Warp Breakage Factors in Weaving
The probability of warp breakage during the weaving process is influenced by several factors related to the warp yarn's properties and the weaving conditions.
Impact of Warp Extensibility
Warp extensibility refers to the yarn's ability to stretch under tension. When warp extensibility is decreased, the yarn has less capacity to absorb the dynamic stresses applied during weaving, particularly at the moment of shedding and picking.
- Low extensibility means the yarn reaches its breaking point more quickly when subjected to tension.
- Therefore, a decrease in warp extensibility directly increases the likelihood of warp yarns breaking.
Analysis of Other Factors
Let's examine why the other options are less likely to increase warp breakage:
- Warp unevenness is decreased: A more uniform warp (less unevenness) generally leads to smoother running and potentially less breakage.
- End density is decreased: While end density affects fabric structure and tension distribution, a decrease does not inherently cause more breakage per yarn.
- Warp hairiness is decreased: Reduced hairiness results in a smoother yarn surface, which minimizes friction and snagging, thereby typically reducing the chance of breakage.
Based on this analysis, the most direct cause for an increased probability of warp breakage among the choices is the reduction in warp extensibility.
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 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.
