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.
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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
