Fiber technology 1 171107 PDF

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Fibre Technology I

6.0 ECTS

Ladok code: AT2FT1 The exam is given to: ExamCode:

Date of Exam: Time:

2017-11-07 09:00-13:00

Means of assistance: Calculators.

Total amount of point on exam: 50p Requirements for grading: ECTS: E: 26-30 p, D: 31-35 p, C: 36-40 p, B: 41-45 p, A: 46-50 p. Additional information:

Att empt any 5 qu es tio n s o u t o f 6 .

Next exam date: Will be announced on Kronox.

The results are for the most part posted within three weeks after the exam, otherwise it’s the following date: Important! Do not forget to write the ExamCode on each paper you hand in. Good Luck!

Examiner: Phone number:

Question#1 a) Write a short comparison between Saw and Roller ginning processes. (4) b) Write the definitions of following: (3) 1. LOI 2. Melt flow index (MFI) 3. Fabric cover

c) Given: A 690 m long viscose yarn with 55 g weight absorbs 30% moisture from open environment. The tensile strength of yarn before and after moisture regain was 70 N and 55 N, respectively. (3) Calculate:

1. Wt. of the water absorbed 2. Linear density of viscose yarn before and after moisture regain in dtex and denier. 3. Tenacity before and after moisture regain

Question#2 a) Write a short description of the effects of following on the properties of melt-spun fiber: (4) a. Mol. Wt. b. MFI c. SSDR d. MDR b) What is a die swell? How it can be eliminated during the production of synthetic fibers? (2) c) How the non-woven web of polypropylene can be produced? (2) d) What is the difference between POY, FOY and BCF? (2) Question#3 a) Write the effects of following parameters on fiber properties produced by electrospinning process? (4) a. Polymer concentration b. Mol. Wt. of polymer c. Gap between taylor cone and collector d. MFI b) Why do we get irregular fiber cross-section during the solution spinning processes? (2)

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c) What are the environmental impacts of solution dry and solution wet spinning processes? (2) d) Give three examples of synthetic fibers produced by gel spinning process. (2) Question#4 a) What two precursors are used to produce the carbon fibers? Write the names of three steps involved to convert these precursors to high-modulus carbon fibers. Which precursor gives better quality carbon fibers? (3) b) How different grades of viscose yarn can be produced in viscose process? Explain the process (3) c) Write the names of spinning processes used for the production of Kevlar and Nomex fibers. (2) d) What different options do we have to produce a bulletproof jacket? Write names of different fibers. (2) Question#5 a) What are the different options to manage the textile waste? What is easy to recycle approach? (3) b) What is the principle of capacitive method? Where do we use it? What are the benefits of this method? (3) c) How vibroscobe method works? (2) d) What are the benefits of HVI instruments? (2) Question#6 a) What is the electro spraying process? How does it occur? (2) b) What are the mechanical and chemical textile recycling approaches? (4) c) What is sustainable development in textile sector? (2) d) Why UHMWPE fibers have superior mechanical properties ? (2)

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