Question 31 (Textile Engineering & Fibre Science)
Consider the following elements in Group I and Group II and choose the correct alternative from amongst A, B, C, and D.
| Group I | Group II | ||
| P | Licker-in | 1 | High speed, fine wires |
| Q | Cylinder | 2 | Fibre rupture, coarse wires |
| R | Flats | 3 | Wires with acute front angle, condensing of fibre |
| S | Doffer | 4 | Slow speed, stripping action |
| 5 | Nep removal, slowest speed |
| (A) | P-5, Q-3, R-2, S-1 |
| (B) | P-1, Q-2, R-5, S-4 |
| (C) | P-4, Q-4, R-3, S-5 |
| (D) | P-2, Q-1, R-5, S-3 |
[Show Answer]
Option D is correct
Frequently Asked Questions | FAQs
What is the function of doffer in carding?
In the carding process of textile manufacturing, the doffer is an essential component of the carding machine. Its primary function is to remove the carded fibers or sliver from the main cylinder, allowing for continuous operation and the formation of a uniform and even sliver. Here are the key functions of the doffer in carding:
Fiber transfer: The doffer transfers the fibers from the main cylinder or the worker and stripper rollers onto itself. As the main cylinder rotates, the fibers are collected and held by the clothing (wire) on the cylinder. The doffer, which also has wire clothing, comes into contact with the main cylinder, enabling the transfer of fibers from the cylinder to the doffer.
Fiber removal: Once the fibers are transferred onto the doffer, it swiftly removes them from the main cylinder’s wire clothing. This action ensures that the fibers are detached from the cylinder, preventing them from being carried around the machine continuously. The doffer’s rotational speed and the design of its wire clothing facilitate efficient and effective fiber removal.
Sliver formation: As the doffer removes the fibers, it forms a continuous strand of fibers known as a sliver. The doffer collects the fibers in a controlled manner and arranges them in a parallel and uniform manner. This helps in aligning the fibers and creating a consistent sliver that can be further processed in subsequent stages of textile production.
Timing synchronization: The doffer plays a critical role in maintaining the synchronization and timing of the carding machine. It ensures that the fibers are removed from the main cylinder at the right moment to maintain a consistent flow of material. Proper timing prevents clogging, fiber breakage, and other issues that may affect the carding process.
Waste removal: In addition to transferring and removing fibers, the doffer also aids in removing waste materials from the carding machine. It helps in dislodging and clearing off shorter fibers, debris, dust, and impurities that may have accumulated on the main cylinder during the carding process. This waste removal contributes to the production of cleaner fibers and improves the efficiency of the carding machine.
In summary, the doffer in carding machines performs crucial functions, including fiber transfer from the main cylinder, efficient fiber removal, sliver formation, timing synchronization, and waste removal. Its role is instrumental in ensuring the continuous operation of the carding process and the production of uniform and quality sliver for subsequent stages of textile manufacturing.
What are main parts of carding machine?
The carding machine is a critical component of the textile manufacturing process, used to produce a continuous strand of fibers or sliver that can be further processed into yarn or fabric. The machine comprises several parts that work together to align, clean, and separate the fibers. Here are the main parts of a carding machine:
Feed rollers: These are the first set of rollers in the carding machine that feed the fibers to the machine. The feed rollers may include an opener, which helps to loosen and separate the fibers before they enter the carding machine.
Taker-in roller: The taker-in roller is the first set of carding rollers in the machine that removes the fibers from the feed rollers and starts the carding process. The taker-in roller has teeth or pins on its surface that grip and pull the fibers through the machine.
Main cylinder: The main cylinder is the central component of the carding machine. It consists of a large cylinder covered with wire clothing or card clothing. The main cylinder rotates and combs the fibers, separating them from each other and aligning them in a parallel orientation.
Doffer: The doffer is a cylinder covered with wire clothing that removes the fibers from the main cylinder, creating a continuous strand of fibers known as a sliver. The doffer rotates at a slightly slower speed than the main cylinder and removes the fibers using a combination of pressure and wire clothing design.
Stripping roller: The stripping roller is a set of rollers that help to remove any remaining fibers from the wire clothing on the main cylinder. The stripping roller has wire clothing with teeth that mesh with the wire clothing on the main cylinder and pull the fibers off.
Condenser: The condenser is a set of rollers that compresses the fibers from the doffer into a uniform sliver. The condenser also helps to remove any remaining impurities or waste materials from the sliver.
Coiler: The coiler is a mechanism that collects and packages the sliver into a cylindrical shape. The coiler rotates and guides the sliver onto a package, such as a cone or tube, creating a consistent and even package of fibers.
Other components of a carding machine may include various sensors, controls, and automation systems that monitor and adjust the process to ensure consistent and efficient operation.
In summary, the main parts of a carding machine include feed rollers, taker-in roller, main cylinder, doffer, stripping roller, condenser, and coiler. These components work together to produce a uniform and consistent sliver of fibers that can be further processed into yarn or fabric.