Correct Invoice Weight
The weight obtained after adding standard moisture regain of the material with the oven dry weight is called correct invoice weight or conditioned weight. It is expressed C.I.W.
That is,
CIW = Oven dry weight + Standard moisture regain
Let,
C = The oven dry weight of the consignment
S = The Original weight of the sample
d = The oven dry weight of the consignment
W = The weight of the consignment at the time of sampling.
Now,
d
C = …… X W
S
For samples dried out without cleaning,
100 + R1
Correct Invoice Weight = C [………………]
100
Where R1 is the official allowance for moisture regain.
For samples dried out after cleaning,
100 + R + A + B
Correct Invoice Weight = C […………..........……]
100
Where, (R + A + B) is the total allowance for M.R
100 + X
CIW for blended material = C[………….]
100
Calculation of Correct Invoice Weight of Textile Material
Problem-1:
Calculate the Moisture Regain and Moisture Content of Cotton / Viscose Blend which is having 60% cotton and 40% Viscose in proportion. (Assume necessary details)
Answer:
Assumptions
Moisture Regain for Cotton - 8.5%
Moisture Regain for Viscose - 13%
Moisture regain % of Mixture
= (8.5 * 60 + 13 * 40) / (60 + 40)
= 10.3%
Moisture content % = MR / (1+MR/100)
= 10.3 / (1+0.103)
= 9.34%
Problem-2:
20 tons of 40s Ne 80/20 P/C yarn @ 4% moisture content is shipped. What will be the correct invoice weight? [The official moisture regains of polyester and cotton is 0.4% and 8.5% respectively].
Answer:
20,000 Kg = W + D
Rb = 8.2 * 0.2 + 0.4 * 0.8
= 2.02%
Moisture Content = 4 = [W/ (W+D)]*100
4 = [W / 20,000]*100
W = 4 * 200 = 800 kg
Dry Mass of Yarn = 20,000 – 800 = 19200 kg
Total water allowed WI ,
2.02 = (WI / 19200) * 100
WI = 387.84
Total Invoice Weight = 19200 + 387.84 = 19587.84 kg
