Question 08 (Textile Engineering & Fibre Science)
During roller drafting, better fibre control is achieved by flexing the fibre strand over the bottom roller. The reason for this is
|(A)||Enhanced fibre to fibre coefficient of friction|
|(B)||Enhanced fibre to fibre friction|
|(C)||Reduced slippage of top roller|
|(D)||Reduced fibre to metal friction|
Frequently Asked Questions | FAQs
How the friction field is generated during drafting in fibres?
During the drafting process in fibers, the friction field is generated by the interaction between the fiber and the drafting rollers. The friction field is the force that opposes the motion of the fiber and determines the level of attenuation or stretching that the fiber undergoes.
The drafting process involves passing the fiber through a set of rollers that rotate at different speeds. The speed difference between the rollers causes the fiber to be attenuated or stretched to the desired thickness and strength. As the fiber passes through the rollers, it rubs against the surface of the rollers, generating a friction force.
The magnitude of the friction force depends on several factors, including the coefficient of friction between the fiber and the roller surface, the fiber diameter, and the speed of the rollers. The coefficient of friction is affected by several factors, such as the surface roughness of the rollers, the fiber type, and the presence of any lubricants or additives.
The friction field is essential in the drafting process as it determines the level of attenuation or stretching that the fiber undergoes. If the friction field is too high, the fiber will be over-drafted, leading to thin, weak yarn. On the other hand, if the friction field is too low, the fiber will be under-drafted, leading to thick, uneven yarn. Therefore, controlling the friction field is crucial in producing high-quality yarn with the desired properties.