Helo, gys today I m going to explain about acid dyeing, list of dye, Properties, wool dyeing process and advantage. i m writing all information in this article with my personal view. so, read complete article
Industrial information of Acid dyeing
If we compare between the acid dye and basic dye then the first difference is solubility, light fastness properties etc. acid dye have highly soluble in water compare with basic dyes. and acid dye have good light fastness Properties compare with basic dyes.acid dyes is more use for protein fibers such as wool, silk, acrylic and nylon. and these proteins fibers contain sulphonic acid groups. Dye solubility increase in water with the help of sulphonic acid groups. and it’s gives dye molecules Negative charge and fibre are given the positive charge and this both charge make more intrects with the dye properly. This process is indicated ionic interaction and this process is possible with some especial forces such as Vander Waals and hydrogen bonds because both force is formed between the fibre and dyes.
List of acid dyes
• Acid yellow 4R
• Alizarine cyanine green G
• Nentlen Black C
• Nentlen Nevy Blue RL
• Acid Red GTR
Properties of acid dyes
- Acid dyes are highly soluble in water compare with basic dyes.
- Acid dyes is properly work on proteins fibres such as wool, silk, nylon.
- Acid dye have no effinity for cellulosic materials. Hence, acid dye is not suitable for cellulosic materials.
- Acid dyes is more suitable and profitable for proteins fibres such as silk, wool, nylon and acrylic.
- Acid dyes are properly ionic in nature.
- Acid dyes is more react on to the proteins fibres with the help of Vander Waals and hydrogen bonds because it’s formed between fibre and dyes.
- Light fastness is good compare with basic dyes.
- In case of acid dyes, uses strong acidic to netural PH bath.
- Acid dyes is more effective for proteins fibres.
- Acid dye is not able to dyeing of cellulose materials.
Classification of acid dyes
• levelling dyes
• milling dyes
• super milling dyes
Important dyes is used for wool dyeing process
• BEMACID CA (half milling agent)
• BEMACID CM ( milling agent)
• Very good wet fastness and masking properties and light fastness is also good.
Role of pH in acid dyeing
• pH depend upon quality of dyes
• fixation, absorption and exhaustion all are depend upon pH.
• pH boost absorption or fixation.
• role of pH is also depends upon the quality of dyes if quality is not proper then fixation is not properly work on to the materials.
• don’t used low pH and high pH because it increases chances of damage for materials. So maintain pH depend upon materials.
Role of Glablur salt
• don’t used more goloblur salt in solutions it effects on rubbing fastness.
• it is also called levelling agent.
Effect of temperature on proteins fibres such as wool materials.
• If dyeing process is carried out at boiling temperature then no chances of damaged for wool materials they are always protected wool materials.
• But if dyeing process is carried out at high temperatures then the chances of dye stuff diffuse faster in to the materials and gives good pantration and make better shade and make good fastness properties but if dyeing time will increase with high temperature then the chances of damaged for wool materials.
Dyeing of wool with acid dye
Acid dye is more suitable or profitable for proteins fibres such as, Wool dyeing, silk dyeing and acrylic dyeing. Acid dye is also called ainonic dyes. acid dyes has no more affinity for cellulosic materials so acid dyes is used for cellulosic materials. Because poor shade, poor fastness properties will occur after dyeing. But acid dyes is regularly or industrial used for proteins fibres such as wool, silk, acrylic etc. In this case good light fastness properties will occur after dyeing.
Wool dyeing process
First off all put the all recipe in bat then after 5 mint again put the sample or materials in dyeing bath and after 5 mint raised the temp at 100°C and continue Dyeing is done for 30-60 mint at 100°C.after dyeing cool – drain- cold wash-soaping with no ionic soap solutions at 60°C for 20 mint. Again wash with hot water and dry the sample. This is the complete process of wool dyeing.