Qualitative analysis of textile fibres by microscopic viewing.

1. GREEN UNIVERSITY OF BANGLADESH
Department Of Textile
Lab Report
Course Code : TE 415
Course Title : Textile Testing & Quality Control III Lab
No Of Experiment : 01
Name Of Experiment : Study on qualitative analysis of textile fibres by
microscopic viewing.
Remarks:
Submitted By:
Name : Md Rakibul Hassan
ID : 183014057
Section : E2
Department : Textile
Submitted to:
Name : Avijeet Datta
Designation : Lecturer
Department : Textile

2. Experiment No: 01
Experiment Name: Study on qualitative analysis of textile fibres by microscopic
viewing.
Introduction:
A number of methods are available for characterization of the structural, physical, and chemical
properties of fibers. Various methods are used for fiber identification like microscopic methods,
solubility, heating and burning method, density, and staining etc. End-use property characterization
methods often involve the use of laboratory techniques which are adapted to simulate actual
conditions of average wear on the textile or that can predict performance in end-use.
Fiber Identification Methods
There are different types of textile fibers used in the apparels and also the types and numbering of
yarns.Therefore it is necessary to learn the different methods to identify different textile fibers.
The knowledge of identifying the textile fibers helps a producer of garments to identify the type of
fiber and the care to be taken in maintaining the fabrics made of a particular type of fiber. This is an
important factor for labeling of the garments, which includes specifying the fiber content in the
garment.
There are different tests which could be used for the identification of the textile fibers such as burning
test, microscopic test, solubility test, optical test, density test etc. We would be discussing the basic
tests like burning, feeling, microscopic and chemical tests of identifying the textile fibers.
Nontechnical testing does not require any special equipment or setting for identification of fiber.
The different nontechnical methods of identifying the textile fibers are:
• Feeling Test
• Burning Test
These tests are useful and simple to perform and also provide ready identification under certain
circumstances.
● Microscopic Identification: Positive identification of many natural fibers is possible
using the microscope
● Solubility: The chemical structure of polymers in a fiber determines the fiber’s basic
solubility characteristics
● Heating and Burning Characteristics: The reaction of fibers to heat from an open
flame is a useful guide in the identification of fibers.
● Density or Specific Gravity: Fiber density may be used as an aid in fiber identification
● Staining: Fibers have differing dyeing characteristics and affinities dependent on the
chemical and morphological structure of the fiber.
Structural, Physical and Chemical Characterization:
A number of methods are available for characterization of the structural, physical, and chemical
properties of fibers.
● Optical and Electron Microscopy: Optical microscopy (OM) has been used for many
years as a reliable method to determine the gross morphology of a fiber in longitudinal as well as
cross-sectional views.

3. ● Elemental and End-Group Analysis: The qualitative and quantitative analysis of the
chemical elements and groups in a fiber may aid in identification and characterization of a fiber
● Infrared Spectroscopy: Infrared spectroscopy is a valuable tool in the determination of functional
groups within a fiber
● Ultraviolet-Visible Spectroscopy: The ultraviolet-visible spectra of fibers, dyes, and
finishes can provide clues concerning the structure of these materials, as well as show the nature of
electronic transitions that occur within the material as light is absorbed in
various wavelengths by unsaturated groups giving an electronically excited molecule.
● Nuclear Magnetic Resonance Spectroscopy: Nuclear magnetic resonance (NMR) spectroscopy
measures the relative magnitude and direction (moment) of spin orientation of the nucleus of the
individual atoms within a polymer from a fiber in solution in a high-intensity magnetic field
● X-Ray Diffraction: X-rays diffracted from or reflected off of crystalline or semi crystalline
polymeric materials will give patterns related to the crystalline and amorphous areas within a fiber
● Thermal Analysis: Physical and chemical changes in fibers may be investigated by measuring
changes in selected properties as small samples of fiber are heated at a steady rate over a given
temperature range in an inert atmosphere such as nitrogen.
● Molecular Weight Determination: Molecular weight determination methods provide
information concerning the average size and distribution of individual polymer molecules making up
a fiber
● Mechanical and Tensile Property Measurements: Mechanical and tensile measurements for fibers
include tenacity or tensile strength, elongation at break, recovery from limited elongation, stiffness
(relative force required to bend the fiber), and recovery from bending.
● Specific Gravity: The specific gravity of a fiber is a measure of its density in relation to the density
of the same volume of water, and provides a method to relate the mass per unit volume of a given
fiber to that of other fibers
● Environmental Properties: Environmental properties include those physical properties which relate
to the environment in which a fiber is found. Moisture regain, solvent solubility, heat conductivity,
the physical effect of heat, and the electrical properties depend on the environmental conditions
surrounding the fiber.
● Chemical Properties: The chemical properties of fibers include the effects of chemical agents
including acids, bases, oxidizing agents, reducing agents, and biological agents such as molds and
mildews on the fiber and light- and heat-induced chemical changes within the fiber
Microscopic Appearance of textile fibres
1. Cotton:
Longitudinal View
•
• Mature flat and ribbon-like with convolutions, thick wall and small lumen
• Immature very thin wall and a large lumen with few convolutions
• Dead very thin and almost transparent
• Mercerized smooth and cylindrical, fewer convolutions and lumen or
sometimes may be absent
Cross-Sectional View

4. ○ Kidney Shaped
○ Elliptical
○ Very thin like a strip
○ Nearly round or circular
2. Linen:
Longitudinal View
Smooth and Bamboo like with cross marking nodes, no lengthwise striations, narrow lumen.
Cross-Sectional View
Sharp polygonal shape with straight sides. Immature oval shape with a large
lumen.
3. Hemp
Longitudinal View
Smooth and cylindrical with a cross marking nodes, no lengthwise striations, broad
Lumen
Cross-Sectional View
Partly polygonal
4. Jute
Longitudinal View
Cylindrical with uneven in diameter, a lumen is broad and varies greatly
Cross-Sectional View
Rounded polygonal with a central lumen
5. Ramie
Longitudinal View
Irregular and broad with cross marks irregular distributed, a conclusion may appear
Cross-Sectional View
Oblong
Natural Fibres: Animal Fibres
1. Wool

5. Longitudinal View
Cylindrical, irregular, rough surface, scale-like structure, dark medulla may appear on coarse wool
fibres
Cross-Sectional View
Nearly round or circular, medulla may appear
2. Silk:
Longitudinal View
Smooth surface, Structureless, triangular shaped transparent rod(Wild silk/Tussah silk – broader
fibre with fine, longitudinal lines passing across filament)
Cross-Sectional View
Triangular shape with rounded corners(Tussah silk flat wedge or spindle-shaped.
Man-made Fibres:
1. Viscose Rayon

6. Longitudinal View
○ Normal type fairly dense longitudinal striations or fine lines
○ Special type-may be smooth and Structure less
Cross-Sectional View
○ Irregular with a serrated outline
○ Oval or round
2. Cellulose Acetate fibres
Longitudinal View
Uniform in width with a few distinct longitudinal striations
Cross-Sectional View
Irregular with a serrated outline
4. Acrylic
Longitudinal View
Smooth surface, uniform diameter, rod-like appearance, some types with irregularly spaced
striations

7. Cross-Sectional View
Rounded or Dumbbell shaped
5. Polyester
Longitudinal View
Structureless, uniform diameter, rod-like appearance
Cross-Sectional View
Circular
6. Nylon Longitudinal View
Structureless, uniform diameter, rod-like appearance
Conclusion: From this experiment we learnt about qualitative analysis of textile fibres by
microscopic viewing. It will be helpful in our future life.