Question

Which of the following is correct pertaining to fibre fracture?

• A. change in mass / unit volume
• B. change in fibre length
• C. change in fibre fineness
• D. change in fibre crimp

Hint:

• Fiber fracture means the fiber breaks.
• The most direct result of a fiber breaking is that its length is reduced (it becomes shorter pieces).
• This impacts the overall fiber length distribution in a sample of fibers.
• Properties like material density and fineness are generally unchanged by the fracture event itself.

Answer 1

The Correct Option is B

Fiber fracture is the act of a fiber breaking into two or more pieces. When a fiber fractures:

• (a) change in mass / unit volume (Density): The intrinsic material density does not change due to fracture. The pieces are still made of the same material.
• (b) change in fibre length: This is the defining characteristic of fracture. An originally longer fiber becomes shorter segments. The average fiber length of a population of fibers decreases if fractures occur.
• (c) change in fibre fineness: Fineness (e.g., tex, denier, diameter) is a property of the fiber's cross-section and material. Fracture splits the fiber along its length, not typically altering its cross-sectional dimension significantly (though localized necking might occur before a tensile break). The resulting pieces generally have the same fineness as the original fiber.
• (d) change in fibre crimp: Crimp is the waviness of a fiber. While stresses leading to fracture might temporarily affect crimp (e.g., straighten it), the act of fracture itself doesn't fundamentally alter the fiber material's inherent crimp characteristics. The broken pieces would generally exhibit similar crimp to the original.

The most direct and primary consequence of fiber fracture is a change (specifically, a reduction for individual segments and creation of new ends) in fiber length. \[ \boxed{\text{change in fibre length}} \]