Application of Dyes

APPLICATION OF DYES

 How To Dye Cloth

Aim  : To dye a  cloth

Materials required :- Water, dye, metal container, bucket, salt, white vinegar and heater

Procedures : Pre wash the garment to remove all the impurities from the cloth. Then put the dye in the water stir it till it dissolves then add salt to the solution and place the container on heater When the solution starts boiling put the fabric to be dyed in the solution and stir continuously . After around half an hour remove the cloth and hang it to dry. After drying put it into the bucket  containing water and a little white vinegar. This fixes the dye. This process can be practiced for home dyeing.

Machine dyeing

Although still hand dyeing is very common at homes and different laboratories Large-scale commercial manufacturing is done by various machines. There are n number of machines for dyeing cloth but they are mostly classified into three different types, those in which the material to be dyed is moved through the dye solution, secondly those in which the dye solution is circulated through the material and lastly those in which there is movement of both the material and the dye solution.

There are three basic methods for moving the material through the dye solution. In one of these, hanks of the material to be dyed are fastened to a wheel, which rotates them through the solution. In another method, the material is drawn up and down over a series of rollers immersed in the solution. In a third method, cloth that is wound around one roller is passed into the solution, under a guide roller beneath the surface of the liquid, and then rewound on another roller. There are variations of each of these methods.

There are many methods for circulating the dye solution through the material. In one of these, loose fibers are placed in perforated containers through which the solution can be circulated. In another method, hanks of yarn are fastened to a frame, which is then lowered into a tank through which the solution is circulated by propellers.

Union Dyeing. Union cloth is a type of cloth manufactured from more than one type of fibers, such as cotton and wool or viscose and acetate rayon. The best method to dye such a type of cloth is by dyeing  each kind of fiber separately with the appropriate kind of dye and then to weave the colored yarns into cloth. But this process is expensive. One more process is to convert the  dyed fiber to an undid one and then complete the coloring operation by dyeing the cloth. The cheapest and the most commonly  method  is to make dye from the right mixture of dyes that will color all the components of the fabric and then dye the cloth in this mixture

Stencil Dyeing

Aim :- To study stencil dyeing

Material:-paper stencil, paper clips, dyes, cloth etc.

Procedures: - A stencil is created by cutting a paper in a required pattern to be colored. Pre soak the fabric  in washing soda,  wrung it out. Then lay the fabric flat on the table . Attach the stencil to the fabric with the help of dress making pins or aerosol adhesive. The color is then passed through the cut out areas to dye in the perfect shape of the pattern.

Result :- This is how stencil dyeing is done

Screen Printing:-  it is a type of stencil printing.. Silkscreen printing is also used for dyeing a cloth on a commercial level In this process the design is first traced on a silk screen, and the portions that will appear uncolored are lacquered. Dye paste is then rubbed over the surface of the screen and penetrates the unlacquered silk to give the desired pattern to the cloth beneath the screen. A separate screen is needed for each color.

Spray painting

The stencil is made on a paper and attached to the cloth . Care should be taken that the all the edges of the stencil are properly attached to the cloth otherwise the sprayed color may spread under the edges, thus spoiling the clean outline if the design

Block printing:

This process is commercially used for dyeing the cloth in a certain pattern. This method of printing is practiced in India and china for many centuries. A perfect wooden or a rubber block is made in a desired pattern. The making up of this wooden block requires a very experienced carpenter. In prepared blocks are then dipped in the dye, raised portions of prepared blocks receive dye and then transfer it to the material to be printed. For getting good results skilled workers are required