**Production Calculation for Knitting**

**Raju Tex**

Knitting Technologist, B.J.Group

Chittagong Textile Engineering College

**Facebook:**https://www.facebook.com/ERZRAZU

**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 |

- Machine Guage and Dia
- RPM of Knitting Machine
**Yarn Count**- Stitch Length

**Example 01:**

Find out the production per shift for single jersey and rib from the following data:

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%

**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