What is the spin plan?

Spin plan calculation means the complete layout of machines and an accurate balance between the production of each machinery. The following information is required for the ring spin plan calculation.

 

Winding section

• Number of machines
• Waste percentage
• Size of machine
• Production efficiency
• Winding speed

Ring section

• Spindle speed
• Number of frames
• Frame size
• Count fed and count delivered
• Hard wastage percentage
• T.M (twist multiplier)
• Production efficiency

Roving section

• Spindle speed
• Number of frames
• Frame size
• Count fed and count delivered
• Hard wastage percentage
• T.M (twist multiplier)
• Production efficiency

Drawing section

• Number of machines
• Number of heads on the machine
• Count fed and count delivered
• Waste percentage
• Machine and production efficiency
• Draft and doubling

Comber and laps former

• Delivery rate
• Production efficiency
• Nips per minutes
• Rate of feed per nip
• Lap weight per yard and sliver hank
• Head and number of deliveries
• Waste percentage or noils

Carding section

• Production efficiency
• Sliver weight per yard
• Waste percentage
• Doffer speed or delivery rate
• Draft

Blow room section

• Number of bales fed per day
• Waste percentage in the blow room
• Bale weight
• Weight per yard of lap
• Length of lap
• Production efficiency
• Shell roll RPM

How do calculate efficiency?

Efficiency is expressed as a percentage with the following formula, output/input. also, actual work done is divided by total work, it is a ratio and expressed in percentage multiplied by 100.

Efficiency%= output work / total work x 100

Further, It is expressed normally with the sign η

Usually, the efficiency and waste percentage removed from high trashy cotton (as an example) are as follows

Efficiency (η )

Winding η=85% ,waste=1%

Ring η =95%, waste =1%

Roving η =95%,waste =0.5%

Drawing η =85%,waste =0.5%+0.5%+0.5%

Card η =85%,waste =6.5%

Blow Room η =85%,waste =6%

Comber η =84%,waste =17%

The details given are in general routine there is no hard and pact rule to accept these standards

Spin plan for 200 bags per day of 20/s carded cotton

Question: we have to produce 200 bags of 20/s in a spinning unit for making hosiery yarn. Plan out the whole spinning machinery to get the required production, including the number of bales needed per day in the blow room.

The waste percentages for different departments are as follows,

e.g.winding η=84% ,waste=1.2%

e.g. ring η =95%, waste =1.15%

Also e.g. roving η =85%,waste =0.6%

And e.g. drawing η =86%,waste =0.5%

e.g. card η =87%,waste =5.5%

e.g. blow room η =85%,waste =6.5%

Winding section spin plan calculation

Production= 200 bags/day

Hence,=20,000 ponds/day

Count       =20 S

Also, efficiency (η)=84%

Firstly, suppose the delivery rate is 1000 meters/minutes

Production per spindle=(1000 X 39.37)/ 36 X (60 X 84 )/( 840 X 20 X 100)

Further, = 3.28 ponds/ hour/spindle

Production of department

P= production per spindle X no. of spindle X number of machines

Suppose the spindle per  machine is 50

Also,⇒20000/(24 x 3.28 x 50 x number of on machines)

Number of machines= 20,000/(24 x 3.28 x 50)

Further, =5.08

As result ≅ 5 machines

Now consider waste =1.2%

So resultant production = 98.8%

Input for winding section= 20,000 x 100/98.8

Hence, =20,243 lbs /day

Ring section spin plan calculation

The output of ring =20,243 lbs /day

e.g. suppose T.M= 3.7 (For Hosiery)

Also, spindle speed =14000 r.p.m

e.g. waste % =1.15%

e.g. efficiency = 95%

O.P.S ( ounces per spindle per shift)=

(14000 x 60 x 60 x 8 x 16 x 95)/(3.7 x  sqrt (20) x 36 x 840 x 20 x 100)

Hence, OPS =10.2

Production of department= o.p.s x 3 x spindles x machines/16

Further 20243=10.2 x 3 x 480 x machines

Number of machines=(20243 x 16)/(10.2 x 3 x 480)

=22.05

Hence ≅22 frames each of 480 spindles

Draft on Ring = count delivered/ count fed

=20/0.8  =25

Assuming Hanks’ roving of 0.8

NOw input for ring =20243 x 100/98.85 (here waste percentage 1.15%)

i-e output of roving=20478.5 lbs /day

Roving section spin plan calculation

e.g. suppose count delivered = 0.8

Also e.g. T.M (twist multiplayer) = 0.78

And e.g. flyer speed =900 rpm

e.g. production efficiency (η)=85%

e.g. waste percentage =0.6%

Production per spindle = 900/(0.78 x sqrt 0.8)X(60 X 85)/(36 X 840 X 0.8 X 100)

=2.72 lbs/hours

Production of roving section = spindle production X number of spindles X number of machines

Suppose the number of spindles per frame = 120

20478.5=2.72 X 24 x 120 X number of machines

Number of machines= 20478.5/(2.72 X 24 X 120)

=2.6

Hence, ≅03 frames each of 120 spindles

Draft on roving frame = count delivered/ count fed

=08/0.128  =6.25

Assuming hanks sliver of =0.128 (i-e =65 grain/yard)

=70/840

Now input for ring =20478.5 x 100/99.4 (here waste percentage 0.6%)

Hence, the output of roving=20602.1 lbs /day

Drawing finisher section spin plan calculation

e.g. suppose sliver =0.128 hanks

Also doubling = 8

e.g. draft =8

e.g. finisher delivery rate = 300 meters per minute

Production efficiency (η)=86%

Waste percentage =0.5%

Production per head =(300 X 39.37 )/36 X ( 60 X 86)/(840 X 0.128 X 100)

=157.45 lbs/hours

Production of draw frame section = number of heads X number of machines X production per head X 24

20602.1 = 2 X 157.45 X 24 number of machines

Number of machines=20602.1/(2 X 157.45 X 24)

=2.72

≅03 Finisher draw frame with double delivery

Drawing breaker section spin plan calculation

The output of breaker = 20602.1 X 100/99.5 ( here waste percentage is 0.5%)

20705.6 lbs per day

Since we have 3 drawings with double-head delivery on the spinning floor, so we calculate the delivery speed

20705.6 =( delivery rate X 39.37)/ 36 X ( 60 X 24 X 85 X 3 X 2)/(840 X 0.128 X 100)

Delivery rate 277.2 meters per minute

The input of breaker= 20705.6 X 100 / 99.5

The input of carding=20809.6 lbs per day

Since doubling and drafting are equal so the weight of the card sliver is 65 grains per yard

Carding section spin plan calculation

Sliver weight = 65 grain /yard

Waste percentage = 5.5%

Production efficiency = 87 %

If doffer speed = 30 rpm

and doffer dia = 27″

Tension draft ( T.D) between doffer and coiler calendar roll (C.C.R)=1.7

Production of card per day=(π x 27 x 30 x 60 x 24 x 87)/(36 x 840 x 0.128 x 100)

=823.62 lbs per day

Number of cards = 20809.6/ 823.62

= 25.26

≅26 cards

Draft = count delivered/ count fed

= weight per yard fed/ weight per yard delivered

=14.5 x 437.5/65

=97.6

Main draft(M.D)= actual draft x (100-w)/100

M.D = 97.6 x (100-5.5)/100

M.D=92.2

Input for carding section=20809.6 x 100/94.5

=22020.74 lbs per day

Blow room section spin plan calculation

Lap weight =14.5 ounces per yard

Efficiency =85%

Waste 6.5%

Shell roll rpm =12 r.p.m

Sheel roll dia= 9″

Paddle roll dia= 2.5″

Production of scutcher=( η x 9 x 12 x 60 x 24 85 x 14.5)/(36 x 16 x 100)

=10454.4 lbs/day

Number of scutchers needed=22020.74/10454.4

=2.10

Nearly one blow room line of 2 scutchers is needed

Input for blow room=22020.7 x 100/93.5

=23551.6 lbs/day

Main draft (M.D)= surface speed of shell rolls/surface speed of the pedal roller

=(π x 9 x 12)/(π x 2.5 x 16)

=2.7

Number of bales each weight =160 kg need

Needed bales = 23551.6/2.2046/160

≅ 67 bales/day

Reverse calculation of spin plan

Spin plan for 214 bags per day of 20/s combed cotton

Q: There is a blow room line with 3 scutchers consuming 80 bales of cotton per day based on 20/S combed cotton hosiery yarn. plan out the rest of the machinery, For consuming material delivered by blow room properly making a good quantity of yarn.

Answer:

Number of bales used=80

Bale weight =168 kg

Packing material weight = 2 Kg

Net cotton weight =168-2=166 kg

Consumption per day=80 x 166 x 2.2046

Further, = 29275.8 lbs/day

Blow room section spin plan

Let’s take one blow room line with 3 scutchers.

For making 20/1 hosiery yarn we take a lap weight of 15.5 ounces per yard

Waste percentage removed = 5.8%

Production efficiency of blow room line=85%

Production of blow room line ponds per day=29275.8 x 94.2/100

=27577.8 lbs/day

Also

Production of blow room line per day with 3 scutchers in a line

=3 x π x 9 x shell roll rpm x 60 x 24 x 15.5 x 85/(36 x 16 x 100)

Or, 27577.8=3 x π x 9 x 60 x 24 x 15.5 x 85 x shell roll rpm/(36 x 16 x 100)

Further, shell roll rpm=27577.8 x 36 x 16 x 100/(3 x 3.1416 x 9 x 60 x 24 x 15.5 x 85)

= 9.87

Hence shell roll rpm ≅ 10 rpm

Carding section spin plan

Let’s there be 30 cards in the mill

e.g. waste percentage =5.5%

Also Production efficiency=86%

But e.g. also sliver weight = 62 grains/ yard

e.g. tension draft = 1.6

Output of card section=27577.8 x 94.5/100

Hence = 26061 lbs/day

Also

Carding out put=(30 x π x 27 offer rpm x T.D x 60 x 24 x 62 x 86)/(36 x 7000 x 100)

Hence 26061=(30 x π x 27 offer rpm x T.D x 60 x 24 x 62 x 86)/(36 x 7000 x 100)

Resultantly doffer rpm=21 r.p.m

Actual draft (A.D)=weight per yard fed/count per yard delivered

A.D=15.5 x 437.5/62

Further, A.D =M.D x 100/(100-W)

Also M.D=109.4 x(100-5.5)/100

As a result=103.4

Lap-former section spin plan

Suppose there are two laps former in the spinning unit running at an efficiency of 87%

Also doubling on lap former=16

Wight of lap produced = 40 penny per yard, as a result, we can say 960 grain/yard

Also, suppose a waste percentage= is 0.88%

So production of lap-former= 26061 x 99.92/100

Hence =26040.15 lbs per day

Also production of lap-former=(2 x delivery rates 39.37 x 40 x 24 x 60 x 24 x 87)/(36 x 7000 x 100)

Further 26040.15=(2 x delivery rates 39.37 x 40 x 24 x 60 x 24 x 87)/(36 x 7000 x 100)

Delivery rate= 69.3 meters/minutes

And also, draft =weight per yard fed x doubling/count per yard delivered

With the result that A.D =(62 x 16)/960 =1.033

Comber section spin plan

Suppose there are 8 combers in the spinning mill each having 8 heads and waste or noils removed is 15%

Firstly Suppose the feeding rate=0.28″/nip

e.g. Production efficiency = 85%

e.g. Weight of sliver per yard= 65 grain/yard

Production of combing section=26040.15 x 85/100

Hence =22134.13 lbs/day

Also comber output=(8 x L x 24)/7000 x (100-W)/100 x n x f/36 x N x 60 x 24 x η/100

Hence 22134.13=(8 x  960)/7000 x (100-15)/100 x 8 x .28/36 x N x 60 x 24 x 85/100

So, nips per minute = 311.6

And also, draft =weight per yard fed /count per yard delivered

Lastly, Draft 960/65=14.77

Drawing and roving section spin plan

Let us suppose there are 3 roving frames in the roving section and 3 finisher draw frames fed by 3 breaker frames all machines have a production efficiency of 84%

Also, the draw frames are double-headed and roving frames having 120 spindles each.

Further waste percentage removed breaker draw frame = 0.3%

Also, the waste percentage removed from the finisher draw frame = 0.2%

And also Waste percentage removed roving or simplex frame = 0.2%

Hence sliver weight =65 grains per yard=0.128

e.g. hanks roving= 0.78

e.g. T.M of roving=0.75

Firstly breaker draws frame D.B

Production of breaker drawing frame=22134.13 x 99.7/100

=22067.73 lbs/day

Also production of breaker section=(Delivery rate x 39.37)/36 x (60 x 24 x 65)/7000 x 6 x 84/100

Further after putting values 22067.73=(39.37 x 60 x 24 x 65 x 6 x 84 x delivery rate)/(36 x 7000 x 100)

Delivery rate D.R = 300 meters/minutes

Finisher draw frame D.F

Production of finisher=22067.73 x 99.8/100

Further=22023.6 lbs/day

Also 22023.6=(6 x 39.37 x 60 x 24 x 65 x 84 x D.R)/(36 x 7000 x 100)

Delivery rate  D.R =300 meters/minutes

Since there is a doubling and draft of 8 so no need to calculate A.D

M.D=(100-0.2) /100  further, M.D =7.98 for finisher

M.D = (100-0.3)/100 further, M.D = 7.976 for breaker

Roving  or simplex frame

Output of roving=22023.6 x 99.8/100

=21979.6 lbs/day

Also, production of roving section= 3 x 120 x flyer speed/(0.75 x sqrt 0.78)x(60 x 24)/(36 x 840 x 0.78) x 84/100

Further, 21979.6=(3 x 120 x 60 x 24 x 0.84)/(0.75 x sqrt 0.78 x 36 x 840 x 0.78) x flyer speed

So, flyer speed=788.6 r.p.m

Hence,≅790 r.p.m

Draft on roving frame= count delivered/ count fed

=0.78/0.128,   i-e =6.094

also M.D = 6.094(100-0.2)/100

= 6.08

Ring section spin plan

Suppose there are 14400 spindles in a spinning unit consisting of 30 frames each of 480 spindles. let the T.M ( twist multiplier) for the hosiery count is 3.6

Let’s say there is 1.5% hard and soft waste in the ring unit. also running  production efficiency of machines is 95%

Production of ring department=21979.6 x 98.5/100

=21650 lbs/day

Also production of ring section= 14400 x spindle speed/(3.6 x sqrt 20) x (60 x 24)/(36 x 840 x 20) x 95/100

Further 21650=(14400 x 60 x 24 x 95)/(3.6 x sqrt 20 x 36 x 840 x 20 x 100)x spindle speed

Further, spindle speed r.p.m = 10700

OPS =(21650 x 16)/(14400 x 3) hence, OPS 8.018

Actual draft on ring= count delivered/ count fed

Hence =20/0.78, =25.64

Main draft = 25.64 x 98.5/100

=25.25

Winding section spin plan

Suppose there are 5 machines each of 60 spindles with a production efficiency of 85%. Let waste percentage by 1% in the winding section

Output of mill= 21650 x 99/100

Production as a result of 21433.5 lbs/day

Also, output of winding section=(delivery speed x 39.37 x 60 x 24 x 60 x 5 x 85)/(36 x 840 x 20 x 100)

Further, 21433.5=(delivery speed x 39.37 x 60 x 24 x 60 x 5 x 85)/(36 x 840 x 20 x 100)

So, delivery rate=900 meters/minutes

Another key point ,Yield percentage=out put/ Input x 100

=21433.5/29275.8 x 100

Finally, the yield is =73.2%

Accordingly production =21433.5 ponds/day

=214.34 bags/day

Also final ops in winding=OPS =(21433.5 x 16)/(14400 x 3) i-e 7.94