Basic Viva For Textile Engineers (Dyeing Related) Part-3

 

61. Which group present in azoic dye?

Ans: Azo group.

62. With which azoic components rate of exhaustion decrease?

Ans: Temperature.

63. Why azoic dye is called developed dye?

Ans: Due to formation of dye in fibre during dyeing process.

64. How many stages in azoic dyeing process?

Ans: 3. a) Naptholation, b) Diazotization, c) Coupling.

65. How insoluble napthol converted into soluble in water?

Ans: By treating with alkali.

66. How many types of napthol according to substantivity?

Ans: 1. Low substantively, 2. Medium substantively, 3.

Higher substantively

67. What is textile printing?

Ans: Textile printing is the process of applying colour to

fabric in definite patterns or designs. In properly printed

fabrics the colour is bonded with the fiber, so as to resist

washing and friction.

68. What area the printing ingredients?

Ans:

Dyes/pigment,

Wetting agent,

Thickener,

Solvents/dispersing agent,

Defoaming agent,

Oxidizing and reducing agent,

Catalyst and oxygen carrier,

Acids and alkalis,

Carrier and swelling agent,

Miscellaneous agents.

69. Why normal thickeners are not suitable for printing with reactive dyes?

Ans: They contain terminal –OH group which readily reacts

with reactive dye.

70. What is finishing?

Ans: Before marketing, all the process which are applied on

fabric is called finishing.

71. Give the classification of finishing?

Ans: 1. Physical (Temporary, Permanent), 2. Chemical

(Temporary, Permanent).

72. What is mercerization?

Ans: It is physio chemical process when cotton /yarn is

treated with 15-25% (55-65%º Tw) caustic soda solution at

a temperature of 20-30º C

73. Why mercerization is used?

Ans: To increase the luster of fabric.

74. How rain water collected for dyeing?

Ans: Rain collected immediately after precitation, which is

the purest of all natural waters.

75. For which material permanent hardness in water occurred?

Ans: Chlorides or Sulphates of Calcium and Magnesium.

76. Which oils are used in soap manufacturing?

Ans: Cotton seed oil, Coconut oil, Oliver oil, Soya bin oil,

Palm oils, Ground nut oil.

77. What is acid soap?

Ans: Soap and free fatty acid molecules can become

associated to form acid soap.

78. What is chromogen?

Ans: The dye structure which contain both chromophore

and auxochrome is called chromogen.

79. What is the mean of H.E.C?

Ans: Hydroxy Ethyl Cellulose.

80. How many types of dyeing machine is use?

Ans: 1. Fibre dyeing machine, 2. Yarn dyeing machine, 3.

Fabric dyeing machine.

81. What is shear stress?

Ans: Shear stress is the resistance of the liquid to flow

under the influence of an applied force

82. Why steaming is required?

Ans: Steaming is required after dyeing reactive dye fixation.

83. What is the reactive group of reactive dye?

Ans: Vinyl sulhone group & halogen group.

84. Why sodium chloride is used in dyeing process?

Ans: Sodium chloride is used as a electrolyte for penetration

of dye from dye bath to fabric.

85. Why wetting agent is used in dyeing process?

Ans: To remove surface tension.

86. Why sequestering agent is used?

Ans: To remove hardness of water.

87. What is problem produce for hardness?

Ans: Soap waste, scale form.

88. What is problem of scale?

Ans: Heal loss is produce.so cost is increase.

89. What is printing?

Ans: Printing is a localized dyeing.

90. Where binder is used?

Ans: In pigment printing.