Question

CDT test gives information about

• A. Birefringence of fibre structure
• B. Crystallinity of fibre structure
• C. Orientation of fibre structure
• D. Specific Gravity of fibre structure

Hint:

• CDT (Critical Dissolution Time) Measures the time taken for a fiber to dissolve in a specific solvent under controlled conditions.
• CDT is sensitive to the fiber's internal structure, including crystallinity, molecular orientation, and morphological features.
• Higher CDT generally indicates a more ordered, stable, and crystalline structure.
• It is often used to assess the effects of processing like heat setting, drawing, and annealing on synthetic fibers, which primarily alter crystallinity and orientation.
• While both crystallinity and orientation affect CDT, it's commonly used as an indicator of changes in the crystalline state.

Answer 1

The Correct Option is B

The CDT test, also known as the crystallite orientation distribution test, provides information about the crystallinity of fibre structure. This test is crucial in the field of textile engineering and fibre science as it helps determine the degree of crystallinity within a fibre, which affects the fibre's physical and mechanical properties.

Options	Explanation
Birefringence of fibre structure	Birefringence measures the refractive index difference due to structural anisotropy, not directly related to crystallinity.
Crystallinity of fibre structure	The correct answer; measures the level to which molecules are arranged in an ordered, crystalline manner, directly impacting properties like strength and thermal stability.
Orientation of fibre structure	Refers to the alignment of molecular chains along the fibre axis, affecting tenacity and elongation but is a separate concept from crystallinity.
Specific Gravity of fibre structure	Refers to the density relative to water; helps in comparing different fibres in terms of weight but is unrelated to crystallinity.