Comparison of Fabric Properties Constructed on Shuttle Loom and Converted Loom (Rapier)

Introduction:

1. Weaving is the process of forming the fabric by interlacing two or more sets of yarns by using a machine called loom.
2. In 1733, john kay invented the fly shuttle which enabled weft to be inserted more rapidly.
3. Steam power was available by 1765. soon power looms were driven by steam and most of the wooden parts were replaced with iron.
4. JAMES NORTHROP, AN ENGLISH MAN INVENTED AN AUTOMATIC WEFT TRANSFER SYSTEM WHICH REPLACED THE WEFT PIRN IN THE SHUTTLE WITHOUT SLOWING OR STOPPING THE LOOM IN 1889.
5. RUTI, A MAJOR LOOM MAKER OF SWITZERLAND MANUFACTURED AUTOMATIC BOBBIN CHANGING NORTHROP LOOM IN 1898.

Limitations:
The power required for picking is proportional to the cube of the loom speed.

For example, if the loom speed is increased from 200 to 300 picks per minute, the power requirement would increase by a factor of (3/2)3 i.e. 3.4 times approximately.

Disadvantages:

1. Greater strain will be imposed on the picking mechanism, thus rendering it liable to frequent failure.
2. Greater amount of noise and vibration.
3. Because of superior energy in shuttle, greater strain is again imposed on the checking mechanism.
4. The movement of shuttle will be more difficult to control and there will be a greater possibility of its ejection from the loom hence resulting in injury of labour or destruction of some loom part.

THE VARIOUS SHUTTLE LESS LOOMS THAT HAVE BEEN DEVELOPED OVER A PERIOD OF ABOUT 50 YEARS CAN BE CLASSIFIED INTO FOLLOWING GROUPS.

1. PROJECTILE LOOMS
2. RAPIER LOOMS
3. FLUID JET LOOMS(AIR JET, WATER JET)
4. MULTIPHASE LOOMS

Advantages: The shuttle less weaving is becoming more and more popular due to the following advantages compared to conventional looms: 

1. Low labour need and high machine productivity due to high speed and wider width of looms. 
2. Reduced labour cost due to higher allocation of looms and productivity. 
3. Defect free cloth for longer length. 
4. Better environment due to low noise level. 
5. Pirn winding process is eliminated 
6. Less value loss of fabrics. 
7. Low consumption of stores and spares. 
8. Less space requirement per metre of cloth.
9. More colours in weft direction (upto 12) by pick and pick method. 
10. Wider width fabrics and multi width fabrics can be woven, 
11. High degree of flexibility to suit a wide range of fibres and counts. 
12. Easily adaptable for market trends. 
13. Bigger flanges can accommodate 3 times more yarn. 
14. Due to less beam changes lower down-time and lesser wastages. 
15. Less dependency on labour skill. 
16. Higher design capabilities dut to microprocessor and electronic controls. 
17. Easy maintenance and less work load for jobbers. 
18. Lesser accidents.

DEVELOPMENT OF MAURATA AIR JET SPINNING: IT HAS SOME TYPE: 

1. MJS (MAURATA JET SPINNING) 
2. MVS(MAURATA VORTEX SPINNING) 
3. MTS(MAURATA TWIN SPINNER)

MAURATA JET SPINNING: 

1. MJS yarn is different in structure as compared to ring spun yarn. mjs yarn is made by wrapping fibers around core fiber.
2. 90% of fibers are placed in the core and remaining 10% are wrapped.
3. The maurata system has two opposing air jets. the second jet has higher twist torque than the first air jet. the fibers are twisted by the air jet nozzles. the fibers are then threaded through twin twist assembly. the fibers on the edge of the sliver are twisted by the first air jet nozzle (weak one). the fibers in the core of the core of the yarn are twist by the second air jet nozzle. the fibers on the edges are wrapped around the core fibers in opposite direction.
4. Air jet spinning is used mainly for spinning from short staple fibers especially cotton and polyester blends

MJS VS RING SPUN: Both are structurally different 

• MJS yarn is different in structure as compared to ring spun yarn. mjs yarn is made by wrapping fibers around core fiber. 90% of fibers are placed in the core and remaining 10% are wrapped. 

• Ring spinning is a method of spinning fibers, such as cotton, flax or wool, to make a yarn. yarn made by continuously twisting and thinning a rope of cotton fibers. the twisting makes the short hairs of cotton stand out, resulting in a stronger yarn with a significantly softer hand.

MJS VS ROTOR SPUN YARN:

• MJS YARN IS DIFFERENT IN STRUCTURE AS COMPARED TO RING SPUN YARN. MJS YARN IS MADE BY WRAPPING FIBERS AROUND CORE FIBER. 90% OF FIBERS ARE PLACED IN THE CORE AND REMAINING 10% ARE WRAPPED. 

• FIBERS BUNDLES FROM FEED STOCK ARE SEPARATED IN THE INDIVIDUAL FIBERS WITH AN OPENING ROLLER IN AN AIR STREAM AND THE SEPARATED FIBERS ARE THEN RECOLLECTED IN ROTOR GROOVE.

ADVANTAGES & DISADVANTAGES OF MJS:

• GOOD EVENNESS (LIKE RING-SPUN YARN)
• GOOD ABRASION RESISTANCE
• LOW PILLING TENDENCY
• LOW SNARLING TENDENCY
• SHRINKAGE ALMOST EQUAL TO RING SPUN YARN
• MINIMUM HAIRINESS
• SOME DISADVANTAGES ARE:
• HIGHER RESISTANCE TO BENDING
• SLIGHTLY LOWER COVERING POWER
• WEAK YARN

Advances: Majority of the developments are taking place on the shuttleless looms in the following directions : 

• to increase productivity of the loom.
• to make the looms more flexible for different kinds of fabric.
• to reduce the down time for changing style, etc.
• application of electronic control mechanisms to increase automation
• development of accessories such as dobby, jacquards, etc.

Parameters Affecting the Properties of Fabric Fabric construction: 
The construction of fabric can be changed by changing the parameters which resultantly affects the properties of fabric like comfort, physical and other properties (fabric properties)

• crimp
• yarn count
• thread density
• effect of weave

Loom Settings: Certain parameters of loom settings i.e warp tension, filling tension, shed geometry, shed height and warp stop motion effect the fabric construction. physical and fabric properties changes with changing the construction of fabric.

• yarn tension
• shed geometry:
• shed height

Effect of Fabric Structure on Properties:

1. GSM
2. PILLING
3. TENSILE STRENGTH
4. TEAR RESISTANCE
5. ELONGATION

Comfort Properties: 

• Air Permeability
• Moisture Vapour Transfer
• Stiffness

Rapier Machines Rapier weaving machines: are the most flexible machines in the market; their application covers a wide variety of fabric styles. the loom speed is about 600-700 strokes/min is the result of the state of the art construction technique, characterized by use of gear sets without plays and by minimum vibration of the reed, the sley and the healed frames.

Mechanism: The weft, which is under constant proper control, remains connected to the cloth as a consequence of the previous insertion (or it remains blocked under the temple in the other cases).

The weft exchange between the two rapiers in the middle of the shed can take place in two different ways, that is:

• negative system
• positive system

Features of Rapier Loom (TECHNICAL SPECIFICATIONS) 

Fabric Width	60" , 68", 72", 76", (Other Sizes Made-to-Order)
Width Reduction	Min 4" & Max. 20" Standard
Performance	Upto 230 RPM or 380 m/min weft Insertion rate
Yarns	Filament, Spun, Mono, Silk, Flat, Jari, Viscose, Bemberg, Slub, Catonic, Roto, PP, Nylon, Acrylic, Glass Fiber, Industrial Yarns
Weft Selector	upto 6 colours (Electronic or Mechanical)
Weft Yarns	Spun: Ne 8 to Ne80, Filament: 20 dtex to 900 dtex
Weft Density	10 to 180 picks/inch , 4 to 70 picks/cm
Weft Insertion	Flexible Rapier Tape with Velvet Sliding Rapier Heads
Weft Feeders	Electronically Controlled
Weft Cutter	Mechanical CAM Drive
Weft Stop Motion	Piezo-Electric with Instant Stop
Shedding	Tappet / Plain, Cammotion Top-Mounted 16 Jack Mechanical Dobby, 600/1200 Hooks Mechanical Jacquard
Warp Beam	Single Warp Beam with 600mm diameter (Powerloom Type)
Warp Let –Off	Mechanically Synchronised with Takeup with Overtension Switch (Optical)
Main Drive	High-Toruqe Break Motor, With Single Pick Forward & Reverse
Cloth Take-Up	7-Wheel & 5-Roll with 3-Emery Rolls Mechanical Takeup with easy doffing arrangement. (400mm diameter)
Sley Drive	Positive Crank Drive (Korean Type)
Selvedge Cutt er	Mechanically Driven
Lubrication	Forced Centralised Lubrication
Control System	Foraward, Reverse Pick, Start & Stop Button, LED Lamp Signal, Production Meter, USB Port (optional)

SPECIAL FEATURES:

• SLIDING HEAD GRIPPER
• SOLID CRANKSHAFT
• CLUTCHLESS MOTOR WITH EBS (ELECTRONIC BREAK SYSTEM)
• WEFT CUTTER CAM DRIVE
• 7-WHEEL TAKE-UP SYSTEM
• 3-EMERY CLOTH ROLL SYSTEM
• INDIVIDUAL LENO BOBBIN SYSTEM
• PRE-ASSEMBLED DELIVERY