Knitting
Production calculation shortcut Formula:
(0.00, 00,005934 × Number of Needle × Number of Feeder × Stitch Length × RPM × 60) ÷ Yarn count. = Production (kg)
Suppose Example:
Number of Needle = 2400
Number
of Feeder = 96
Stitch
Length = 2.85"
Cylinder
RPM = 26
Time
= 60 Minute
Yarn
count = 26/1
(0.0000005934
× 2400 × 96 × 2.85 × 26 × 60) ÷ 26 = 23.38 kg
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Knitting Calculation:
Production
calculation of knitting means calculation of knitting machine production. To
calculate knitting machine production by weighing the total production of one
hour or one shift or one day.
 |
| Knitting machine |
The practical way calculating
production of a machine is as follows. In this method following information for
production calculation are required:
·
Machine
Guage and Dia
·
RPM
of Knitting Machine
·
Stitch
Length
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Knitting Calculation Formula:
Some
important formula of knitting production calculation have mentioned in the
below:
1.
Production in length,
=
Course per minute/ Course per inch,
Or,
=
CPM/CPI
Or,
Number of feeder × cylinder RPM × Time × Efficiency / CPI / 36
2.
Course per inch,
=
Course per minute / production in length
3.
Course per minute,
= Course
per inch × Production in length
4.
Stitch density,
=
Course per cm / Wales per cm
5.
Fabric width,
= {(∏×
diameter of cylinder × machine gauge) / wales per cm}
Or,
=
Number of wales / Wales per cm
Or,
=
Number of needle / wales per cm
6.
Fabric weight,
=
{(Course per minute × yarn length per course) / yarn count}
7.
Needle number of machine,
= ∏ ×
diameter of cylinder × gauge
8.
Yarn length per course,
=
Total number of machine × loop length
9.
Production of single jersey machine in weight (kg) per hour,
∏ × cylinder
dia (inch) × Cylinder RPM × feeder no. × Gauge × stitch length (mm) × tex × 60 ×
efficiency / 1000 / 1000 / 1000
10.
Production of double jersey in length,
=
Single jersey production in length/2
11.
Production of double jersey in weight,
= Single
jersey ×2
Production Calculation of Knitting Machine in
Textile:
Example-01:
If
machine diameter= 20 inch, feeder number= 90, course per cm= 15, machine speed=
25 RPM and machine efficiency is 90% then calculate the production per shift of
a single jersey circular knitting machine.
Solution:
Here,
Diameter
of machine= 20 inch,
Number
of feeder= 90,
Machine
speed or machine cylinder RPM= 25 RPM,
Machine
efficiency= 90%= 0.9,
Time=
1 shift= 8 hours = (8×60) =480 minute
Course
per cm= 15,
Course
per inch (CPI) = (15/0.3937) = 38.10≈38
So,
Production
in meter per shift,
=
No. of feeder × cylinder RPM × time × efficiency / CPI / 36
= 90
× 25 × 480 × 0.9 / 38 / 36
=
710.53 yds.
=
(710.53×0.9144) m
=
649.7 m per shift
So,
production per shift for single jersey circular knitting machine is
649.7m
Example-02:
Calculate
the length in meter of a plain single jersey fabric at 16 courses per
centimeter on a 26 inch diameter and 28 gauge machine having 100 feeders. The
knitting machine operates for 8 hours at 29 RPM at efficiency of 90%.
Solution:
Given
that,
Machine
dia = 26 inch,
Machine
gauge = 28,
Number
of feeder = 100,
Machine
speed or cylinder RPM = 29 RPM,
Efficiency
= 90% = 0.9,
Time=
8 hours = (8 × 60) = 480 minute,
Course
per centimeter = 16,
Course
per inch (CPI) = 16/0.3937 = 40.64 ≈ 41
So,
Production
in meter per shift,
= Number
of feeder× machine speed× time× efficiency / CPI / 36
= 100 ×
29 × 480 × 0.9 / 41 / 36
=
848.78 meter per 8 hours,
=
(848.78 × 0.9144) m
=
776.12 m per 8 hours
So,
production for this calculation stands at 776.12m per 8 hours.
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Example 01:
Find out the production per
shift for single jersey and rib from the following data:
For single jersey,
Fabric width = 53 ", GSM =
150, Yarn count (Ne) = 26S
Stitch length = 2.85 mm,
Cylinder Dia(D) = 25", Cylinder Gauge(G) = 24
No. of feeder = 75, R.P.M of
cyl.= 25, Time =8 hrs, Effi.= 80%
Solution:
Production/8hrs,
πDG X S.L
(mm) X No. of feeder X RPM X 60 X 8 X Efficiency
= ……………………………………………………………………………… kg
2.54 X 36 X 840 X 26 X 2.2046
3.1416 X 25
X 24 X 75 X 25 X 60 X 0.80
= ………………………………………………………………………………kg
2.54 X 36 X 840 X 26 X 2.2046
= 87.85 kg (Ans)
For Rib,
Fabric width = 41", GSM =
460 , Yarn count,Ne = 24S
Stitch length = 2.90 mm,
Cylinder dia,D= 32", Cylinder Gauge,G= 18
No. of feeder = 62, R.P.M.of
cyl.= 15, Time =8 hrs, Effi.= 80%
Production/8hrs,
πDG X S.L (mm) X
No. of feeder X RPM X 60 X 8 X Efficiency X Feeder/course (kg)
= ……………………………………………………………………………................…………
2.54 X 36 X 840 X Ne X 2.2046
3.1416 X 32 X 18 X
2.90 X 62 X 15 X 60 X 8 X 0.80
= ………………………………………………………………….. X
2 kg
2.54 X 36 X 840 X Ne X 2.2046
= 92.22 kg (Ans)
Example 02:
Calculate nominal production of
a single jersey-knitting machine per hour from the data given:
·
Machine
Gauge = 24
·
Machine
Dia = 30 inches
·
Number
of Feeders = 90
·
Machine
RPM = 26
·
Yarn
Count = 24
·
Stitch
length = 4 mm
·
Efficiency
= 85%
Solution:
Step one
First we will calculate number
of needles and number of stitches produced in one revolution. This would help
us in calculating the total length of yarn consumed in one revolution.
Number of needles = Machine dia X Gauge X p
(3.14)
= 30 X 24 X 3.14
= 2260 (Exact 2260.8 but
needles are always in even number so we will take nearest even
figure)
Number of stitches produced in
revolution
Every needle is making one
stitch on every feeder because machine is producing single jersey fabric (full
knit fabric).
Number of stitches produced in
one revolution =
Number of needles X Number of feeders
= 2260 X 90
= 203400
This machine is making 203400
stitches in one revolution.
Step Two
Length of stitch is 04 mm
(stitch length is always calculated in metric system)
From this we can calculate yarn
consumption in yards in one hour
Yarn Consumption (in yards) in
one hour,
Number of stitches
X length of (mm) X RPM X60 (minutes)
= ……………………………………………………………..
1000(to convert mm into meters)
203400 X 4 X
26 X 60
= ………………………………………
1000
= 1269216 meters or
= 1388015 yards
Step Three
In previous step we calculated
quantity of yarn consumed in yards. We can easily calculate weight of this yarn
while its count is known (see example 03).
Weight of cotton yarn,
Length of
yarn
= ……………………..
Count X 840
1388015
= …………………..
Count X 840
= 68.85 pounds or
= 31.23 Kilo grams
Efficiency 85% = 26.55 Kilo
grams
Answer: This machine can
produce 26.55 Kgs fabric in one hour at 85 % efficiency
