Conversion of percentage on weight of
fabric to grams per liter.
In long liquor ratio systems e.g., winches, chemical calculations are
given on a weight per unit volume basis e.g., grams/liter, but at short
liquor ratios, e.g., kiers, the concentrations are normally given in
percentage on weight of fabric (% o.w.f).
Provided that the liquor ratio (LR) is known, the two units can be
inter converted using the following relationship:
Concentration (g/l) = (% o.w.f. X 10) / LR
or
Concentration ( % o.w.f.) = [(g/l) X LR] / 10
Example: 4.5% Hydrogen Peroxide (35% w/w) is required to bleach a
cotton polyester fabric on a kier at a liquor ratio 4:1. What
concentration, in g/l of peroxide should be made up?
Calculation concentration = (4.5 X 10) / 4 = 11.25 g/l H2O2, 35% w/w
Example: 5 g/l caustic soda is used at 5:1 liquor
ratio. What is the percentage, on weight of fabric?
Calculation: Concnentration = 5 x 5 /10 =
2.5%
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