Structural, Physical and Chemical Characterization of Fiber?

Structural, Physical and Chemical Characterization of Fiber?

Answer:
Fibre inspection:

A number of systems are available for characterization of the structural, physical, and chemical properties of fibres.

a) Optical and Electron Microscopy: Optical microscopy (OM) has been used for many years as a reliable system to determine the gross morphology of a fibre in longitudinal as well as cross-sectional views.

b) Elemental and End-Group Analysis: The qualitative and quantitative analysis of the chemical elements and groups in a fibre may aid in identification and characterization of a fibre

c) Infrared Spectroscopy: Infrared spectroscopy is a valuable tool in the determination of functional groups within a fibre.

d) Ultraviolet-Visible Spectroscopy: The ultraviolet-visible spectra of fibres, 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 at various wavelengths by unsaturated groups giving an electronically excited molecule.

e) 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 fibre in solution in a high-intensity magnetic field.

f) X-Ray Diffraction: X-rays diffracted from or reflected off of crystalline or semicrystalline polymeric materials will give patterns related to the crystalline and amorphous areas within a fibre

g) Thermal Analysis: Physical and chemical changes in fibres may be investigated by measuring changes in selected properties as small samples of fibre are heated at a steady rate over a given temperature range in an inert atmosphere such as nitrogen.

h) Molecular Weight Determination: Molecular weight determination systems provide information concerning the average size and distribution of individual polymer molecules making up a fibre

i) Mechanical and Tensile Property Measurements: Mechanical and tensile measurements for fibres include tenacity or tensile strength, elongation at break, recovery from limited elongation, stiffness (relative force required to bend the fibre), and recovery from bending.

j) Specific Gravity: The specific gravity of a fibre is a measure of its density in relation to the density of the same volume of water, and provides a system to relate the mass per unit volume of a given fibre to that of other fibres.

k) Environmental Properties: Environmental properties include those physical properties which relate to the environment in which a fibre is found. Moisture regains, solvent solubility, heat physical phenomenon, the physical impact of warmth, and also the electrical properties rely on the environmental conditions encompassing the fibre.

l) Chemical Properties: The chemical properties of fibres embrace the results of chemical agents as well as acids, bases, oxidizing agents, reducing agents, and biological agents resembling moulds and mildew on the fibre and light- and warmth elicited chemical changes inside the fibre.

End-Use Property Characterization:

End-use property characterization systems 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. End-use systems are usually voluntary or mandatory standards developed by test or trade organizations or by government agencies. Organizations involved in standards development for textile end-use include the following:

• American Association of Textile Chemists and Colorists (AATCC) 
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• American National Standards Institute (ANSI) 
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• American Society for Testing and Materials (ASTM) 
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• Consumer Product Safety Commission (CPSC) 
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• Federal Trade Commission (FTC) 
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• Society of Dyers and Colorists (SDC) 
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• International Standards Organization (ISO) 

End-user properties characterizations are determined on the following aspects:

Characteristics involving Identity, Aesthetics, and Comfort: Fibres are well-known by common, generic, and trade names. The Textile Fibre product identification Act, administered by the Federal Trade Commission, established generic names for all major categories of fibres supported the structure of the fibre.

Characteristics Related to Durability and Wear: The useful life of a fabric depends on a number of factors, including the strength, stretch, recovery, toughness, and abrasion resistance of the fibre and the tearing and bursting resistance of the fabrics made from that fibre

Physical and Chemical Characteristics and Response of Fibre to Its Environmental Surroundings: The physical and chemical characteristics of a fibre affect a number of important end-use properties:

Heat (physical and chemical) effect on fibres, including the safe ironing temperature and flammability,

Wetting of and soil removal from the fibre, including laundering, dry cleaning, and fibre dyeability and fastness, and

Chemical resistance, including resistance to attack by household chemicals and atmospheric gases, particularly in the presence of sunlight.