Sequestrants & Dispersants
The main function of these auxiliaries is to sequester metal ions that can have harmful effects upon fabric processing such as rapid peroxide breakdown due to iron contamination leading to pinholes in fabrics. An assessment of the basic properties of these compounds is to evaluate the effectiveness of their sequestering properties using an Iron sequestration test. The ability of the product to perform its function can be seen by the resultant filtration and assessing the amount of iron which has not been sequestered. This is usually indicated by precipitated specs of iron oxide.
There are many sources of calcium in textile wet processing, the most common being its presence in the fabric itself and in the water supplies utilised for bleaching, dyeing and washing off / rinsing. Calcium has a huge impact if present in reactive dyeing systems, it can influence;
- Solubility
- Fixation efficiency
- Rub fastness
- Migration properties
- Wash fastness
- Level dyeing properties
- Substantivity
The use of sequestrants and dispersants are widely employed to combat these negative effects, some factories use the German hardness scale whereby 1 degree of hardness is equivalent to 17.80 parts per million of Calcium carbonate. Some factories can encounter large amounts of Calcium salts up to 20 degrees German hardness which is equivalent to 356 ppm CaCO3. Texchems range of sequestrants caters for the majority of processing routes to combat a large range of harmful metal ions.
Core Products
| Product | Key Properties |
|---|---|
| Texassist A30 | Surfactant free, polymeric chelating agent |
| Texassist ARC 200 | After clear / wash-off agent for reactive dyed fabrics |
| Texassist DAC 150 | After Clear agent for various processes |
| Texassist HDS New | Zero foaming highly concentrated sequestrant & dispersant |
| Texassist NFP 400 | Supreme, highly active, multi-stage versatile sequestrant |
| Texassist IS-G | Highly Cost Effective Iron Sequestration |
| Texassist S700 | Concentrated, powerful sequesterant for use in various processing stages |
