Basic textile science

Yarn

• It is a long continues length of interlocked fibers twisted which is used in weaving, knitting, sewing, crochet, embroidery.. Etc.

Yarn twist

• The amount of twist is the important factor in finished consumer’s goods. It determines the appearance and durability of the fabric.
• Fine yarns needs more twist than the coarse yarn (e.g.).: warp needs more twist than the weft.
• Twist setting finish is given to retain the twist with heat or moisture.
• Amount of twist also depends upon the fabric to be woven.
• Soft surface fabric needs slack twist, they are called soft twist yarns.
• Smooth surface fabric needs more twist which gives strength, smoothness, elasticity, and wrinkle resistance.
• By holding the yarn in a vertical position we can observe the direction of twist.
• There are two types of twist "S" and "Z"

Simple yarn:

• When the staple of filament fibers are twisted together it forms a simple yarn.
• The yarn strength will not be high as it is just twisted with the fibers.

Ply yarn:

• When two or more yarns simple yarns are twisted together they are called ply yarns. They are called as 2 ply, 3 ply and so on..

Cabled yarn:

• When two or more ply yarns are twisted they are called cabled yarn.
• It is considered by twisting the plied yarns around each other in opposite direction. (e.g.) Z/S/Z or S/Z/S.
• Opposite twist direction make the plies to grip each other. These yarns will be hard, rough, strong.

Sewing thread :

• It is specifically designed for efficient smooth stitching that will not break during the life of the sewn product.
• The adequacy of the thread depends upon its composition, construction and finish as well as its proper selection for the fabric and type of seam to be used. (e.g.) sewing thread used for stitching a denim fabric.

Novelty yarn:

• The spinning process can produce different decorative effects by varying the amount of twist or by twisting different diameter of yarn together.
• These yarns gives a texture effect on the fabric surface with different color combinations.
• The fabric with these yarns cannot be durable as fabric made of uniform yarns.

Fabric making introduction:
There are so many different ways in fabric making like…

1. Weaving
2. Knitting
3. Non woven
4. Braiding
5. Knotting
6. Felting
7. Leather
8. Fur

Weaving:

• The vertical yarns are called the warp yarns or ends.
• The horizontal yarns are called weft yarns or picks.
• By interlacing the warp and the weft yarns alternatively the fabric is formed.
• Warp will be more strong than the weft as it is mounted to the loom in high tension.
• Weft can be either strong or weaker according to the end product.

Essential weaving operation:

• In any type of weaving four operations are fundamental they are
• Shedding, Picking, Beating, Taking up and Letting off.
• Shedding: Raising specific warp yarns with the help of the hardness or heddle frame.
• Picking: Inserting filling yarns through the shed.
• Beating: Pushing filling yarns firmly in place with the help of reed.
• Taking up and Letting off  :Winding the finished fabric on the cloth beam and releasing more warp from the warp beam.

There are two types of loom hand loom and power loom:

• Hand loom: Hand loom means a loom powered by hand and it is operated manually production is less.
• Power loom: It is operated with the help of electricity where the production is more.
• Shuttle loom: It contains a shuttle with bobbin of filling yarn. It is the oldest kind of loom. The disadvantage is that the shuttle sometimes causes abrasion on the warp while passing through and causes yarn breaks which stops the machine.
• Shuttle less loom: To overcome the disadvantage of shuttle loom different kinds of shuttle less looms have been developed

Basic weaves

Plain weave:

• It needs two heddles. Each filling yarns goes under and over the warp yarns.
• It is used extensively for cotton fabric and fabrics that has to be decorated with print design.

Basket weave:

• It is the variation of plain weave.
• Two or more filling yarns with a corresponding number of warp yarns.
• they are woven in a pattern of 2x2, 3x3, instead 1x1 which is a plain weave

Twill weave:

• It forms a diagonal line formation on the fabric.
• (e.g.) Denim fabric
• There are two types of twill weave, right hand twill and left hand twill
• There are different variations of twill like wavy twill, herringbone…

Satin weave:

• It is similar to twill but generally uses from 5 to as many as 12 hardness
• The surface where the warp float is more is called Satin.
• The surface where the weft float is more is called Sateen.
• Generally the sateen weave will be seen at the back of the satin fabric.