Abstract

The aim of my experiment is to determine which of the material used (cherry, tomato & beet) would make the best red color on fabric. It also attempts to find out would fabric type, afterbath, washing and sun have an effect on the color.

The procedures for my experiment began by collecting the required plant materials. Then dye had to be prepared from them. After this four sets of three types of fabric was to be dyed with it. After allowing them to dry, they were to be tested for the effect of fabric type, afterbath, washing and sun on their color

Theory

A DYE can generally be described as a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution and may require a mordant to improve the fastness of the dye on the fiber. A mordant is an element which aids the chemical reaction that takes place between the dye and the fiber so that the dye is absorbed. Mordants (e.g. metallic salts) act on the dye molecules by breaking apart existing links and forming new ones that will bind with the fabric. Not all dyes need mordants to help them adhere to fabric. If they need no mordants, such as lichens and walnut hulls, they are called substantive dyes. If they do need a mordant, they are called adjective dyes.

Common mordants are:

alum, usually used with cream of tartar, which helps evenness and brightens slightly;
iron (or copperas) which saddens or darken colors, bringing out green shades;
tin, usually used with cream of tartar, which blooms or brightens colors, especially reds, oranges and yellows;
blue vitriol which saddens colors and brings out greens;
Tannic acid used for tans and browns.

Based on the source of the dye, it can be broadly classified into two:

Synthetic dyes

Natural dyes

Historically, natural dyes were used to color clothing or other textiles, and by the mid-1800’s chemists began producing synthetic substitutes for them. Nowadays, most of the colors used in commercial textile dyeing are synthetic. But the focus here is on the importance of natural dyes.Natural dyes are a class of colorants extracted from vegetative matter and animal residues.

Natural dyes obtained from minerals

Ocher is a dye obtained from an impure earthy ore of iron or ferruginous clay, usually red (hematite) or yellow (limonite). In addition to being the principal ore of iron, hematite is a constituent of a number of abrasives and pigments.

Natural dyes obtained from animals

A good example is cochineal, which is a brilliant red dye produced from insects living on cactus plants. Purple was extracted from a small gastropod mollusk found in all seas or from a crustacean called a Trumpet Shell or Purple Fish. Estimates are that it took 8,500 shellfish to produce one gram of the dye, hence the fact this dye was worth more than its weight in gold. So only the royal family could afford it.

Natural dyes from plants

Nature has gifted us more than 500 dye-yielding plant species. Earliest evidence for the use of natural dyes from plants dates back to more than 5000 years, with Madder (Rubia cordifolia) dyed cloth found in the Indus river valley at Mohenjo-Daro. There is a whole variety of plants which can be used to make plant dyes. Different parts of the plants can be a source for different type of dyes in case of different types of dyes and plants

Procedure

1) Choose cherries, beets, and tomatoes with the darkest red color and make dyes from each of them.

To make the dye solution:

Chop plant material into small pieces and place in a pot. Add double the amount of water to plant material. Bring to a boil, and then simmer for about an hour. Strain. Now you can add your fabric to be dyed. For a stronger shade, allow material to soak in the dye overnight.

Getting the fabric ready for the dye bath:

You will have to soak the fabric in a color fixative before the dye process. This will make the color set in the fabric.

2) Choose three types of fabric (cotton, wool, polyester) and make four sets of fabric, each set with one piece of each type of fabric. One set is the control.

3) Dye one set of fabric with each of the three dye baths. Put the control in distilled water only. Observe color and intensity.

4) Soak each set (including control) in a vinegar afterbath. Observe color and intensity.

5) Wash each set (including control). Observe color and intensity.

6) Dry each piece of fabric in the sun. Observe color and intensity.

7) Compile the data and then draw conclusions.

Results

The cherry dye solution was close to red in color, but the fabrics were dyed pink.

The beet dye was very dark red, but the dyed fabric turned magenta.

The tomatoes made a light gold dye and dyed the fabric a gold color.

Out of the three fabrics, the wool picked up the color the best, then the cotton.

The polyester had only very pale coloring, with the most color on the polyester dyed with beets.

The afterbath affected the color a lot. It took the color out of the fabric instead of helping the color attach.

Washing and sun had little or no effect on color or intensity

Discussion

Research has shown that synthetic dyes are suspected to release harmful chemicals that are allergic, carcinogenic and detrimental to human health. Ironically, Germany, that discovered azo dyes, became the first country to ban certain azo dyes in 1996.

Lately there has been increasing interest in natural dyes, as the public becomes aware of ecological and environmental problems related to the use of synthetic dyes. Use of natural dyes cuts down significantly on the amount of toxic effluent resulting from the synthetic dye process.

Natural dyes are environment friendly; for example, turmeric, the brightest of naturally occurring yellow dyes is a powerful antiseptic and revitalizes the skin, while indigo yields a cooling sensation. Organic dyeing not only helps preserve the traditional art of weaving and design, but also provides employment and yields economic and ecological benefits.

Commercialization of natural dyes can be successful in the state with systematic and scientific approach for identification of resources, extraction, purification, chemical structure elucidation and promotion of use of natural dyes, thereby enhancing the economy of the local people. Recent work, to discover whether it is possible to use plants as commercially viable sources of dyes has highlighted a significant resource, which would benefit both industrial production and consumer choice