ANNA UNIVERSITY B.TECH, SIXTH SEMESTER
QUALITY ASSESSMENT OF TEXTILES
Time: 3 hours
Max Marks: 100
Answer all the Questions
PART – A (10 x 2 = 20 marks)
1.What are the various on line qualities measured in the modern draw frame?
2.What is the difference between a normal distribution and a standard normal distribution?
3.How does an AFIS differentiate a nep and a fibre?
4.What do you mean by degree of thickening or circularity?
5.What is the effect of gauge length on rate of loading under CRL and CRE principle of tensile testing?
6.What is the amount of irregularity produced due to random arrangement of fibres in a strand?
7.CV% is a better measure of unevenness the U% Why?
8.What are the three different types of instruments used in FAST system?
9.Why do multi layer fabrics give better thermal insulation than the single layer fabric of same thickness and weight?
10.What do you mean by fabric assistance?
PART – B (5 x 16 = 80 marks)
11.Compare the principles involved in measuring the fibre properties in HVI and AFIS.
12.a)i) What is the importance of testing the weakest place in the yarn?
ii) Describe the principle and working of any one instrument that works on constant tension winding principle.
iii) How does this instrument produce load elongation curve? (3+10+3)
12.b)i) What do you understand by CRL, CRE and CRT tensile testing principles?
ii) Explain the working of a single thread and a lea strength tester.
iii) Compare the strength results obtained by each method. (6+8+2)
13.a)i) What are the different measures of mass variation?
ii) How is yarn mass variation measured in evenness tester based on capacitance and optical principles?
13.b)i) What is work of rupture and work factor?
ii) Compare impact strength of woolen and cotton yarns.
iii) How is the impact strength of yarn measured using a Ballistic strength tester?
14.a)i) How is the hand value of the fabric assessed using Kawabata system of instruments?
ii) Explain the principle and working of tensile and shear testers belonging to this system. (4+12)
14.b)i) Compare tearing strength of twill and plain fabrics having same yarn and fabric specifications.
ii) Explain the determination of tearing strength of a fabric using any one of the instruments. (2+14)
15.a) Write short notes on the following
i)On line testing in Card, Draw frame and Comber
ii)Significance test (8+8)
15.b) Write short notes on the following
ii)Design of Experiments (8+8)