Procion Reactive Dyes in Textile Printing
Part 3: Fixation Methods for Procion Printed Fabrics
In Part 1, we understood what Procion reactive dyes are, their types, and how printing paste is prepared. In Part 2, we discussed one-stage and two-stage printing processes, alkali timing, paste stability, resist salt, and discharge control.
Now we come to the final and most practical part:
In textile printing, applying the colour on the fabric is only one part of the process. The real success of reactive dye printing depends on proper development or fixation.
If the dye is not properly fixed, the printed colour may look good initially but may wash out later.
What Is Fixation in Procion Dye Printing?
Fixation means making the dye react with the fibre so that it becomes permanently attached.
In the case of Procion reactive dyes, fixation happens when the dye reacts chemically with cellulose fibre under suitable conditions of:
- Alkali
- Moisture
- Heat
- Time
This is why printed fabric is not simply dried and finished. After printing, it has to be passed through a suitable development process.
Printing places the colour on the fabric. Fixation attaches the colour to the fibre.
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Main Methods of Developing Procion Prints
After printing and drying, Procion printed fabrics may be developed by any one of the following methods:
- Steaming
- Baking
- Flash ageing
- Air-hanging
- Vat development
- Pad alkali–batch process
Each method has a different way of providing the required conditions for dye-fibre reaction.
1. Steaming Process
Steaming is one of the most important methods for developing Procion printed fabrics.
In this process, after printing, the fabric is first dried. It is then exposed to steam for a specific time. The steam provides moisture and heat, which help the reactive dye bond with the cellulose fibre.
Steaming Conditions
For fabrics printed with Procion-H and Procion-Supra dyes, the fabric is kept in steam for:
For fabrics printed with Procion-M dyes, the fabric is kept in steam for:
After steaming, the printed fabric is washed to remove unfixed dye and other chemicals. For viscose fabrics, moist steam is necessary.
Why Steaming Works
Reactive dye fixation needs moisture. Steam supplies moisture and heat together. This helps the dye move into the fibre and react with cellulose.
Steaming is especially useful for Procion-H dyes because they are less reactive and need proper fixation conditions.
2. Baking Process
Baking is another method used for developing Procion printed fabrics.
In baking, heat is supplied in dry form. Because moisture is less available compared to steaming, the recipe usually contains a higher amount of urea.
Urea helps retain moisture and supports dye fixation during heating.
Urea in Baking
When baking is used, the amount of urea is generally kept higher.
Alkali Used in Baking
For printing with Procion-H, the paste may contain:
For printing with Procion-M, the paste may contain:
After printing, the fabric is dried and then baked under suitable conditions.
Baking Conditions for Procion Printed Fabrics
| Dye Used | Cotton Temperature | Cotton Time | Viscose Temperature | Viscose Time |
|---|---|---|---|---|
| Procion-Supra | 140°C | 5 minutes | 150°C | 5 minutes |
| Procion-H | 140°C | 5 minutes | 150°C | 5 minutes |
| Procion-M | 110°C | 3 minutes | 140°C | 3 minutes |
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3. Flash Ageing Process
Flash ageing is a rapid development process. It is completed in two stages and is used for quickly fixing selected Procion dyes on cotton and viscose fabrics.
This process is based on the pad-steam method.
How Flash Ageing Works
- The fabric is printed with a paste containing Procion dye and thickener, but without alkali.
- The printed fabric is dried.
- The fabric is padded with a cold alkaline solution containing salt.
- Immediately after padding, the fabric is passed through a steamer.
- The dye is rapidly fixed.
The key point is that alkali is not present in the original printing paste. It is applied later. This improves paste stability and printing quality.
Advantages of Flash Ageing
- Since there is no alkali in the printing paste, printing quality is improved.
- Fixation is completed in a very short time, about 40 seconds.
- Printed fabric can be stored before development because alkali has not yet been applied.
Flash Ageing Printing Paste Recipe
| Ingredient | Quantity |
|---|---|
| Urea | 50 parts |
| Water | 580–510 parts |
| Procion dye | 10–80 parts |
| Sodium alginate | 350 parts |
| Resist salt | 10 parts |
| Total | 1000 parts |
In this recipe, urea is warmed with water. For Procion-H dye, it is heated up to about 90°C. For Procion-M dye, it is heated up to about 70°C. The dye is then added and dissolved with continuous stirring. After this, sodium alginate containing resist salt is added and mixed thoroughly.
Padding Solution for Flash Ageing
| Ingredient | Quantity |
|---|---|
| Magnesium metasilicate | 100 parts |
| Anhydrous sodium carbonate | 150 parts |
| Anhydrous potassium carbonate | 50 parts |
| Sodium chloride | 100 parts |
| Water | 500 parts |
| Gum | 100 parts |
| Total | 1000 parts |
4. Air-Hanging Process
The air-hanging process is a simple method of developing Procion printed fabrics. It does not require large equipment, which makes it attractive in situations where steaming or baking facilities are not available.
However, it has one important limitation:
Air-Hanging Method
- Pad the unprinted fabric with 2% soda ash and dry it.
- Prepare Procion dye paste without adding alkali.
- Print the soda-ash-treated fabric with this alkali-free paste.
- Keep the printed fabric in air for several hours.
If the atmosphere is warm and humid, the results are better because reactive dye fixation needs moisture.
5. Vat Development
In vat development, the printing paste is prepared without alkali. After printing, the fabric is dried and then passed through a warm alkaline solution.
This method also follows the principle of keeping alkali separate from the printing paste.
Alkaline Solution for Vat Development
| Ingredient | Quantity |
|---|---|
| Caustic soda, 38°Bé or 70°Tw | 60 parts |
| Sodium carbonate, anhydrous | 150 parts |
| Potassium carbonate, anhydrous | 50 parts |
| Sodium chloride | 100 parts |
Water is added to make the total 1000 parts. This solution is warmed to 95–98°C.
6. Pad Alkali–Batch Process
The pad alkali–batch process is useful where steaming and baking facilities are not available.
In this method also, the fabric is printed with a paste that does not contain alkali. After printing, the fabric is padded with sodium silicate solution. Then the fabric is batched without drying.
Sodium Silicate Solution
| Property | Value |
|---|---|
| Ratio by weight, SiO2 : Na2O | 2.0 |
| Specific gravity at 20°C | 1.5 |
| Viscosity at 20°C | 200 centipoise |
Batching Time
| Dye Type | Batching Time |
|---|---|
| Procion-M | 10 minutes |
| Procion-Supra or Procion-H | Up to 3 hours |
To prevent the fabric from drying, it is covered properly with a polythene sheet. After batching, the fabric is washed thoroughly and dried.
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Comparison of Fixation Methods
| Method | Main Principle | Alkali Position | Suitable Situation |
|---|---|---|---|
| Steaming | Moist heat fixation | Usually in paste | When steaming equipment is available |
| Baking | Dry heat fixation | Usually in paste | When baking equipment is used |
| Flash ageing | Alkali padding followed by rapid steaming | Applied after printing | Fast fixation and better paste stability |
| Air-hanging | Alkali on fabric, development in air | Applied before printing | Simple method, warm humid air helpful |
| Vat development | Warm alkaline treatment after printing | Applied after printing | Alkali-free paste and later development |
| Pad alkali–batch | Sodium silicate padding and batching | Applied after printing | Useful when steaming/baking is unavailable |
Washing After Fixation
After fixation, washing is essential. The purpose of washing is to remove:
- Unfixed dye
- Thickener
- Alkali
- Salts
- Other auxiliaries
If washing is not done properly, the fabric may show poor washing fastness, staining, harsh handle, or shade dullness.
In reactive dye printing, washing is not a minor finishing step. It is part of the quality of the final print.
Practical Notes for Textile Students
The six fixation methods may look different, but they all aim to achieve the same final result: the dye must react with cellulose fibre.
The difference lies in how each method provides alkali, moisture, heat and time.
- Steaming provides moist heat.
- Baking provides dry heat, supported by higher urea.
- Flash ageing applies alkali later and fixes quickly.
- Air-hanging uses alkali-treated fabric and atmospheric moisture.
- Vat development uses a hot alkaline bath.
- Pad alkali–batch uses sodium silicate padding and controlled batching.
Once this logic is understood, the methods become easier to remember.
Common Mistake
A common mistake is to think that once fabric is printed and dried, the process is complete.
It is not. In Procion reactive dye printing, drying only removes water. It does not necessarily fix the dye completely.
Fixation requires the correct combination of alkali, moisture, temperature and time.
Knowledge Nugget
All fixation methods are different ways of answering the same question:
How do we create the right conditions for the Procion dye to chemically bond with cellulose?
That is the heart of reactive dye printing.
Reflection Question
Why can pad alkali–batch processing be useful where steaming and baking facilities are not available?
Because the fabric can be printed without alkali, padded later with sodium silicate, batched under covered conditions, and then washed and dried after fixation.
Final Summary
Procion reactive dye printing is successful only when the dye is properly fixed on the fibre. The main fixation methods include steaming, baking, flash ageing, air-hanging, vat development and pad alkali–batch processing.
Each method has its own logic, equipment requirement and suitability. The printer must choose the method based on dye type, fabric type, available machinery, paste stability and production conditions.
Printing gives the design, but fixation gives durability.
Without proper fixation, even a beautiful print may fail during washing.
Disclaimer and Safety Note: This article is intended for educational and informational purposes only. The recipes, chemical names, quantities, temperatures and process conditions mentioned here are provided to explain the principles of Procion reactive dye printing and should not be treated as direct instructions for unsupervised practical use. Textile printing involves the use of dyes, alkalis, salts, thickeners and other auxiliary chemicals, which should be handled only with proper knowledge, suitable safety precautions and appropriate supervision. Before using any chemical, always refer to the latest supplier technical data sheet, safety data sheet and applicable local regulations. Use appropriate personal protective equipment, ensure good ventilation, safe storage, careful measurement, spill control and responsible disposal of chemical residues and wastewater. The author and publisher do not accept responsibility for any loss, damage, injury or environmental harm arising from the direct or indirect use of the information given in this article, and readers are advised to consult trained textile processing professionals before attempting any laboratory or industrial application.
Goyal, P. Procion Reactive Dyes in Textile Printing -Part 3: Fixation Methods for Procion Printed Fabrics. My Textile Notes. Available at: http://mytextilenotes.blogspot.com/2026/05/procion-reactive-dyes-in-textile_12.html
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