Abstract

Objective

The goal of this science fair project is to test how strongly fiber-reactive dyes color different fabric types.

Introduction

From the shrouds of mummies in ancient Egypt, to the ball gowns of ladies in the Victorian era, to the tie-dyed shirts of modern hippies, dyed cloth has played an important role in human society. Early dyes were made using natural resources, like plants, berries, minerals, and seeds. Some of the earliest examples of cloth dyed with these natural substances come from ancient Egypt during the time of the New Kingdom during the reigns of pharaohs like Queen Hatshepsut and King Tutankhamen. Archeological finds from China and India also contain early examples of dyed cloth.

During ancient times, the cloths, just like the dyes, were made from a natural resource—natural fibers, like cotton, linen, and wool. Later, as advancements were made in chemistry and manufacturing, humans learned to make other fibers, like polyester, nylon, and rayon, known as synthetic fibers.

In addition to what type of material they are made from, another way to categorize fibers is by their chemistry. Cotton and linen fibers are cellulose-based (as is rayon, a manufactured fiber). Cellulose is the main component of plant cell walls—cotton fabric is made from cotton plants and linen is made from flax plants. Wool and silk are both animal-protein-based natural fibers. Wool is made from the hair of sheep, and silk is made from silkworm cocoons.

Although dyes were originally made from natural sources, today's dyes are often synthesized (made) by chemists. By understanding how the molecules of dye react with the fibers, chemists can design many vibrant and color-fast (meaning the dyed color doesn't fade or run off when washed) dyes.

In this science fair project, you'll study one type of dye, called fiber-reactive dye, by dyeing several different types of fabrics with the same dye. Which fiber types will react most strongly with the fiber-reactive dye? You'll judge the results by comparing the colors of your fabric samples. One quantitative way to categorize colors is by hue, saturation, and brightness. The Bibliography, below, has references to get you started on your research about dye and fabric chemistry, as well as color. So read up, formulate your hypothesis, and start coloring. Who knows, in the end you might be able to put your new-found understanding of fabric dyes to work to create the ultimate tie-dye shirt!

Terms, Concepts, and Questions to Start Background Research

• Natural fiber
• Synthetic fiber
• Cellulose
• Protein
• Molecule
• Fiber-reactive dye
• Quantitative
• Hue
• Saturation
• Brightness
• pH
• Water solubility
• Soda ash

Questions

• What are the different types of fibers and how are they made?
• What types of dyes are used for different textile fibers? Why?
• What is the chemistry behind fiber-reactive dyes?
• How can colors be quantitatively described?
• How do factors like pH and water solubility affect dyeing?

Bibliography

These websites offer insights into the history of dyeing cloth:

• McCloy, H. (2000). A Brief History of Dyestuffs and Dyeing. Retrieved June 14, 2009 from http://kws.atlantia.sca.org/dyeing.html
• Jennings, J. A. (2004). Tie-Dye Through The Ages - a history of tie-dye. Retrieved June 14, 2009 from http://www.tie-dye.us/tie-dye-history.htm

Information about types of fibers and textiles can be found at these websites:

• Armstrong, W.P. (2006). "Plant Fibers: Fibers For Paper, Cordage & Textiles."Wayne's Word: An Online Textbook of Natural History retrieved June 18, 2009 from http://waynesword.palomar.edu/traug99.htm
• AFMA. (2005). Fiber Products. Retrieved June 18, 2009 from http://www.fibersource.com/f-tutor/prods.htm

These references contain information about the chemistry of fiber-reactive dyes:

• Dharma Trading Co. (2009). Dye Chemistry: Quick Explanation Of The Chemical Processes Involved In Tie-Dyeing. Retrieved June 18, 2009, from http://www.dharmatrading.com/info/dye_chemistry.html
• Burch, P. E. (2003). The Chemistry of Dyeing: Reactive Dyes. Retrieved June 18, 2009, from http://www.pburch.net/dyeing/chemistry_reactivedyes_lesson.shtml

Consult these references for information on describing color with HSB:

• Abramson, Ed. (2008). Relationships between HSB and RGB Color Descriptions and the Java Built-in Colors Retrieved July 9, 2009, from http://home.comcast.net/~ed-abramson/14ColorTest/HSB-and-RGB-Colors.html
• Jewett, T. (2002). HSB: Hue, Saturation, and Brightness Retrieved June 18, 2009, from http://www.cecs.csulb.edu/~jewett/colors/hsb.html

Materials and Equipment

Note: The fiber-reactive dye powder, soda ash, and textile detergent listed below are all specialty items. You may be able to purchase them at a local craft store. If not, they are available from online vendors like the Dharma Trading Co. at www.dharmatrading.com.

• Five different types of white fabric samples. Purchase enough to make at least three 20-cm x 20-cm squares of each type. Possible types of fabric include:
  1. Cotton
  2. Linen
  3. Wool
  4. Rayon
  5. Nylon
  6. Polyester
  7. Cotton-polyester blends
• Permanent marker
• Scissors
• Ruler, metric
• Measuring cup, liquid
• Textile detergent, especially formulated for removing non-bound dye particles from freshly dyed fabric. Can be purchased online; Dharma Trading Co. offers the most common brand, Synthrapol, catalog #SYNPT, as well as their own, non-toxic alternative, the Dharma Professional Textile Detergent, catalog #PTD16.
• Spoon
• Measuring spoons, to be used only for dye projects, and not for cooking afterward:
  1. Teaspoon (1)
  2. Tablespoon (1)
• Fiber-reactive dye powder. Note: Your results might be easier to interpret if you use a bold color like red, blue, or green. Pastel colors and yellows might be more difficult to evaluate.
• Salt
• Soda ash
• Plastic container that can comfortably hold 1 quart (qt.) of water. Caution: This container will be used for mixing the soda ash solution and should not be used for food or beverage afterward.
• Clean glass jar, 10 ounces (oz.) or larger (1)
• Sealable plastic bag, 1-gallon size (1)
• Safety goggles
• Rubber gloves
• Optional: Camera

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Experimental Procedure

Important Notes Before You Begin:

1. Do your background research so that you are knowledgeable about the terms, concepts, and questions above. In particular, you should learn about the different fiber types used in fabrics, and about fiber-reactive dye chemistry.
2. Pick several different types of fabric to dye; try at least five. Use your background research to make predictions about how well different fabric types will be dyed with fiber-reactive dyes.

Dyeing the Fabric Samples

1. For each fabric type, cut out three 20-cm x 20-cm squares. Use the permanent marker to label each of the squares with its fabric type.
2. Pre-wash the fabric squares by putting them in a normal clothes washing machine with 1/4 cup of the textile detergent. Wash using hot water, if possible. Allow the fabric squares to air dry.
   1. The pre-washing removes any residual chemicals on the fabrics from the fabric manufacturing process (e.g., sizing, preservatives, or oils) that might interfere with the dye process.
3. Put 2 teaspoons (tsp.) of powdered dye and 1 tablespoon (tbsp.) of salt in the glass jar. Add 1 cup of warm water and mix thoroughly to form a concentrated dye solution.
4. Wet all the fabric squares and place them in the plastic bag. Carefully pour the concentrated dye solution into the bag. Add an additional 1/2 cup of water to the bag and seal it, being careful to trap as little air as possible in the bag.
5. Let the bag and dye sit for 20 minutes. Every couple of minutes, gently squeeze the bag to evenly coat all the pieces of fabric with the dye.
6. While the dye and fabric are soaking, make your soda ash solution. Caution: Soda ash is caustic. Wear eye goggles and gloves when mixing the soda ash solution, and when rinsing the fabric samples after dyeing.
   1. Put 2 tbsp. of soda ash in the plastic container. Add 1 qt. of warm water and mix thoroughly.
7. After the dye and fabric samples have soaked for together for 20 minutes, carefully open the plastic bag and add 1/2 cup of the soda ash solution. Reseal the bag, being careful to trap as little air as possible.
8. Gently squeeze the bag to completely mix the soda ash, dye, and fabric. Let the bag sit for 1 hour, gently squeezing every 10 minutes.
9. After 1 hour, carefully dump the contents of the bag into a sink and rinse the fabric until the water runs clear. Caution: Make sure to wear your eye goggles and gloves during this step.
10. Once the fabric is well-rinsed, do a final wash in the washing machine, using the textile detergent. This step is identical to step 2 and will remove any final dye particles which are not bound to the fabric. Allow the samples to air-dry.

Collecting and Analyzing Your Data

Your goal is to determine the effect of fabric type on the strength of the reaction between the fiber-reactive dye and the cloth (if there is any effect!). Below are two suggestions of how to collect and analyze your data—try both. You might be able to think of additional ways to analyze the data, too.

1. Method 1: Look at all the fabric squares. Try grouping them by color. In a data table, like the one below, in your lab notebook, write down the type of fabric in each grouping, along with a description of the color.
   1. Do all the fabric squares of a particular fabric (for example, all three of the cotton fabric squares) belong in the same color grouping?
   2. Do color groupings contain more than one type of fabric?
   3. Have at least three other volunteers repeat step 1 of this section. Record the data from them, too. And compare it to your own visual groupings.
   4. How do your predictions compare to your results?

Table 1. This sample data table shows how to organize the type of data collected using method 1, above.

2. Method 2: Pick one of the fabric squares. Using the sliders in the color tool in Figure 1 below, adjust the hue, saturation, and brightness until the color on your monitor matches the fabric sample. Record the hue, saturation, and brightness values in a data table, like the one below, in your lab notebook. Repeat this step for all of the fabric squares.
   1. Calculate the average hue, saturation, and brightness values for each type of fabric. Graph the averages on a bar chart, where the x-axis is fabric type and the y-axis is the average value. You should have one graph for each type of value: hue, saturation, and brightness. You can use paper, or a website like Create a Graph to create your graph.
   2. Which fabric type has the highest average hue? How about saturation or brightness? What about the lowest average value for each of these? Would you describe each of those as the most or least strongly dyed fabric type?
   3. How do your predictions compare to your results?

3. Note: You might want to take pictures of the fabric squares for your science fair project display board.

Variations

• Before synthetic dyes were created, humans used natural dyes. Do some background research and pick one or more natural dyes to try in the above science fair project. Caution: Natural doesn't necessarily mean non-toxic. Be careful to pick safe dyes, like turmeric or berries.
• Some methods suggest pre-soaking the fabric in a soda ash solution, and then adding dye (the reverse of the Experimental Procedure, above). Does the order of these steps make a difference in the color of the dyed fabric? Design an experiment to find out.
• You've seen how blue jeans fade gradually over time. There are many different experiments related to fading that you could try. For example:
  1. Do all fabrics fade equally with washing? Set aside one sample of each fabric type from your dyeing experiment. Then wash the other samples multiple times, comparing with the original sample after each washing. You can even take this further—does the wash temperature make a difference? Does dye color make a difference?
  2. Do all fabrics fade equally with exposure to sunlight? Set aside one sample of each fabric type from your dyeing experiment. Then expose the other samples to sunlight for different lengths of time. Keep track in your lab notebook. Compare the sun-exposed samples to each other and to the original, unexposed, samples.

• For more science project ideas in this area of science, see Chemistry Project Ideas.

Credits

Sandra Slutz, PhD, Science Buddies

This science fair project is based on these sources:

• Schisler, L.J. (2003). Which Fabric Type Bonds Best With Fiber Reactive Dyes? California State Science Fair Abstract.
• Craft, H. (n.d.). Dyeing Fabric. Retrieved June 18, 2009, from http://www.thecraftstudio.com/heddi/dying.htm

Last edit date: 2010-01-29 15:00:00