Determine the correctness or otherwise of the following Assertion [a] and Reason [r] Assertion: In shuttle loom, late shedding is preferred for filament weaving. Reason: In late shedding, the timing of shed dwell matches with the timing of shuttle travel through the shed, and therefore, it minimises the rubbing of warp yarns.
Assertion and Reason Analysis
This question asks to evaluate the truthfulness of two statements regarding shuttle looms used in filament weaving.
Evaluating Assertion [a]
- Assertion [a]: In shuttle loom, late shedding is preferred for filament weaving.
- Filament yarns are sensitive to abrasion. Shuttle looms involve a shuttle moving across the loom width, which can cause friction.
- Late shedding involves opening the warp shed later in the weaving cycle.
- This timing allows the shuttle to pass through the shed with potentially less interference from the warp yarns.
- Conclusion: Assertion [a] is true, as late shedding helps protect delicate filament yarns.
Evaluating Reason [r]
- Reason [r]: In late shedding, the timing of shed dwell matches with the timing of shuttle travel through the shed, and therefore, it minimises the rubbing of warp yarns.
- Shed dwell refers to the duration the shed remains open.
- In late shedding, this dwell period is optimized to coincide with the shuttle's transit across the loom.
- When the shed dwell aligns with shuttle travel, the warp yarns are held apart during the critical moment of weft insertion, reducing friction and rubbing.
- Conclusion: Reason [r] is true and accurately explains the mechanism.
Relationship between Assertion and Reason
The reason correctly explains why late shedding is beneficial for filament weaving in shuttle looms. By synchronizing the shed dwell with shuttle movement, the rubbing of sensitive warp yarns is minimized, directly supporting the assertion.
Final Conclusion
Both the assertion [a] and the reason [r] are true, and the reason [r] provides the correct explanation for the assertion [a].
Important Questions from FABR Loom Mechanisms Shedding
- Group I lists the components of the weaving machine and Group II lists their functions. Match the component with its function.
Group I Group II P Conjugate/matched cams 1 Driving the cloth roller with slip
driveQ Worm and worm wheel 2 Continuous positive take up
motionR Friction clutch device 3 Motion of sley in rapier loom S Lease rod 4 Separation of the warp sheet
forming the shed Amongst the following, the correct condition(s) that will reduce bumping during weaving is/are
- Group I lists weaving machine related parameters and Group II contains the shortcomings of these parameters. Match the machine related parameter with its shortcoming.
Group I Group II P. Variable heald staggering 1. Not favourable for heavy fabric Q. High eccentricity ratio 2. Reduction in shed height R. Fixed heald staggering 3. Reduction of sley dwell S. Late shedding 4. Higher vibration in weaving machine Group I gives a list of loom motions and Group II contains loom systems. Match the motion from Group I with the corresponding system from Group II.
Group I Group II P. Shedding 1. Matched cam Q. Picking 2. Seven wheel R. Beat-up 3. Rapier S. Take-up 4.Jacquard For a shuttle loom, producing plain woven fabric, if each of the dwell periods of the shedding cam corresponds to one-third of crank shaft rotation, the sum of the two dwell periods of the cam (in degree) is_____.
