Dyeing And Bleaching Paper 2 WASSCE (SC), 2016

Question 1

  1. Explain starch resist in fabric production.
  2. List five processes for preparing starch paste for fabric production.
  3. State seven methods of producing starch resist fabric with one colour using stenciling technique.

 


Observation

The question was unpopular among the candidates’ and their performance was below average. Some candidates’ failed in stating the methods of producing starch resist fabric with one colour using stencilling technique. This make them loose substantial marks, they were expected to respond to the question thus:

 

(a) It is a process of resisting fabrics with starch paste in batik production. The starch paste is applied to the fabric to prevent the absorption of dyes, thereby creating patterns/designs at the resisted areas.

 

(b) - Get all materials ready such as cassava flour (starch), pot, water, caustic soda, alum, stove, bowl, etc.

- Boil water, add alum and caustic soda.

- Mix a sizeable quantity of cassava flour (starch) with cold water in a container.

- Pour the cassava solution into the boiling water and stir continually to avoid lumps.

- Cook until elastic texture is achieved.

- Allow the paste to cool.

- Leave the paste to ferment for use.

 

(c) - Get all materials ready such as fabric, starch paste, stencil dye, chemicals,etc

- Rinse the fabric to remove factory starch and dry.

- Prepare the starch paste. - Mount the desized plain fabric firmly on the table/floor.

- Draw the design on a rubber carpet, film, coated cardboard, metal plate, and cut out the design to form a stencil.

- Place the stencil on the fabric already mounted on the table/ floor.

- Apply starch paste through the stencil to the fabric.

- Repeat the process until the fabric is covered.

- Leave the fabric to dry properly under shade.

- Prepare a concentrated dye bath/solution.

- Gently dip the starched surface of the fabric into the dye bath/solution.

- Leave fabric in dye bath/solution for a while.

- Remove fabric from the dye bath/solution and spread for oxidation.

- Remove the starch on the fabric with the use of broom/spatula/hog brush, etc.

- Rinse the fabric very well to remove excess dye and starch.

- Dry the fabric.

- Iron the fabric.

- Package the fabric.