Observation

The question was popular among the candidates, and their overall performance was above average. Although some candidates could not identify the heat sources in dyeing, they wrote down caustic soda and hydrosulphite as part of the heat sources in dyeing. These mistakes made them lose some marks. They were expected to respond to the question in the following manner:

(a)        Meaning of labelling of chemicals in dyeing:
It is a means of writing/attaching/tagging/captioning the name of a specific chemical onto a container/nylon for easy and proper identification.                                      
(b)        (i)        Heat sources in dyeing:
Electric kettle, Boiling ring/Water heater, Open fire (firewood/fire), Stove (electric/kerosene/sawdust), Gas cooker/Gas stove, Coal pot, Sunlight, Electric/Coal/Stove pressing iron.                                                                       
             (ii)      Functions of heat sources in dyeing:

• Electric kettle:

(i)         It is used for boiling water for dewaxing.
(ii)        It is used for boiling water to mix/dissolve chemicals for dyeing.
(iii)        It is used to boil water for preparation of starch paste.        

• Boiling ring/Water heater:

(i)         It is used for boiling water to mix/dissolve chemicals for dyeing.
(ii)        It is used for boiling water for dewaxing.
(iii)       It is used to boil water for preparation of starch paste.

• Open fire (firewood/fire):  

(i)       It is used to melt wax.
(ii)      It is used for boiling water to mix/dissolve chemicals for dyeing.
(iii)     It is used to boil water for preparation of starch paste.
(iv)     It is used for boiling water for dewaxing.

• Stove (electric/kerosene/sawdust):

(i)       It is used to melt wax.
(ii)      It is used for boiling water to mix/dissolve chemicals for dyeing.
(iii)     It is used to boil water for preparation of starch paste.
(iv)     It is used for boiling water for dewaxing.

• Gas cooker/Gas stove:

(i)       It is used to melt wax.
(ii)      It is used for boiling water to mix/dissolve chemicals for dyeing.
(iii)     It is used to boil water for preparation of starch paste.
(iv)     It is used for boiling water for dewaxing.

• Coal Pot:

(i)       It is used to melt wax.
(ii)      It is used for boiling water to mix/dissolve chemicals for dyeing.
(iii)     It is used to boil water for preparation of starch paste.
(iv)     It is used for boiling water for dewaxing.

• Sunlight:

(i)       It has the capacity to melt wax into liquid form when exposed to sun.
(ii)      Exposure of waxed fabric unto sunlight is a method of dewaxing in batiking.

• Electric/Coal/Stove pressing iron:

(i)       It is used to stretch out dyed fabric after drying.
(ii)      It is used to dewax dyed fabric in batiking.

(c) Importance of labelling chemicals in fabric decoration:

• It helps for easy/proper identification of chemicals.
• It prevents the dyer from hazard/danger of chemical misuse.
• It ensures proper placement/arrangement of chemicals.
• It saves time for proper/easy location of chemicals.
• It prevents wastage.
• It gives information about the product.
• It helps to avoid wrong measurement of chemicals.