What is bifunctional reactive dyes?
Bifunctional reactive dyes are coloured compounds that have more than one reactive moiety per molecule or groups capable of forming covalent bonds between carbon atom of the dye ions or molecules and functional groups of the substrate. This is due to effective penetration and efficient dye fixation with cotton fabrics.
What is meant by reactive nature of dye?
Reactive dyes form a new chemical compound when they come into contact with a fiber molecule. Reactive dyes are applied either from a solution with high pH or from neutral solutions that are later alkalized through a separate process. Sometimes different shades are brought out by applying heat to the dyed textile.
What are reactive colors?
In a reactive dye, a chromophore (an atom or group whose presence is responsible for the colour of a compound) contains a substituent that reacts with the substrate. Reactive dyes have good fastness properties owing to the covalent bonding that occurs during dyeing.
What is the difference between reactive dye and pigment dye?
Reactive dyes do just that- react. The reactive dye particles form a covalent bond with the fabric and essentially stain it the desired color. Pigment dyes on the other hand, are insoluble molecules that sit on top of the fiber. No chemical reaction takes place.
Why do dyes have different Colour strengths between batches?
Why do dyes have different colour strengths between batches? Dye manufacturers mix the dyes with other compounds which are not colorants to give them various properties. The proportions that are added are not always identical from batch to batch.
What are the examples of reactive dyes?
Reactive dyes
| Chemical Name | CAS | MF |
|---|---|---|
| Reactive Brown 2 | 12236-93-0 | C31H20ClN9Na4O12S4 |
| Reactive Blue 74 | 12677-16-6 | C28H23ClN6O9S2.2Na |
| Reactive Orange 5 | 70210-21-8 | C26H17ClN7Na3O10S3 |
| PROCION YELLOW H-E3G | 59112-78-6 | C52H34Cl2N18O20S6.6Na |
Is reactive dye natural?
Fiber Reactive dyes are the ONLY dyes that this is true of. Natural dyes from plants and insects are not permanent. Some of the mordants used to make natural dye react, such as tin and chromium, are toxic themselves, although the mordant Alum is safest and most common. A raspberry dye bath.
How do you use Dharma pigment dye?
Just dilute it to taste (we recommend 1 part pigment to 2-4 parts water), apply it, and let it dry and air-cure for at least 24 hours. (If a 24-hour air cure is a problem for you, you can speed up the process with a hair dryer.)
What is exhaustion of dye?
The degree of dye bath exhaustion is therefore a function of time describes the rate and extent of the dyeing process. For a single dye, the exhaustion is defined as the mass of the dye taken up by the material divided by the total initial mass of dye in the bath.
What are the requirements for selecting compatible dyes?
Compatible dyes are dyes which build up on shade in that they increase in depth as the dyeing progresses to one single shade. Incompatible dye mixtures build up off shade making shade matching very difficult. The dye supplier should be able to specify which dyes in his range are compatible.
