# FIBRE Sampling

STUDENT OF TEXTILE ENGNEERING (Jawaharlal Nehru Government Engineering College, Sundernagar ) at Home
Aug. 31, 2017                 1 of 17

### FIBRE Sampling

1. Presentation on fibre sampling
2. Q. What is textile testing? • Testing can be defined as the process of determining the properties of different kinds of substances.
3. Q. What is purpose of taking sample? • To draw conclusions about populations from samples, we must use inferential statistics which enables us to determine a population`s characteristics by directly observing only a portion (or sample) of the population.
4. SOME BASIC TERMS :- • Sample: Is relative small fraction which is select to represent a population sampling method. • Test specimen: this is the one that is actually used for the individual measurement and is derived from the laboratory sample. Normally, measurements are made from several test specimens.
5. Type of Sample:- • Numerical sample :- A sample in which proportion of long medium and short fibre would be same in sample as in population. • Random sample :- In this type of sample every individual in the population has an equal chance of being included in it. • Biased sample :- when the selecting sample is influenced by other factor other then chance then sample is not true representative.
6. Sampling method for fibre:- From bulk there are two methods :- 1. Zone technique. 2. Core sampling . From combed / sliver roving :- 1. Numerical sample. 2. Length biased sample . 3. Random draw method.(for sliver) 4. cut square method.(for yarn)
7. Zoning technique :-
8. Zoning techniques :- is popular techniques for testing method of fibre, where the property may vary considerably from place to place. Procedure:- • Collect handful of fibre randomly from at least 40 bales. • Each handful is divided into 2 parts out of which one is discarded and other is retain. • Again divide the retain part into half. • Repeat the process until about 5 grams of fibre remain in handful. • Treat each handful in similarly manner and collet all the fibre from 40 zone to have the final sample of 5 gram.
9. Core sampling :-
10. Core sampling:- Procedure:- • Cutting tip dia. is lesser than coring tube. • helps sliding the core upside the tube penetrates. • helps retaining the core as it is withdrawn. • No. of cores are extracted and combined. • Different sizes of tube 14, 15, and 18mm. • After removal cores are kept in air tight container immediately. • Hydraulic coring machine for large number of samples.
11. Fibre sampling from combed sliver/Roving & yarn :- • Numerical sample :- the removal of one sample does not effect the composition of remaining sample then it can be considered as numerical sample and each segment is representative of hole. • Length-biased :- Prepare a length-biased sample in such way that the bias can be allowed for in any calculation (based on some assumptions). • Remove all fibres which are started left of A (X zone) .The green fibres will be unaffected. • Again remove fibres, the fibre will be unchanged.
12. If the removal of one sample does not affect the composition of the remaining samples, then it can be considered as “ numerical sample” and each segment is representative of the whole.
13. RANDOM DRAW METHOD :- • Take out fibre (2mm at each stage) and discard until a distance equal to that of the longest fibre in the sliver has removed. After that each draw will be of numerical samples.
14. CUT SQUARE METHOD:- • Cut all the projected fibres and discarded. The glass plate is then moved back few mm, exposing more fibres with “natural length” without cut. In each case projected fibre ends must be removed.
15. • Thank you