Observation

Most candidates were unable to exhibit a thorough knowledge of bleaching agents involved in bleaching process. Instead they were mentioning the trade names of the finished products like Jik, Hypo which are not acceptable. What is requested of them to list are: sodium hydrosulphite; caustic soda; chlorine; hydrogen peroxide etc. Some misinterpreted the question by listing materials instead of tools needed for bleaching and were unable to identify two types of bleaching. The candidates’ are yet to understand the content of this topic.  They were expected to respond to the question in the following manner:

(a) (i)  

• Oxygen (oxidative) bleaching; 
• Chlorine (reductive) bleaching;
• Optical bleaching.  

              (ii)   

• Hydrogen peroxide;
• Sodium chlorite;
• Fluorescent whitening;
• Sodium hydrosulphite;
• Caustic soda/Sodium hydroxide;
• Calcium hypochlorite;
• Chlorine;
• Thinner;
• Turpentine;
• Chlorine dioxide;
• Sulfurous acid;
• Sulphur dioxide;
• Sodium sulfoxylate formaldehyde;
• Sodium borohydride;
• Bisulfites;
• Sulfites.
• Sodium hypochlorite;
• Sodium Carbonate.                              

(b) (i)   To create designs/patterns.
(ii)        To whiten fabrics/change/removal of colour.
(iii)       To improve impurities from fabrics.
(iv)       To improve the value of fabrics.
(v)        To give room for creativity.
(vi)       To remove stain from fabrics.

(c)             Plastic bowl, Rubber/Hand gloves, Apron/Overall, Safety/Rain/Industrial boots, Safety glasses/Goggles/Sun shade, Nose mask/guard, Mouth mask/guard, Electric/Coal pressing iron, Spoon, Padded table/Table, Cup, Bucket, Mackintosh, Needle/Pins.