Disperse Dyes for Dyeing and Printing

Disperse dye can be used with various techniques and will readily colour synthetics such as polyester, nylon, cellulose acetate, vilene, viscose, synthetic velvets and PVC. They can also be used to colour plastic buttons and fastenings. Their effect is less potent on polyester, due to the molecular structure, allowing only pastel through to medium shades. Polyester fibre contains pores or canals within its structure which, when heated to 100°C, expand to allow particles of the dyes to enter. The expansion of the pores is limited by the heat of the water – industrial dyeing of polyester is carried out at 130°C in pressurised equipment!

Full colour can be achieved when heat transfer printing with disperse dyes as in this image by Linda Chapman.

Using disperse dyes on natural fibres, such as cotton and wool, are not effective but can be combined with reactive dyes to colour blends of polyester/cotton. This technique is used industrially in controlled conditions.

Disperse Dye Bath Technique:

To dye 100gm fabric in 3 litres of water.

Before dyeing, it is important to check whether the fabric is ‘Prepared for Dyeing’ (PFD) or requires scouring to remove any grease, oil or starch. Run a few droplets of cold water onto the fabric. If they soak in quickly, no scour is necessary. To remove starches, size and oils, add 5mls of Synthrapol (a non-ionic detergent) along with 2-3 litres of water for each 100gms of material. Stir gently over a 15 min period, and then rinse thoroughly in warm water. It is possible to use household detergent, but the alkaline residue may affect the final colour or wash fastness.

1. Heat water in a suitable container (do not use iron, copper or aluminium). If using water from a hard water area, add 3gm Calgon to help counter its alkalinity. Water can be tested using indicator paper.
2. Weigh out disperse dye powder (0.4gm for pale colours to 4gm for stronger colours) and sprinkle into a small amount of tepid water to make a solution.
3. Add the dye solution to the dye bath along with 3gm of dispersing agent and stir well with a wooden, stainless steel or plastic spoon.
4. Add the fabric to the dye bath and stir gently whilst raising the temperature slowly to 95-100°C over 15-30 minutes (if dyeing acetate, keep the temperature at 85°C). The longer the fabric remains in the dye bath the stronger the shade.
5. Allow the bath to cool to 50°C and check the colour. Add more dye solution to strengthen it and raise the temperature to 80-85°C for a further 10 minutes.
6. Continue step 5 until the desired colour has been achieved.
7. To complete the process, remove the fabric from the dye bath, rinse in tepid water, spin dry and iron.

Heat Transfer Printing using Disperse Dye and Paints

Disperse dyes can be used to great effect in transfer prints. You can create multiple prints onto synthetic fabrics such as polyester, nylon and mixtures of wool and cotton with more than 60% synthetic fibre content. The disperse dye colours will appear dull, only giving the full colour once they have been activated by heat. Testing the colours in advance will give a good indication of the final result. The image here shows the results of a transfer on cotton fabric and polyester fabric. Sampling will also give you an opportunity to check the iron setting and transfer time.

Sketch your design (in reverse) on a non-absorbent paper. Use either heat transfer paints made from the disperse dyes or ready mixed Fibrecrafts Iron-On Transfer Paints or Deka Iron-On Transfer Paints.

Transfer Paint from Disperse Dye: Thin Consistency

1. Use 10-100gm disperse dye (depending on depth of colour required) and sprinkle into 500ml of tepid water.
2. Stir vigorously and leave to stand for 5 minutes.

Transfer Paint from Disperse Dye: Thick Consistency (for better line definition):

1. Slowly add 50gm Indalca PA3R powder to 500ml of cold water and stir vigorously.
2. Follow instructions for thin consistency and add solution to indalca stock.

Method for printing with Transfer Paints:

1. Brush, print, stencil or spray the design onto smooth, non-absorbent paper and allow to dry.
2. Place the design with the paint side against the fabric, using several layers of newspaper as an underlay and a layer of clean paper on top to avoid ink transfer. Set iron between wool and cotton, (cotton setting for a cotton/synthetic mix) and iron for 1-2 minutes. Keep the iron still, since movement can blur the image.
3. The transfer is complete when the paper begins to yellow. For larger patterns, set one area at a time, with a cooling time between transfers.
4. Transfers can be used more than once, but each subsequent application will give a duller image with some colour change. Colours are intermixable, non-toxic, water based and wash fast, with a soft and flexible handle.

The image to the right was created by Linda Chapman using dried wild flowers as a stencil. She painted a sheet of the paper with transfer paint and allowed it to dry before placing it face down over the plants.  When she ironed the back of the painted paper, the paint transferred onto the polyester fabric leaving the white image where the flowers had acted as a mask.

Safety when using Dyes & Chemicals

It is clear that there are sensible precautions to be taken when handling dyes and chemicals, particularly as powders:

• Avoid inhaling dusts, they can produce an asthma type reaction. People with known respiratory problems should not handle synthetic dyes, and particularly the fibre reactive dyes, in powder form. A dust mask should be worn when working with the powders or exposed to an aerosol from spraying dye solutions made up in water.
• Avoid splashing solutions into the eyes, swallowing the materials or prolonged skin contact. A simple ‘non-contact’ approach (most people use gloves to avoid dyeing themselves) plus normal, good, hygiene is sufficient precautions for the occasional user
• Store in clearly labelled containers well away from children, pets and foodstuffs. Treat dye powders and solutions with the same caution as domestic poisons (eg strong cleaners, bleaches or medicines)
• Dispose of spent solutions containing residues of the dyes responsibly. Dilute and pour onto waste land or into the sewage system. They have no known effect on the environment when used in the quantities recommended in the literature