THEORY EXAMINATION (SEM–IV) 2016-17 Principle of Fabric Manufacture

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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