# GATE (TF) Textile 2014 Question Paper Solution | GATE/2014/TF/16

###### Question 16 (Textile Engineering & Fibre Science)

If the diameter of a torsion rod used in projectile loom is doubled then the torque required to twist it would increase by

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Given in the question

Let, initial diameter of torsion rod=d1

Then , final diameter of torsional rod(d2)=2d1

Let, initial torque=

Then, final torque=

The torque required to twist it would increased by=?

Formula:

Where , d is diameter

So,

The torque required to twist it would increase by 16 times. (Answer)

### What is a projectile loom?

A projectile loom is a type of textile weaving loom that uses a shuttle-like component known as a “projectile” to insert the weft yarn across the warp threads to create woven fabric. The projectile is a small, bullet-shaped object that carries the weft yarn across the width of the loom, and it is propelled through the shed of the loom by various means, such as mechanical, pneumatic, or electromagnetic methods.

The principle of operation of a projectile loom can be summarized in the following steps:

Shedding: The shed is created by raising or lowering the warp threads using shedding devices, such as a dobby or a Jacquard mechanism, which determines the pattern of the fabric to be woven.
Picking: The projectile, which carries the weft yarn, is inserted into the shed by means of a mechanical, pneumatic, or electromagnetic propulsion system. The projectile traverses across the width of the loom, passing through the shed, and deposits the weft yarn as it moves.
Beat-up: After the weft yarn is inserted, the reed, which is a comb-like structure, is used to push the newly inserted weft yarn against the previously inserted weft yarn to form a tightly packed fabric structure.
Take-up: The woven fabric is wound onto the cloth roll or take-up roll, which is driven by the loom’s take-up mechanism, and the woven fabric is advanced in the loom for the next cycle of weaving.
Shedding Reset: The shedding devices are reset to create the next shed for the next pick of weft yarn, and the process repeats to create the desired fabric pattern.

Projectile looms are known for their high weaving speed, efficiency, and ability to weave a wide range of fabric types, including cotton, polyester, rayon, silk, and their blends. They are capable of weaving complex patterns, intricate designs, and specialty fabrics, making them suitable for various textile applications, including apparel fabrics, home textiles, technical textiles, and industrial fabrics. However, projectile looms are less commonly used compared to other types of looms, such as air jet looms and rapier looms, due to their higher initial cost and maintenance requirements.