## Tuesday, August 9, 2011

### Calculate nominal production of a single jersey-knitting machine per hour:

Learn Apparel Merchandising, Learn Fashion design.
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 * gauge * p (3.14)
= 30* 24*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 feeders because machine is producing single jersey fabric (full knit fabric).
Number of  stitches produced
in one revolution = Number of needles * number of feeders
= 2260*90
= 203400
This figure shows that 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 figure we can calculate yarn consumption in yards in one hour

Yarn Consumption (in yards) in one hour
= number of stitches * length of (mm) * RPM *60 (minutes)
1000(to convert mm into meters)

=203400 * 4 * 26 * 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 * 840

= 1388015
840 * 24
= 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

Thanks