Calculation of Loom and Weaving Shed Efficiency in Weaving
Efficiency:
Efficiency depends on the amount of time lost due to loom stoppages. Less the production loss due to loom stoppages more is the efficiency. In general, the factors on which production depends are also responsible for the efficiency.
Efficiency,
Actual production
= ….......…………………… × 100%
Calculated production
3
= ……… × 100
4
= 75%
Where, 4 yds and 3 yds are calculated and actual production respectively of a loom.
Efficiency may be calculated under the following heads:
Running Efficiency:
It does not take into account such stoppages as for cleaning etc.
Overall Efficiency:
It takes into account such stoppages as for cleaning etc. and so it is lower than the running efficiency.
Shed Efficiency:
It takes into account the looms stopped say, for want of warps suitable for them for a week or so or for other causes, say for a day or two or more.
Example 01:
A loom making 216 picks per minute produced 254.5 yds of cloth in a week of 54 working hours. During the week the loom remained stopped one hour for cleaning. If picks per inch in the cloth are 60, calculate the running efficiency of the loom.
Solution:
The actual running hours of the loom to be taken into account,
= 54 - 1 = 53 hours.
The calculated production in 53 hours,
= 53 × 216 × 60
= 686880 picks.
Actual picks obtained in 254.5 yds,
= 254.5 × 36 × 60
= 549720 picks.
Therefore, efficiency of the loom,
549720 × 100
= ………………….
686880
= 80%
So, the running efficiency of the loom is 80%.
Example 02:
Calculate the length of the cloth produced in hours on a loom which makes 200 picks per minute. The picks per inch in the cloth are 80 and the loom has an efficiency of 78%.
Solution:
Actual production = Calculated production × Efficiency
Total picks × Efficiency
= …………………………………..
Picks per inch in the cloth × 36
200 × 60 × 9 × 78
= ………………………
80 × 36 × 100
= 29.25 yds
= 29 yds 9 inches.
So, the length of the cloth produced in hours on a loom is 29 yds 9 inches.
