Anna University New Spinning Technologies Question Paper
NEW SPINNING TECHNOLOGIES
Answer ALL Questions
PART – A (10 x 2 = 20 marks)
1.What is the principle of condensed yarn spinning? Name two commercial models of condensed yarn spinning?
2.What is COM4 value of a condensed yarn? How is it calculated?
3.Why rotor-spun yarns are evener than equivalent ring-spun yarns?
4.How the proportion of wrapper fibres in a rotor-spun yarn is related with fibre length and rotor diameter? What is the acceptable proportion of wrapper fibres in rotor yarns?
5.Give the production speeds of DREF-2000 friction spinner and Murata Vortex Spinner MVS 851.
6.List two appropriate reasons for lower strength of open-end friction-spun yarns as compared to open-end rotor-spun yarns.
7.Name the principle of working of air-jet spinning? Why air-jet spun yarns are known as fascinated yarns?
8.Write the fibre properties in order of importance for air-jet spinning.
9.Mention two end uses of siro-spun yarns.
10.Give the value for proportion of wrapper and production speed in wrap spinning.
PART – B (5 x 16 = 80 marks)
11.i) With an appropriate sketch bring out the details of condensed yarn manufacture on Rieter’s K44 Comforspinner.
ii)Discuss with reasons with important quality characteristics of condensed yarn vis-a-via its equivalent ring-spun yarn.
12.a)i) With a neat sketch describe the principle and method of yarn formation in rotor spinning.
ii) What are the functions of Torque-stop and Draw-off nozzle in rotor spinning?Discuss the effect of Draw-off nozzle profile on rotor-spun yarn character.
12.b)i) Critically comment on the influence of rotor design variables, like rotor diameter, rotor grove geometry and rotor speed on spinning performance and yarn quality.
ii) Calculate the production in kg/hr of a rotor spinner using the data given below: Yarn count: 30 tex; Rotor speed: 90000 rpm; Yarn twist: 1000 tpm; Efficiency: 0.95; No. of rotors per frame: 288
13.a)i) With a neat sketch describe the method of production of yarn on DREF-3 friction spinner. Why DREF-3 yarns are relatively stronger than DREF-2 yarns?
ii) Distinguish between the structures of DREF-2 and DREF-3 yarns.
13.b)i) Mention five important process parameters in friction spinning. Highlight the influence of any two of them on yarn quality.
ii) Write the history of developments in friction spinning and mention four specific applications of friction-spun yarns.
14.a)i) Explain the principle of working of a commercial air-jet spinning machine.
ii) Why Murata Jet Spun yarns are stronger than Toray Jet Spun yarns?
iii) Sketch the different classes of structure in a fascinated yarn with relevant particulars
14.b)i) Compare with reasons any four important characteristics of air-jet spun yarns with equivalent ring spun yarns.
ii) Discuss the production of PLY fil yarns using air-jet principle. How PLY fil yarns differ from air-jet spun yarns.
15.a)i) List the modifications required on an existing ringframe to produce a double-rove spun yarn and highlight the process details with an appropriate diagram.
ii) Name three important process parameters in Siro spinning. Bring out the effect of strand spacing on properties of Siro-spun yarns.
15.b)i) Describe the principle of operation and production of wrap-spun yarns.
ii) Discuss the properties and end uses of wrap-spun yarns.