/c.will be
considered as unsatisfactory. Nominal hank is according to
standards.
31. 4. Sliver breakage rate :No. of breakage in certain time
.Standard is set & value is compared to determine perfor-
mance of m/c.
Surface speed of front
roller
Mechanical draft = ----------------------
Surface speed of back
roller
Hank delivered
Actual draft = ----------------
Hank feed
So actual draft > Mechanical draft
32. MAJOR STUDIES AT DRAW FRAME
Draw Frame Uster
Hank CV
Sliver Test(RSB)
Stop Motion
D/F Speed
Nip load Pressure DO2S
D/F Breakage
Top roll checking
33. OBJECTIVE OF COMBER
Combing is the process which is used to upgrade the raw
material. It influences the following yarn quality
1.yarn evenness
2.strength
3.cleanness
4.smoothness
5.visual appearance
In addition to the above, combed cotton needs less twist than a carded yarn.
TASK OF THE COMBER:
To proudce an improvement in yarn quality, the comber must perform the
following operation.
1.1.0elimination of short fibres
2.2.elimination of remaining impurities
3.3.elimination of neps
•4.The basic operation of the comber is to improve the mean length or staple
length by removing the short fibres.
34. Material preparation factor :
In sliver lap former, draft is tension draft . It is in range of 1.5 - 3.0
. Doubling is most in this m/c.Longitudinal doubling takes place.In
ribbon lap former, transverse doubling takes place.
Factors:
1. Parallelisation of feed fibres in sheet.
2. Sheet thickness.
3. Sheet evenness
4. orientation of fibre hooks.
If hooks are present, they are easily caught by the comb &
removed .If trailing hooks are prevalent waste %age is more. Coefficient
of friction is higher, so less is the efficiency . Distance between nipper and
comber is decided by avg. fibre length Uniformity effects efficiency of
combing . Combing quality is affected by M.C Extra parallelisation
also effects combing quality. Waste %age in comber is 5 - 20 %. If we
need fine quality then we go for this process but noil % should be 10-15%
Removal of this waste gives more evenness to yarn.
35. Machine factors:
1. Condition of machine
2. Condition of comb
3. Speed of m/c.
4. Setting
5. Drafting arrangement
Machine settings:
A. Feed distance
B. Detachment setting
C. Point density
D. Depth of penetration of top comb
36. RIBBN LAP,SLIVER LAP,LAP FORMER&COMBER
Lap CV for R/L,S/L & Lap Former
Neps checking of R/L,S/L,L/F & Comber
Noil Checking of comber
Stop motion checking of comber
Comber speed
Top Comb Cleaning checking
Hank CV
Comber Uster
37. OBJECTIVE OF SPEED FRAME
It is a sensitive zone in spg. Roving machine is complicated,
liable to faults, causes defects, adds to production costs and delivers
a product that is sensitive in both winding and unwinding.
Why we use roving frame:
1. Drafting of material is required
2. to facilitate transportation of material from D/F to R/F .
Objects:
1. To draft the material . Material from this is rove which are very
fine . In order to hold them we have to introduce some factor which is
a)twist
b)winding.
Draft is in range of 5 – 20
Twist imparts strength to the material.Main parts of twist are flyer
and spindle
38.
Flyer rpm
Twist / metre = ---------------------------
Delivery rate m/min.
By changing delivery speed we can change amount of twist.
Flyer rpm is in the range of 1500. but normally we apply 1200rpm. In order
to impart draft, twist has to be neutralized. By increasing twist, we reduce
productivity.We apply break draft & is employed at back zone of drafting
system. Amount of break draft is in range of 1.1 . Break draft prepares the
material for drafting action. Its range is 1.05 - 1.15 . Pressure is responsible for
imposing winding tension & tension is responsible for building package. Tension is
changed by changing no.of turns along the flyer length . Flyer top has some
grooves Normally 8 grooves are there.If flyer cap is not placed, then twist is
given , some part will flow in the backward zone .Grooves are known as false
twist attachment.It maintains continuity to the in coming sliver If lacks then
reduces strength & regularity of yarn. It is called false twist because twist
imparted is eliminated in the yarn.
Pressure on top roller: Normally pneumatic pressure is used . It ensure
proper gripping of the fibre in drafting zone . The uncontrolled movement is only
responsible for irregularity.
39. MAJOR STUDIES AT SPEED FRAME
Speed frame Uster
Speed frame breakage
Speed frame speed
Top arm pressure
Stop motion
Hank CV
Stretch % of roving
40. OBJECTIVE OF RING FRAME
1. Drafting :-to draft the roving until the required fineness is
achieved
2. Twisting:-to impart strength to the fibre, by inserting twist
3. Winding :- to wind up the twisted strand (yarn) in a form
suitable for storage, transportation and further processing .Total
Draft - In range of 15 - 20
In ring frame we prefer apron drafting system . Apron is made
of rubber or leather. They give support to the floating,fibre& it
has better evenness. Particular distance is maintained between two
aprons (top & bottom )by spacer.Spacing size is affected by
A. Denier B. Length
C. Crimp D. Fibre friction coefficient
E. Hank of rove F. Draft.
Break draft is in the range of 1.3 .
41. No. of factors decide break draft:
1. Roller setting and drafting system.
2. Type of fibre means frictional coefficient .If fibre friction
coefficient is higher then break draft is required.
3.Total draft employed in m/c.
Top rollers are mounted with synthetic coat.hardness of coat
should be more than in D/F because material passed is more
compact than in D/F . Frequency of coat change is higher in R/f
than D/F.Without break draft rove cannot be converted to
yarn.Rove is very compact so high break draft is required .
Performance Assessment of Ring frame:
1. Yarn quality
2. End breakage rate /productivity
42. •RUBBER COTS AND APRON:
For processing combed cotton, soft cots (60 to 65 degree shore hardness)
will result in lower U%,thin and thick places.
•There are different types of cores (inner fixing part of a rubber cot)
available from different manufacturers.Aluminimum core,PVC core,etc. It
is always better to use softer cots with aluminium core.
•When softer cots are used, buffing frequency should be reduced to 45 to
90 days depending upon the quality of the rubber cots, if the mill is aiming
at very high consistent quality in cotton counts.
If the lapping tendency is very high when processing synthetic fibres for
non critical end uses, It is better to use 90 degree shore harness cots, to
avoid cots damages. This will improve the working and the yarn quality
compared to working with 83 degree shore hardness.
•If rubber cots damages are more due to lapping, frequent buffings as high
as once in 30 days will be of great help to improve the working and quality.
Of course,one should try to work the ringframe without
lapping.
43. •The basic reasons for lapping in the case of processing synthetic
fibre is
•End breaks
•Pneumafil suction
•rubber cots type
•fibre fineness
•Oil content(electrostatic charges)
•department temprature and humidity
•Almost all the lappings orginate after an end break. If abnormally
high lapping problem
the first thing to do is to control the end breaks,
1.after doffing
2.during speed change
3.during the maximum speed
44. •TWIST:
The strength of a thread twisted from staple fibres increases with increasing twist,
upto certain level.Once it reaches the maximum strength, further increase in twist
results in reduction in yarn strength
•Coarser and shorter fibres require more Twist per unit length than finer and
longer fibres.
•Twist multiplier is a unit which helps to decide the twist per unit length for
different counts from the same raw material.
•TWIST PER INCH = TWIST MULTIPLIER * SQRT(Ne)
•cotton combed knitting T.M. = 3.4 to 3.6
•cotton combed weaving T.M. = 3.7 to 3.8
•cotton carded knitting T.M. = 3.8 to 4.0
•cotton carded weaving T.M. = 3.9 to 4.2
•The above details are for cottons of 2.5% span length of 27 to 30 mm and the
average Micronaire of 3.7 to 4.4. For finer and longer staple, the T.M. will be
lower than tha above.
•In general for processing poly/viscose , the T.M. is as follows
51 mm, 1.4 denier fibre : T.M. = 2.7 to 2.9 for knitting application
•51 mm, 1.4 denier fibre : T.M. = 2.9 to 3.1 for weaving application
•44 mm, 1.2 denier fibre : T.M. = 2.9 to 3.0 for knitting application
•44 mm, 1.4 denier fibre : T.M. = 3.0 to 3.1 for knitting application
•38 mm, 1.2 denier fibre : T.M. = 3.1 to 3.3 for knitting application
45. SPEEDFRAME + RINGFRAME
(1).Twist / Inch (TPI) = Spindle speed / FRS
FRS - front roller surface speed in inches/min
(2).FRS = FRrpm x 3.14 x FRD
FRS - Front roller surface speed
FRD - front roller diameter
(3).T.P.I = T.M. x sqrt(count or hank)
T.M. - Twist multiplier
sqrt - square root
(4).prodn in kgs / 8 hrs = (7.2 x SS x effy) / (TPI x Ne x
1000)
SS - spindle speed
(5).Spindle speed = m/min x TPI x 39.37
(6).hank delivered = spindle speed / ( tpi x 62.89)
(7).Ring traveller speed in m/sec =( spindle speed x ring dia
46. MAJOR STUDIES AT RING FRAME
Count & Count CV
Strength & Strength CV
Uster,IPI & Hairiness
Ring Frame breakage
Twist per inch
Top arm pressure & Suction pressure
Start Up breakage
Snap Study(cots/Apron,cross roving,Idle )
47. OBJECTIVE OF WINDING
Ring spinning produces yarn in a package form called cops. Since
cops from ring frames are not suitable for further processing, the
winding process serves to achieve additional objectives made
necessary by the requirements of the subsequent processing stages.
Following are the tasks of winding process
•Extraction of all disturbing yarn faults such as the short,
long thick ,long thin, spinners doubles, etc
•Manufacture of cones having good drawing - off
properties and with as long a length of yarn as possible
•paraffin waxing of the yarn during the winding process
•introduction into the yarn of a minimum number of knots
•achievement of a high machine efficiency i.e high
produciton level
The winding process therefore has the basic function of
obtaining a larger package from several small ring bobbins.
This conversion process provides one with the possibility of
cutting out unwanted and problematic objectionable faults.
48. WINDING PRODUCTION DEPENDS UPON
•winding speed
•time required by the machine to carry out one splicing operation
•bobbin length per bobbin( both bobbin weight and tpi to be
considered, because TPI will affect the bobbin length). This decides
the number of bobbin changes
•the number of faults in the yarn and the clearer settings, this
decides the clearer cuts
•count
•the number of doffs. It depends upon the doff weight. Higher the
doff weight, lower the number of doffs
•the time taken for each doff either by the doffer or by an operator
•Down time due to red light. It depends upon, number of red lights,
number of repeaters setting for red lights, clearer settings like off
count channel, cluster setting which will result in red lights and
others
•bobbin rejections, it depends on weak yarn, wrong gaiting, double
gaiting, bobbin characteristics etc.
49. WINDING PACKAGE DEFECTS: Following are some of the package
defects which will result in complaints
•Yarn waste in the cones. This is due to loose yarn ends that are wound on
to the cone
•Stitch, drop over, web: Yarn is visible on the small or on the big side of
the cone either across the side , around the tube, or going back in the cone
•Damaged edges or broken ends on the cone: The yarn is broken on the
edges or in the middle of the cone.
•Ring formation: The yarn runs in belt formation on to the package,
because it is misguided
•Without transfer tail: The desired transfer tail is missing or too short
•Ribbon formation: Pattern or ring formation are made by the drum
when rpm are stying the same
•Displaced yarn layers: yarn layers are disturbed and are sliding towards
the small diameter of the cone
•Misguided yarn : The yarn is not equally guided over the hole package
•Cauliflower: On the smaller side of the package, the yarn shows a
wrinkle effect
•Soft and Hard yarn layer: Some layer of yarn are pushed out on the
small side of the cone
•Soft and Hard cones: Great difference in package density from one
50. The yarn faults are classified according to their
length and cross-sectional size,
The cross-sectional deviations are given +% or -% values.
i.e the upper limit, respectively , lower limit with respect
to the mean yarn fault cross-section is measure in %. The
fault length is measured in cms.
Fault Channels:
The various fault channels available in a latest generation
yarn clearer are as follows:
1. Neps
2. Short Thick places
3. Long Thick Places
4. Long Thin Places
5. Count(Dia diff +-)
6. Splice
7.Contamination Clearing(SIRO)
51. Types of Electronic Yarn Clearers
Electronic Yarn Clearers available in the market are principally of two
types –capacitive and optical. Clearers working on the capacitive
principle have ‘ mass’ as the reference for performing its functions while
optical clearers function with ‘ diameter’ as the reference. Both have their
merits and demerits and are equally popular in the textile industry.
Besides the above basic difference in measuring principle, the basis of
functioning of both the types of clearers are similar if not exactly same.
Since most of the other textile measurements like, U% / CV%, thick and
thin places etc., in various departments take into account mass as the
reference parameter, the functioning of the capacitive clearer is explained
in some detail in the following sections.
Functioning Principle
Yarn Clearer Settings
Clearing Limit:
Sensitivity
Reference Length
Yarn Count
Material Number
53. SPLICING:
yarn quality is impossible through knot, as the knot itself is objectionable due
to its physical dimension, appearance and problems during downstream
processes. The knots are responsible for 30 to 60% of stoppages in weaving.
Splicing is the ultimate method to eliminate yarn faults and problems of knots
and piecing. It is universally acceptable and functionally reliable. This is in
spite of the fact that the tensile strength of the yarn with knot is superior to
that of yarn with splice. Splicing is a technique of joining two yarn ends by
intermingling the constituent fibres so that the joint is not significantly
different in appearance and mechanical properties with respect to the parent
yarn. The effectiveness of splicing is primarily dependent on the tensile
strength and physical appearance.
Splicing satisfies the demand for knot free yarn joining: no thickening of the
thread or only slight increase in its normal diameter, no great mass variation,
visibly unobjectionable, no mechanical obstruction, high breaking strength
close to that of the basic yarn under both static and dynamic loading, almost
equal elasticity in the joint and basic yarn. No extraneous material is used and
hence the dye affinity is unchanged at the joint. In addition, splicing enables a
higher degree of yarn clearing to be obtained on the electronic yarn clearer.
56. CHANNEL & SPLICE SETTING OF ALL SUPER, NIKE , COMBED
ORG , LYCRA & SULZER COUN
SETTING CHANNEL SPLICE
N 5.0 5.0
DS 2.0 2.0
LS 1.3 1.3
DL 1.30 1.30
LL 25 20,15
-D -20 -20
L 25 25
OFF COUNT +/- 7.0%
CHANNEL & SPLICE SETTING OF ALL WARP & NT COUNT
SETTING CHANNEL SPLICE
N 7.0 7.0
DS 2.8 2.8
LS 2.8 2.8
DL 1.35 1.30
LL 30 25,20,15
-D -20 -20
L 25 25
OFF COUNT +/- 14.0% (20.0% NT COUNT)
CHANNEL & SPLICE SETTING OF ALL SLUB COUNT
SETTING CHANNEL SPLICE
N 5.0 7.0
DS 3.5 4.0
LS 5.0 4.0
DL 1.70 1.70
LL 70 70
-D OFF OFF
57. CHANNEL & S PLICE S ETTING OF 10 PC , 14 PC & 20 P
S ETTING CHANNEL S PLICE
N 5.0 4.0
DS 2.2 1.8
LS 1.5 1.3
DL 1.30 1.30
LL 25 25,15
-D -20 -20
L 25 25
OFF COUNT +/- 7.9% , 8.0%
CHANNEL & S PLICE S ETTING OF 24 PC NIKE
S ETTING CHANNEL S PLICE
N 5.0 5.0
DS 2.0 2
LS 1.3 1.3
DL 1.30 1.30
LL 25 20,15
-D -20 -20
L 25 25
OFF COUNT +/- 8.0%
CHANNEL & S PLICE S ETTING OF 34 PC & 34 PV
S ETTING CHANNEL S PLICE
N 7.0 7.0
DS 2.8 2.8
LS 2.8 2.8
DL 1.35 1.30
LL 30 30,25,15
-D -20 -20
L 25 25
OFF COUNT +/- 20%
CHANNEL & S PLICE S ETTING OF 15PV , 18PV , 30PC &
40PV , 45PC &
S ETTING CHANNEL S PLICE
N 5.0 5.0
60. WINDING:
(1). production in kgs / 8 hrs = (0.2836 x L x effy x Nd) / (Ne)
L - delivery speed in m/min
effy - efficiency
Ne - english count
Nd - No of delvieries
(2). P =( L x 1.0936 x 60 x effy ) / (hank (Ne) x 36 x 840 x 2.2045)
P - production in kgs / hr
L - delivery speed in m/min
effy- efficiency
Ne - English count ( number of 840 yards in one pound)
840 - constant
2.2045- to convert from lbs to kilograms
61. MAJOR STUDIES AT AUTOCONER
Splice strength & Appearance
Gauge checking
Machines parameter checking
Loepfe data collection
R/F Bobbin performance checking
SIRO faults collection
Breakage & Speed
62. TWO FOR ONE(TFO)
TFO Breakage
Count & Count CV
Strength & Strength CV
TFO Speed & Other parameters
Uster,IPI & Hairiness
Twist per inch
63. OBJECT IVE OF OPEN END SPINNING
Factors affecting Quality of Open end Spun Yarn
The type and frequency of disturbing yarn faults in Rotor spun yarn dependent
on :
1 Raw material
2 Spinning Preparatory
3 Open end machine setting and maintenance
4 Ambient operating conditions
Raw material
Raw material factors in the order of importance
a) Fibre strength
b) Fibre fineness
c) Fibre length & Uniformity ratio
d) Cleanliness
Fibre strength:
High strength values of individual fibre gives good yarn strength values with
correct amount of yarn twist .
b)
64. Fibre fineness :
It determines both the technical spin limit (that the yarn
count can be spun) and lowest practical twist level . Fibre
fineness determines the number of fibres/cross section of
the yarn . It has been found that the yarn twist can be
reduced without significant loss of strength regardless of
yarn count . Low twist level translate in higher delivery
speeds & higher production translate lower manufacturing
cost but also in softer yarns . Such yarn yield a softer fabric
hand.
A low micronaire value sometimes represents the
presence of immature fibres, which leads to higher nep
counts.
65. CALCULATIONS:
Micronaire value(cotton) : The unit is micrograms per inch. The
average weight of one inch length of fibre, expressed in
micrograms(0.000001 gram).
Denier(man-made fibres): Weight in grams per 9000 meters of fibre.
Micron:(wool): Fineness is expressed as fibre diameter in
microns(0.001mm)
Conversions:
•Denier = 0.354 x Micronaire value
•Micronaire value = 2.824 x Denier
•grams per meter = 0.5905 / Ne
•grams per yard = 0.54 / Ne
•tex = den x .11 = 1000/Nm = Mic/25.4
•Ne = Nm/1.693
•DRAFT = (feed weight in g/m) / (delivery weight in g/m)
•DRAFT = Tex (feed) / Tex(delivery)
•DRAFT = delivery roll surface speed / feed roll surface speed
•No of hanks delivered by m/c = (Length delivered in m/min) /