Discharge Able Reactive Dyes 4755e

Discharge Printing Pre-Conditions For Fabrics To Be Printed There are 3 basic conditions a fabric must possess to be considered for today's Unit Print or T-Shirt Print market. These are: 1. Uniformity in Print Bottom. 2. Dischargeable to Sulfite Based Discharging agents. 3. Dyed Bottom Compatibility with Print Vehicle. The first point includes such considerations as uniform washing and scouring, the use of "print friendly" add-on (softeners, wetters, resins, etc.), and uniform absorbency. The second point describes the pre-dying step and the fact that dye selection for shade matching must include the behavior of the dyed fabric after finishing. The print vehicle at use in the majority of the T-Printers contains solvents and emulsifiers which will have an affinity of the dyes on the fabric. The Dyeing process for reactive dyes includes a washing step to remove the excess dye. However, subsequent finishing with acid products can cause certain reactive dyes to release some of the fixed dye and this would then "Bloom" into the print due to the heat of curing and fixing of the print. The Remazol® Reactive dyes are not effected by the acid treatment and would not be subject to breakdown in this manner. The other dye classes for cotton such as direct, sulfur, vats and pigment are more prone to exhibit a tendency to bloom than the reactive dyes. In the case of Polyester or Polyester/Cotton blended fabrics the polyester dye must be dyed without carrier and given a good reductive scour or some disperse dye remains on the cotton and all disperse dyes are soluble to some extent in the solvent of the print vehicle. The phenomenon of dye transport in the fiber is a reversible physical/chemical reaction Û. This means that even with a good dying procedure, dye will return to the surface of the fiber and be accessible to the print vehicle after any heat processing (drying, etc.). The fact that the dying process is not a guarantee of a print-friendly mandates the selection of dyes based on solubility in the print vehicle. Some of this information is known but testing of existing shades should be done. The dyeing for testing should always be made on the Polyester/Cotton fabric in the absence of the cotton dye but the fabric should be subjected to the Cotton dye procedure. The third point is dichargeability of the Cotton dye. The most popular and used dyes for the cotton fabrics are the reactive dyes. Not all reactive dyes are dischargeable completely and there must be a selection of dyes used to match shades that are to be marketed as dischargeable. As a group, the Remazol® fiber reactive dyes offer the widest selection for this criterion. I am incorporating some information concerning Remazol® dishargeability and the process at this point.

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REMAZOL® DYES: DISCHARGE and RESIST The terminology used to describe these two processes is sometimes confusing to the Textile Industry. The first order of business,then, has to be a definition and description of these two processes. RESIST Resist is the term used to describe the Prevention of the Dyeing Process brought about by the application to the fabric of a Mechanical, Physical or Chemical Substance to prevent Dye Access to the Fabric. This done in such a manner that a Pattern is realized in the Dyed Goods. DISCHARGE Discharge is the term used to describe the displacement of a dyed shade by a Chemical Process in such a manner that a pattern is imparted to the dyed fabric. The fabric is Dyed First. The Discharge Agent is applied to the fabric normally by Printing. The fabric is processed to get the discharge. Then the fabric is Washed to remove the Byproducts of Discharge. If color is added to the Discharge Agent, this is the Illuminating or Discharge Color. If No color is added to the Discharge Agent, the result is a White Discharge. The most common Discharge Agents are chemicals based on Sufoxylate Formaldehyde Chemistry. DISCHARGE AGENTS The most common Discharge Agents are chemicals based on Sufoxylate Formaldehyde Chemistry. Sodium Sulfoxylate Formaldehyde * Vat Discharge Zinc Sulfoxylate Formaldehyde * Pigment & Acid Sodium Hydro Sulfite Potassium Sulfoxylate Formaldehyde Thiourea Dioxide Compounds * Hypo Chlorites are also used for specific articles

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REMAZOL® DYES: DISCHARGE D I S C H A R G E: Reaction Mechanism Typical VS (Remazol®) Dye in Linkage to Cellulose

Discharge Agent º º º º º ↓

º º º º º ↓

R1 - N = N - R2 - S O2 - C H2 - C H2 - 0 - CELLULOSE º º º º º ↓ Color Destruction

º º º º º ↓ Linkage Destruction

Cleavage products that must be removed by washing to get to the final shade are left on the fabric. These may be amides that are easily saponified and removed by washing. They may or may not be colored themselves.

R1 - N - H2 + H2 - N - R2 - S2 O - C2 H - C H - H + H0 - CELLULOSE Decomposition Products

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REMAZOL® DYES FOR DISCHARGE PRINT: GROUND SHADE PRODUCTION The following Remazol® Dyes are dischargeable by either the alkaline or the acid Sulfoxylate Formaldehyde Procedures. The maximum concentration of dye used to make a shade match affects the discharge obtainable. The maximum recommended amounts of each Remazol® Dye are included. This list should be used for all dyeing that requires that the shade be dischargeable. The most trouble free dyes for this procedure are marked by *. REMAZOL® Dye

Discharge

Max.Conc.

GOOD

Br. Yellow 4GL Br. Yellow GL Gold. Yellow RNL Gold. Yellow 3RA Br. Orange 3R Br. Red F3B Br. Violet 5R Blue BB Orange BN Turquoise Blue GA Navy RGB Navy GG Black B Black GF-A Deep Black RGB Night Black RGB

Yes yes yes yes yes yes yes yes yes partial yes yes yes yes yes yes

50 g/l 50 g/l 50 g/l 50 g/l 50 g/l 60 g/l 30 g/l 30 g/l

* *

15 g/l 60 g/l 60 g/l 80 g/l 80 g/l 80 g/l 80 g/l

* * * * * * * *

*Red FLM is not recommended for exhaust. It is recommended for B or Continuous. All Turquoise Dyes are very difficult to discharge and should not be recommended for this procedure. The exception is in cases where Turquoise is needed for Green shades. Shade discharge is dependant on the dyestuff used and NOT the Technique used to make the dyeing.

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REMAZOL® DYES Selection For Dischargeable Shade Production Black

Remazol® Black B Remazol® Black NF Remazol® Deep Black RGB Remazol® Night Black RGB Remazol® Navy R-GB Remazol® Golden Yellow RNL Remazol® Orange BN Remazol® Brill. Red F3B

Navy

Remazol® Black B Remazol® Navy Blue R-GB Remazol® Brill. Red F3B Remazol® Orange BN Remazol® Navy GG

Dark Green

Remazol® Orange BN Remazol® Navy RGB Remazol® Navy GG Remazol® Brill. Blue BB New

Blue

Remazol® Brill. Blue BB New Remazol® Navy RGB

Royal

Remazol® Brill. Blue BB New Remazol® Brill. Red F3B Remazol® Brill. Violet 5R

Turquoise

Remazol® Turquoise G-A Maximum 1% :: 10 g/l Remazol® Brill. Blue BB New Remazol® Navy RGB

Bright Green

Remazol® Brill. Yellow 4GL Remazol® Brill. Blue BB New

Teal

Remazol® Brill. Yellow 4GL Remazol® Brill. Blue BB New Remazol® Navy RGB Remazol® Navy GG

Bright Red

Remazol® Brill. Red F3B Remazol® Golden Yellow RNL

Red

Remazol® Brill. Red F3B

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REMAZOL® DYES Selection For Dischargeable Shade Production (Cont.) Wine

Remazol® Brill. Violet 5R Remazol® Brill. Blue BB Remazol® Brill. Red F3B

Maroon

Remazol® Brill. Violet 5R Remazol® Brill. Orange 3R Remazol® Orange BN Remazol® Brill. Red F3B

Violet

Remazol® Brill. Violet 5R Remazol® Brill. Red F3B Remazol® Brill. Blue BB New

Scarlet

Remazol® Brill. Red F3B Remazol® Brill. Yellow GL

Orange

Remazol® Brill. Orange 3R Remazol® Orange BN

Golden Yellow

Remazol® Golden Yellow RNL

Lemon Yellow

Remazol® Brill. Yellow 4GL

Note that the bright royal shades and the shades requiring the use of a turquoise dye are difficult to match with the available dyes.

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The use, even very sparingly, of both the Remazol® Turquoise G-A and the Remazol® Brilliant Blue R Special is not recommended if a consistently dischargeable bottom is desired. It is customary for these shades to be matched either for discharge but slightly dull or for optimum brightness but not dischargeable. Any shade can be matched using the list of dischargeable dyes and a reasonable result will be obtained. The listing by shade groups insures the most reliable results from a performance view point. This listing and grouping is far from a complete dictionary for dyeing and discharge but is our experience. The use of dischargeable direct dyes would be similar in shade grouping but the resultant problems with the dye diffusion into the solvent in the print vehicle would be greatly increased.

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