Wednesday, 29 April 2015

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Blend Dyeing

Blend Dyeing

Blend Dyeing
Blend Dyeing
In this system the PC or CVC products can be colored at one single shower with scatter and chose direct colors (stable in high temperature and perfect with polyester coloring)- scatter for polyester and direct for cotton. Some immediate colors , for instance , C.I. Direct Black 22 – the pH may be changed in accordance with 8-9 with pop fiery remains.

Fibers may be combined to create a fabric with enhanced properties or to blend a less lavish fiber with a more costly one to acquire a bargain in the middle of value and execution. At the point when more than two or more distinctive fibers are blended personally in a yarn and that yarn is utilized to make a fabric, the subsequent blends is alluded to as a blend. At the point when yarns produced using one fiber are woven with yams produced using another fiber, the fiber sorts are not personally blended and the fabric is alluded to as a union. At the point when fabrics are produced using blends of fibers, four distinct sorts of dyeing impacts may be accomplished.

1. Strong dyeing - both fibers are dyed the same shade and to the same profundity.

2. Reservation - one fiber stays undyed

3. Tone-on-tone - one fiber is dyed a more profound shade than the other.

4. Cross dyeing - every fiber is dyed an alternate and differentiating tint.

Blends of polyester and cotton fibers have gotten to be vital to the textile industry. Cotton gives the stylish and solace properties requested by buyers, while the polyester part adds to execution properties. Luckily, as a result of the amazing contrasts in the dyeing conduct of the two fibers, dyeing blends of these two fibers is genuinely clear. Every fiber may be dyed the same color, or they may be dyed diverse shades. Polyester has no fondness for the vast majority of the classes of dyes used to color cotton, the cellulose being just recolored by scatter dyes. The "Thermosol" process for dyeing polyester was produced by the DuPont organization for the nonstop dyeing of polyester fabrics. This single advancement permitted the quick development of polyester fabrics in the right on time to mid-fifties. The procedure includes padding on the scatter dye together with helpers that minimize movement, drying, then settling the dye in the polyester by dry warming to a high temperatures around 190° – 205°C. During this process the fiber sub-atomic ties open up at these lifted temperatures and the

scattered dyes vaporize and diffuse into the polymer. On cooling, the dyes are caught inside the fiber yielding colored fibers that have great quickness properties. Fitting readiness of the fabric is critical in a constant dyeing operation. For cotton/polyester, the fabric must be totally clean, since leftover oils or earth will be set into the fabric during the Thermosol treatment. The fabric must additionally wet out immediately and consistently to safeguard sufficient ingestion during the padding operation. Favorable circumstances for Thermosol dyeing over customary watery group dyeing systems are: 1. Being nonstop, huge parts can be dyed monetarily. 2. Since no transporter is included, buildups, and speed issues are lessened. 3. Dye obsession is fantastic. 4. Rope imprints are disposed of on the grounds that the fabric is handled in open width. 5. Warmth setting and dyeing may be completed all the while. 6. Dyeability is not influenced by earlier warmth setting. The real inconvenience of this strategy is that long runs of a given shade are important to amplify the full monetary advantage. Some broad data about the procedure may be useful. The dye suspension ought to be homogenized to make it stable. A thickener, generally, sodium alginate at 0.15-0.3 gm/l, is to enhance wet get and to minimize relocation during drying, along these lines disposing of side to side and two sided dyeings (i.e. at the point when the back of the fabric is an alternate profundity contrasted with the face) and radiance impacts around neps and slubs. An anionic wetting operators, e.g., sodium sulphosuccinate at 0.2 gm/l. is added to guarantee quick and complete wetting of the fabric surface. In the wake of padding, predrying and drying, thermofixation is effected at 190° - 205°C for 60-90 seconds to advance complete obsession, penetration, and warmth setting. The cotton dye may be connected from the same shower as the scatter dye. Vat dyes, Sulfur dyes or a Reactive dye can be utilized relying upon the tone and speed needed. In this investigation, a receptive dye will be connected to the cotton fibers in the union fabric, while a scatter dye will color the polyester fibers. Fiber responsive dyes display magnificent wash speed in light of the fact that they are covalently clung to the cotton fiber. This class of dyes was created during the 1950's and keeps on being utilized where incredible wash quickness is needed.

The covalent linkage in the middle of cellulose and a receptive dye may be created by either an acidic or fundamental response, contingent upon the way of the responsive gathering. Most oblige the vicinity of alkali and some warmth to frame the bond to cellulose. Obsession techniques include: • Steaming • Dry warmth (heating) • Air hanging • Wet improvement • Pad(alkali)-clump process If receptive dyes are to be altered by dry warmth, as in the Thermosol process, 50 - 200 g/l urea ought to be added to the pad-shower. "Wet advancement" is infrequently utilized when responsive dyes are utilized as a part of combination with azoic dyes. The pad shower or print glue is arranged with no alkali. In the wake of drying, the fabric is gone into a hot, alkaline arrangement (to settle the responsive dye on the cellulose) containing salt to minimize dying, then washed completely, and dried. The pad-cluster procedure is of worth where no steaming or preparing facilities are accessible. The fabric is padded with dye and alkali, bunched on a roller, wrapped in polyethylene to prevent drying, put away overnight while being pivoted to prevent uneven dyeing, and after that washed and washed. Vast quantities of polyester/cotton blends are dyed in open width by nonstop thermofixation strategies. One arrangement for this methodology is:
1. Pad with dye and "movement inhibitor".
2. Dry.
3. Thermofix.
4. Wash and lessening clear if fundamental.

In the wake of padding and drying, around 30% of the scatter dye holds fast to the surface of polyester and the staying 70% to cotton. During thermofixation, the scatter dye vaporizes and exchanges to the swollen polyester fibers. For most extreme colorfastness, it is attractive to give the dyed fabric either a hot soaping or a warm "diminishment clear" with sodium hydrosulphite and acidic soda to evacuate inexactly held surface dye. On the off chance that this combination of dyes (scatter and responsive) were to be connected by a bunch prepare in a dance or a jet, two stages would be needed. The scatter dye would be connected first at high temperature 130°C with a scattering operators, on the grounds that the receptive cotton dye won't withstand the decrease pass this procedure is completed before the cotton dyeing to evacuate surface scatter dye. After the polyester has been dyed with the scatter dye, the receptive dye would be connected to the cotton fibers and settled, as a rule by the expansion of alkali.
The fabric utilized as a part of this analysis is a blended 50/50 polyester cotton fabric in both weft and warp.

Average Formula for dyeing of Polyester/Cotton blends:

Dispersing agent= 0.5 – 1.0 g/l
Sequestering agent= 1.0 – 2.0 g/l
Levelling agent= 1.0-2.0 g/l
Carrier= 1.0-3.0
Disperse dyes= X%
Selected direct dyes=Y%
Acetic acid (50%)= 0.5-2 g/l
Glauber salt= 5.0 – 20.0 g/l
Temperature= 90- 100
Time = 60- 120 mins
M:L= 1:10

Dyeiing Procedure:

1. Ser the dyebath with substrate at 50 temperature and include scat
tering specialists, leveler, acidic corrosive , bearer and different helpers , then urn the dyebath for 5-10 minutes.

2. Include both colors and raise the temperature to 90- 100 @ 1-2 C/min

3. Include glauber salt and run the shower for one to two bours at the same temperature .

4. Drop down the shower temperature to 70 – 80 more than 10-15 minutes.

5. Dribble the dyebath and bear on the aftertreatment process.

Kicking the bucket of Polyester/Cotton Blends Products:

After Treatment Process:

1. Flush twice with hot and frosty water.

2. Treat the fabric with suitable settling operators for enhancing the wet quickness properties of colored merchandise .

3. Cleanser wash as indicated by merchant proposal.

4. Flush twice with hot and frosty water and after that

5. Neutralize it with acetic acid.

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