DHK™ 189 Heat Stable Desizing Agent
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Use |
Enzyme for high temperature desizing of textile materials |
Properties | – is suitable for desizing at temperatures of 60 - 100° C – is very fast acting at high temperatures – is suitable for the removal of sizes on the basis of potato starch, corn starch, manioc, carboxylmethyl cellulose – very low loss of activity when heated with life steam
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Chemical Characteristic
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Bacterial amylase |
Technical Data |
Appearance : brown liquid Density : approx. 1.1 g/ml pH-value : 5.5 - 6.5 Dissolving procedure: dilute with water Shelf life : 6 months in closed original containers at temperatures below 25° C
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Application
| DHK 189 is used to remove starch and starch-containing sizes from textile material. The high temperature stability of the product permits desizing temperatures of 60 - 100° C. Starch depolymerisation into small degradation products easily removable by scouring occurs in 1 - 2 min. Continuous procedures such as pad-steam procedures, therefore, are possible. For extremely high speeds steam temperatures up to 115° C may be used to extremely fast heat the textile material which has been padded with the enzyme solution. When using DHK 189 the following parameters should be observed : Temperature :Optimum desizing 60 - 90 °C
pH-value : The best activity and stability is at pH 6 - 8. The stability does not depend on the presence of water hardness or salt.
Wetting agents : Most non-ionic products such as DHK 150, DHK 117 or DHK 120 are suitable. Heavy metal ions : Act as enzyme poison and should be sequestered. Setting of the desizing bath : Heat water up to 60 - 90 °C, add and dissolve wetting agent, control pH and adjust with soda ash or acetic acid if required, add DHK 189 by stirring. If it is necessary to store the desizing bath for several hours, the temperature should be kept at approx. 20 °C. Continuous desizing : The fabric is padded with2 ml/l DHK 189 2 – 5 ml DHK 150 or DHK 114 pick-up approx. 100 %, age 2 min at 100 °C, afterwards scour thoroughly with hot water, if necessary add detergent and caustic soda to speed up the washing process. Desizing on the jig Run the dry fabric at 95 - 98 °C into a bath containing 1 - 2 ml/l DHK 189 2 g/l DHK 150 run two ends, drop the bath, scour at highly alkaline pH or bleach. Jeans treatment Jeans usually are treated in rotary drum type washing machines. Desizing is the first processing step : 1 ml/l DHK 189 1 - 2 g/l DHK 116 DHK 117 or DHK 120 15 min / 60 °C
The use of DHK 189 is especially of interest to remove exotic sizes such as manioc starch which are difficult to remove with normal desizing enzymes at 60° C. In the instance temperatures of 70 - 80 °C are recommended. |
