1. Introduction

In the textile sector, especially in the preparation of cotton for dyeing and during the dyeing process, calcium, magnesium and iron ions constitute a major obstacle. These ions are removed from the environment by using complexing agents. However, the structure and effectiveness of complexing agents vary depending on their area of ​​use. Commonly used complexing agents are:

• Polyacrylate

• Phosphonate

• Sodium hexametaphosphate

• EDTA

In this study, the comparison of complexing agents with different methods was made, and the three main method is examined in detail:

• Classical Ion Binding Determination: Determination performed with indicator.

• Hamshire Method: Based on the power to prevent calcium turbidity.

• Boiling Down: Based on the principle of lowering the boiling point.

2. Analytical Test Methods and Advantages

1. Classical Ion Binding Determination

Natural hardness is measured using raw water. The pH of the medium is adjusted to 11 with the help of indicator and titration is performed until the color change.

Advantages: It simulates natural conditions in the best way and gives accurate results. The same results are obtained with different calcium salts.

2. Hamshire Method

Pure water is used, after the pH of the medium is adjusted, titration is performed with calcium acetate solution until turbidity occurs.

Disadvantages: Since calcium acetate is not a natural compound, it does not fully reflect the dye bath conditions. It produces relative results.

3. Boiling Down

Hard water and ion sequestrant are boiled together to observe the formation of sediment.

Disadvantages: This method can only evaluate the ability to prevent precipitation; it does not provide information about the ion binding capacity.

3. Ion Sequestrants According to Their Areas of Use

The areas of use of ion sequestrants in the textile sector can be classified as follows:

• Cotton Bleaching: Elimination of fabric stiffness, provision of homogeneous hydrophilicity.

• Reactive Dyeing: Binding of remaining ions after bleaching and elimination of their negative effects on the fabric.

Conditions and Chemicals for Cotton Bleaching:

• Wetting Agent (0.5 – 1.0 g/L)

• Ion Sequestrant (0.3 – 1.0 g/L)

• Oil Remover (0.3 – 1.0 g/L)

• Bracket Preventer (0.3 – 1.0 g/L)

• Peroxide Stabilizer (0.3 – 1.0 g/L)

• Hydrogen Peroxide (2.0 – 4.0 g/L)

• Sodium Hydroxide (2.0 – 4.0 g/L)

Conditions and Chemicals for Reactive Dyeing:

• Temperature: 25-85°C

• pH: 4-11.5

• Electrolyte ratio: 15-100 g/L NaCl

• Alkaline usage: 5-20 g/L soda

4. Effectiveness of Ion Sequestrants in Bleaching Bath

In order for ion sequestrants to work effectively in the bleaching bath:

• The hardness and iron content of the fabric must be significantly reduced.

• Peroxide stabilization must be provided.

• Carbonate and silicate sedimentation must be prevented.

However, tests have shown that some ion sequestrants do not show sufficient effectiveness in high alkaline and temperature conditions. Even the best ion sequestrants can usually only bind 6-8 odH hardness.

Önsuggestion: New generation products with higher binding capacity, stabilization and homogeneous hydrophilicity should be used. For example, the product called DECOWET® BS offers much more effective results than classical ion sequestrants.

5. Conclusion and Recommendations

• For Cotton Bleaching: Indicator The Classical Method provides the most accurate and reproducible results.

• For Reactive Dyeing: Sequestering agents that prevent smudging, have high iron binding capacity and provide homogeneous dyeing should be preferred.

The analysis methods and test procedures suggested in this study are intended to provide more effective production in the textile industry."It can contribute to the provision of resources. In particular, the use of innovative products such as DECOWET® BS can increase process quality and achieve better results."