ORGANIC STABILIZER AND COMPLEXING AGENT FOR HOT PEROXIDE BLEACHING |
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AVCO-STABIQUEST HS is a synergistic blend of organic stabilizer and complexing agents. Their combination is particularly suited for the stabilization of the peroxide in hot alkaline bleaching baths for bleaching cotton, viscouse and blends with polyester. AVCO-STABIQUEST HS does not contain any silicates, therefore, stabilization can be obtained either with or without the use of silicate. AVCO-STABIQUEST HS is free from surface active substances and is non-foaming.
SPECIFICATION:
PROPERTIES & USES: AVCO-STABIQUEST HS is an organic stabilizer that provides a perfect peroxide stabilization, without the use of silicate. When a high alkalinity and/or elevated temperature becomes responsible for an increased decomposition rate of the hydrogen peroxide AVCO-STABIQUEST HS would slow down such process and make it happen in controlled mode. AVCO-STABIQUEST HS is fortified with specific complexing agent having high complexing capacity towards iron in alkaline bleaching liquors. APPLICATION: Depending on the method applied, 15-20% AVCO-STABIQUEST HS are added, calculated on the amount of peroxide (35%) used. The quantities of alkali and peroxide depend on the kind of pretreatment, the quality of the fabric to be bleached, the process applied, as well as on the time and temperature of the treatment.
When preparing the bleaching liquor, it is recommended to add the ingredients in the sequence in which they are listed in the following recipes. RECOMMENDED RECIPES:
Fully Continuous Processes (with de-sized fabrics)
Semi continuous Processes
High liquor ratio machines
GENERAL INFORMATION:
The following conversion factors relate to the calculation of bleaching liquor recipes:
1 ml H2O2 (35%) = 0.66 ml H2O2 (50%)
1 ml H2O2 (50%) =1.51 ml H2O2 (35%) 1 gr c. soda =2.50 ml caustic soda solution 36 Be'(66.4 Tw) 2.44 ml caustic soda solution 38 Be'(71.4 Tw) 1.64 ml caustic soda solution 45 Be'(91.0 Tw) 1.33 ml caustic soda solution 50 Be'(106.0 Tw) In practical working conditions, a 50 Be’ caustic soda solution is equivalent to a 50% sol.
In order to calculate the concentration of chemicals required in the replenishing liquor for a wet-on-wet impregnation bleach – presuming an almost 100% liquor turnover – the factor F must first be determined according to the following equation:
(L.P.U. after impregnation)
F=____________________________________________________________________ (L.P.U. after impregnation) – (L.P.U. before impregnation) *L.P.U. – Liquor Pick Up The concentration of the replenishing liquor (Cr) is determined by multiplying the desired concentration of the individual chemical (Ci) in the impregnating liquor by factor “F”
Example:
Liquor pick-up after impregnation: 100 %
Liquor pick-up before impregnation: 60 % 100
F = ____________ = 2.5
100 – 60
As a result, the replenishing liquor must be prepared 2.5 times stronger than the concentration in the impregnating liquor.
Cr= concentration of the replenishing liquor (F x Ci)
F= 2.5 Ci=10 ml/l chemical (quantity assumed) Cr = 2.5 x 10 = 25 ml/l product As a result of this example, the replenishing liquor must contain 25 ml/l of the chemical.
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