Wholeseller Of Dyes, Chemicals and Auxiliaries
Natural dyes Manufacturer.

 
Home We Are Services Products Query Contact Us Sitemap
 
Direct Dyes 


DIRECT DYES are water soluble substantive dyes. DIRECT dyes cover the entire shade gamut and are easy to apply. They have good leveling property and are cost effective. DIRECT DYES for cellulosics possess excellent light fastness properties. Certain dyestuffs within this range are suitable for high-temperature dyeing of cellulosic/polyester blends. In general, they may be applied on cotton by any method and most of the dyes in the range are even suitable for package dyeing of cotton yarn. DIRECT dyes can also be used to dye jute and coir.

Direct dyes can be used on:

Application

Cellulose

Polyaide

Silk

Leather

Paper

PC blends

Dyeing is normally done in a neutral or slightly alkaline dyebath, at or near the boil, with the addition of either sodium chloride (NaCl) or sodium sulphate (Na2SO4). Also known as hot-water dye, this type can be used with hot tap water and requires no leveling or exhausting agents. It is convenient but lacking in light-fastness and wash-fastness. Direct dyes are used on cotton, paper, leather, wool, silk and nylon. They are also used as pH indicators and as biological stains.

Direct dyes are another class of dyes, one of the two types of dyes that are mixed in 'all purpose' dyes such as Rit. (The other type in the mixture is an acid dye, which will not stay in any cellulose fiber for long.) The colors of direct dyes are duller than those provided by fiber reactive dyes, and the wash fastness is poor - except anything dyed with them to 'bleed' forever. The one advantage is that direct dyes may be more lightfast, that is, resistant to fading in the light, than fiber reactive dyes. The "direct dye" classification in the Color Index system refers to various planar, highly conjugated molecular structures that also contain one or more anionic sulfonate group. It is because of these sulfonate groups that the molecules are soluble in water. Though most direct dyes still can be obtained in powder form, it is increasingly popular to receive them as liquid concentrates. The advantage of concentrates is that they are easy to handle and meter. The disadvantage is that the surfactants and co-solvents needed to keep the dye concentrates stable may interfere with retention and sizing in the case of very deeply colored grades.


Direct dyes are used on cellulose fibers such as cotton, rayon, and linen. They lack the permanence of the cold water fiber reactive dyes which most serious dyers prefer for use on cellulose fibers, but in some cases they have advantages that make their use worthwhile. For example, while many of the direct dyes are not very lightfast, there are some dyes in the class that may be more lightfast than similar shades of fiber reactive dyes. All direct dyes do perform rather poorly with respect to wash fastness. Without an appropriate after-treatment, direct dyes bleed a little with every washing, losing their brightness and endangering other clothes washed in the same load. However, there are special after-treatments which may be used to solve this problem. (Vinegar is not among them! In spite of claims you may see to the contrary, you cannot use vinegar to set any dye on cotton or other cellulose materials.) A product named Retayne, which is an ionic bulking agent which essentially "glues" the dye into the fiber, works very well to make fabric dyed with direct dyes washable without bleeding of the dye.

The name 'direct dye' alludes to the fact that these dyes do not require any form of 'fixing'. They are almost always azo dyes, with some similarities to acid dyes. They also have sulphonate functionality, but in this case, it is only to improve solubility, as the negative charges on dye and fiber will repel each other. Their flat shape and their length enable them to lie along-side cellulose fibers and maximise the Van-der-Waals, dipole and hydrogen bonds. Below is a diagram of a typical direct dye. Note that the sulphonate groups are spread evenly along the molecule on the opposite side to the hydrogen bonding -OH groups, to minimise any repulsive effects.

Shade Card

S. No. SHADES DIRECT DYES
1.   Yellow 3GX
2.   Chrysophaine G (Y)
3.   Chrysophaine G (R)
4.   Orange GR
5.   Viscose Orange BRO
6.   Orange SE
7.   Congo SE
8.   Red 12B (Rose Pink)
9.   Bourdex BW
10.   Green B
11.   Green PLS
12.   Sky Blue FF
13.   Blue 2B
14.   Black BT
15.   Brown MR
16.   Black E (R)
17.   Black E (G)
18.   Turq. Blue
19.   Voilet MB

_________________________________________

Shade Card

S. No. SHADES LIGHT FAST DIRECT DYES
1.   Yellow 5GLL
2.   Yellow RCH
3.   Orange TGLL
4.   Red 5BL
5.   Scarlet 4BS
6.   Sky Blue FB
7.   Blue GLL
8.   Voilet HELIO B

______________________________________

Shade Card

S. No. SHADES MACHING COLOUR DIRECT DYES
1.   Orange S
2.   Mustered
3.   Brown JJ
4.   Brown GG
5.   Sampanji M
7.   khaki 671
8.   Khaki GR
9.   Minerwa Khaki
10.   Olive Green GG
11.   Olive Green URN
12.   Olive GR
13.   Brown T Cone
14.   Parrot Green
15.   Shakuntla Green
16.   Ramba Green
17.   GreenSG
18.   Jade Green 2G
19.   Radha Green
20.   Mahendi Green
21.   Blue GLL
22.   Copper Blue
23.   Voilet BL
24.   Voilet BB
25.   Rose BS
26.   Swis Pink
27.   Rubine CB
28.   Grey RNL
29.   Grey R
30.   Chinku Brown

__________________________________________________________________________________
Please note that the colours on this document are for demonstration purposes only as colours vary with individual monitors and therefore cannot be guaranteed as accurate.

 

 

Copyright (c) 2010 Swetha Traders. All rights reserved.

enqueryenquery enquary enquary enquery