About this previous year paper
Course: B.Tech (Textile Engineering)
Subject Code: EC401
Subject Title: Principle of Fabric Manufacture
Exam Type: Theory
Duration: 3 Hours
Maximum Marks: 100
SECTION – A (10 × 2 = 20 Marks)
Short conceptual questions focusing on key machine functions and definitions
| No. | Question | Explanation |
|---|---|---|
| (a) | Separate Traverse | A yarn guide mechanism that moves independently of the drum to prevent ribbon formation during winding. |
| (b) | Patterning | Formation of repetitive yarn layers or ridges on a package caused by synchronized drum and yarn speeds. |
| (c) | Objective of Sizing Continuous Filament Yarn | To improve strength, reduce hairiness, and increase abrasion resistance for smooth weaving. |
| (d) | Size Add-On | Percentage increase in yarn weight after sizing, calculated as: |
Size Add-On (%)=(W2−W1)W1×100\text{Size Add-On (\%)} = \frac{(W_2 - W_1)}{W_1} \times 100Size Add-On (%)=W1(W2−W1)×100
where W1W_1W1 = dry yarn weight, W2W_2W2 = sized yarn weight. |
| (e) | Function of Balloon Breaker | Controls yarn balloon size and tension during winding to avoid entanglement and improve unwinding efficiency. |
| (f) | Warper Drum vs Warper Beam | The drum stores yarns temporarily for transfer, whereas the beam feeds yarns directly to the loom or sizing machine. |
| (g) | Function of Lease Rods in Sizing | Maintains yarn order and prevents tangling during drying and winding. |
| (h) | Why Sizing Not Done in Weft Yarn? | Weft yarn undergoes lower abrasion and tension during weaving; hence sizing adds unnecessary stiffness. |
| (i) | Function of Jacquard | Controls individual warp threads for complex pattern weaving (floral, brocade, damask). |
| (j) | Secondary Motion in Loom | Includes take-up and let-off motions that regulate fabric winding and warp release during weaving. |
SECTION – B (5 × 10 = 50 Marks)
Descriptive and practical questions emphasizing mechanisms, faults, and industrial practices
(a) Common Winding Faults and Remedies
| Fault | Cause | Remedy |
|---|---|---|
| Ribbon Formation | Improper drum–traverse ratio | Use separate traverse or electronic control |
| Slough-Off | Improper tension or soft edges | Use correct tension, flange ends |
| Hard Edge | Excess tension | Adjust traverse speed |
| Cross Winding | Incorrect package angle | Calibrate machine settings |
(b) Latest Developments in Winding Machines
Automatic Package Doffing
Yarn Clearing Sensors (Optical/Electronic)
Precision Winding (Electronic Traverse)
Anti-Patterning Drives
PLC & Microprocessor-based Tension Controls
(c) Warper Beam Defects, Causes, Remedies
| Defect | Cause | Remedy |
|---|---|---|
| Uneven Yarn Layers | Faulty tension control | Uniform tension monitoring |
| Sloughing | Improper beam speed | Adjust speed ratio |
| Creases | Excess moisture | Optimize drying temperature |
(d) Direct vs Sectional Warping
| Feature | Direct Warping | Sectional Warping |
|---|---|---|
| Output | Single beam | Multiple sections merged |
| Suitable for | Uniform warp | Varied color pattern |
| Efficiency | High | Moderate |
| Example | Grey fabrics | Shirting, suiting |
(e) Drying Methods in Sizing
Hot Air Drying: Uses heated air; moderate speed.
Cylinder Drying: Yarn passes over steam-heated rollers.
Infrared Drying: High-speed drying for synthetic yarns.
Combination Systems: For efficient, energy-saving drying.
(f) Slasher Sizing Machine – Line Diagram
Components: Warp beam → Tension rollers → Size box → Drying cylinders → Lease rods → Winding beam.
Yarn Path: Ensures uniform impregnation, drying, and winding.
(g) Types of Motions in Loom
Primary Motions: Shedding, picking, beating-up.
Secondary Motions: Take-up and let-off.
Auxiliary Motions: Stop motion, warp protector, weft detector.
(h) Common Fabric Faults and Remedies
| Fault | Cause | Remedy |
|---|---|---|
| Missing Ends | Warp breakage | Proper stop motion |
| Double Pick | Shuttle fault | Adjust picking motion |
| Broken Picks | Low weft tension | Tension adjustment |
| Reed Marks | Dirty/damaged reed | Regular maintenance |
SECTION – C (2 × 15 = 30 Marks)
Comprehensive and mechanism-based questions
Q3. Winding Machines (with Diagrams)
Types:
Drum Winder (Precision / Non-Precision)
Cone Winder
Pirn Winder
Automatic Winder (Autoconer)
Advantages: Uniform tension, clean packages, higher productivity.
Disadvantages: Costly, maintenance-heavy, power consumption.
Q4. Shuttleless Looms – Working Mechanism
| Type | Weft Insertion Method | Key Features |
|---|---|---|
| Projectile Loom | Small metal projectile carries weft | High speed, heavy fabrics |
| Rapier Loom | Flexible/telescopic rapier | Suitable for multi-color weft |
| Air-Jet Loom | Compressed air propels weft | Lightweight yarns, very high speed |
| Water-Jet Loom | Water jet insertion | Best for hydrophobic yarns |
| Multiphase Loom | Multiple sheds simultaneously | Very high production efficiency |
Q5. Types of Winding Machines (Repeat/Expanded Form)
Drum-driven vs Spindle-driven Winders.
Includes diagrammatic representation of yarn traverse and package formation.
Discussion of control parameters: yarn tension, traverse ratio, winding angle.
Summary
This Principle of Fabric Manufacture (EC401) paper covers:
| Unit | Key Topics |
|---|---|
| I | Winding principles, faults, and latest automation |
| II | Warping (Direct & Sectional), beam preparation |
| III | Sizing – process, drying, machine layout |
| IV | Loom motions – primary, secondary, auxiliary |
| V | Shuttle & Shuttleless weaving technology |