FAULT OF SPAUN YARN & TYPES OF SIZING

Fabric

PRESENTATION DAY/12/2012

PREPARED BY Amirul Eahsan

ID: 112-015-041SECTION:A1

PRESENTATION ON FAULT OF SPAUN YARN & TYPES OF

SIZING

PRIMEASIA UNIVERSITY

A lightweight line made of several rope yarns loosely wound together, used for sizings onboard ship. Cord made by twisting together from two to four untwisted yarns of tarred hemp.Spun yarns require that size contribute to yarn strength and that the protruding fiber ends be glued down to make it less hairy. To do this, the sizing solution must have a high viscosity to prevent penetration into the yarn. Optimum protection is afforded when most of the size remains on the yarn surface to coat the yarn and glue down the protruding hair

Spun Yarns

1. Weak2. Hairy3. Over Twisted Yarn 4. Thick place5. Low elasticity6. Slub7. Thin place8. Neps 9. Moree 10. Bakar

FAULTS OF SPAUN YARN

Fig. Different Faults in spaun yarn

A yarn that is found to be either below standard breaking specifications or to be weak enough to cause an abnormally high degree of stops in textile processing. It breaks down so easily as it can not absorb much stretch.

1. WEAK

Fig. Weak Yarn

This is the measure for the protruding fibers from the yarn body. Yarn hairiness denotes the amount of hairs (fibres) protruding above the surface of the textile yarn. Especially, in case of staple spun yarns, since multiple fibres are bound in a single yarn, fibres will tend to protrude outside the body of the yarn even though proper twisting is done for that yarn.

2. Hairiness

Fig. Hairiness

3. Over Twisted Yarn

Presence of excessive twist in yarn segments. Mainly caused by the wrong selection of twist wheel resulting stifness.

This types of yarns are heavy in weight as it contains so many thick portions in its length. It causes poor knitting performance.

4.THICK PLACE

Fig. Thick place

This type of yarn can not retain its original shape or size perfectly after withdrawing the effective load or pressure from it .

5. Low Elasticity

Fig. Low Elasticty

Abnormally thick place of length 1-4 cm and about 5-8 times larger than average yarn diameter showing less twist at that place of the yarn. Causes more end breaks in the ensuring process, Shade variation in dyed fabric.

6. SLUB

Fig. Slubs

Thin places causes more end breakage in yarn.

7. THIN PLACE

Fig. Thin Place

A small knot of entangled and unorganized fibers cause formation of short, thick places in yarns and therefore less uniform fabric appearance.

8. Neps

Fig. Neps

9. Moree

Moree means the improperly joined broken ends. Which hampers the production.

10. Bakar

Trash (mainly seed coats) present in the yarn structure. Decreases the quality of yarn.

Sizing is the process of applying protective adhesive coating on the yarn surface. This is the most important segment of weaving preparatory process. Because sizing has direct influence on the weaving efficiency. Better the quality of sizing higher the weaving efficiency & vice versa. In fact without sizing, in most of the cases it is almost impossible to run the weaving process.

Sizing

The qualities required for a good size depends, in the main, on what type of yarn is in the warp. For example, fine count spun yarns require more protection than do plied yarns or course count spun yarns.

Quality Sizing

Fig.Sizing Machine

Size Cooking ↓ 

Creeling ↓ 

Yarn Feeding ↓ 

Sizing (in show box) ↓ 

Drying↓ 

Leasing ↓ 

Denting ↓ 

Empty Beam Feeding & M/C Running ↓ 

Ends Cutting ↓ 

Doffing

Flow Chart For Sizing:

Sizing gives a protective coating on yarn surface to tolerate the friction on loom machine. The size yarn may reduce the yarn breakage & yarn rupture during weaving process. As a result, fabric quality becomes better & production becomes higher.

Sizing is Called the Heart of Weaving

1. Pure sizing

2. Light sizing

3. Medium sizing

4. Heavy sizing

DIFFERENT TYPES OF SIZING

When sizing is done in yarn which produces unbleached fabric is called pure sizing.

7-10 % size ingredients are used on the weight of yarn.

1. Pure sizing

This is used for dyeing and printing. 11-15% sizing ingredients are used on

the weight of the yarn.

2. Light sizing

For increasing strength & weight of the yarn medium sizing is used.

16-40% sizing ingredients are used on the weight of yarn.

3. Medium sizing

To increase weight of the yarn its application on twisted yarn and lower count of yarn.

Above 40% sizing ingredients are used on the weight of yarn.

4. Heavy sizing

After all the discussion above, we can say that, Sizing is truly the heart of weaving. It improves the quality of productions and ensures the protections of warp.

THANK U ALL…