Observation

Despite the question was unpopular among the candidates, there was an improvement in their performance this year. Their overall performance was above average. Although, some candidates’ misinterpreted the question by writing on techniques of bleaching instead types of bleaching. They are yet to fully understand the content of this topic.  They were expected to respond to the question in the following manner:

(a)Definition of bleaching:

Bleaching is a process of whitening/removing the original/natural colour of textile/fibres/yarns and fabric to form/create patterns/designs by the treatment/application of chemicals/bleaching agents.

(b)  (i)Types of bleaching:

• Oxidative (oxygen) bleaching
• Reductive/Chemical(e.g. chlorine, caustic soda, etc.) bleaching
• Optical/Sunlight/Fluorescen/Photo bleaching   
        

(ii)  Materials for bleaching:

Fabric/Cloth, Water, Bleach/Bleaching agents/Chemicals (e.g chlorine, caustic soda, hydrosulphite, etc.), Rag, Foam, Strings (e.g. twine, raffia, rope); Nylon; Masking tape; Paper stencil; Soap/Detergent .

(c)Stages of patterning a fabric using the splashing technique of bleaching                                                                                                                       

• Get all the materials and tools ready such as fabric, water, rubber gloves, chemicals, etc.
• Desize the fabric.
• Spread fabric on a surface covered with mackintosh or nylon sheet and peg.
• Splash the chemicals/bleaching agents on the surface of the fabric using any suitable tools.
• Allow chemicals/bleaching agent to run on the fabric for a short time.
• Remove fabric and rinse properly with water to stop further chemical reaction.
• Wash with soap/detergent and rinse properly.
• Starched the fabric.
• Dry the fabric.
• Iron the fabric.
• Package the fabric.