2. SUPERVISING TEACHER
A.K.M FARIDUL AZAD
Assistant Professor
Head Of The Department
Department of Fabric Manufacturing Technology
Pabna Textile Engineering College,
Shalgaria, Pabna-6600
Name Exam Roll Reg. No. Session
MD.EKRAMUL HASAN 070065 4534 2006-2007
PREPARED BY

3. Abstract
• Spirality is a common problem in weft knitted fabric. It is the de-
twisting tendency of yarn in the fabric. It appears in mostly in
single jersey fabrics but in double jersey fabrics this level in
about zero. The causes of formation of spirality in twistness in
the yarn and increase it by using more number of needles and
multifeeders machine so on. It can reduce in different ways but
not remove from the fabrics.
• Shrinkage is the dimensional change in length and width wise in
the fabric. It mainly occurs for swelling of yarn. So, it appears
more in cotton fabrics than synthetic fabrics. It can reduce the
shrinkage by using stenter machine after dyeing and drying the
fabric. Also, if the higher GSM/lower stitches length/lower twist
fabric contains lower shrinkage of fabric.
• For measuring the spirality and shrinkage at first we have done
ISO-6330 washing then use ISO: 16322-2 for spirality and ISO-
5077 for shrinkage. And these are international standard of
these measuring systems.

4. Shrinkage: A dimensional change resulting in a decrease in the length or width
of specimen subjected to specified condition is known shrinkage.
Spirality: If the Wales of the knitted fabric are not perpendicular to the course
and skew to the right or left Spirality occurs in the fabric. This creates serious
problem, especially in the apparel industry.
Yarn twist: Twist is the measures of the spiral turns given to a yarn in order to
hold the constituent fibers or threads together. Amount twist i. e. TPI greatly
influenced the fabric Spirality.
Twist liveliness: The tendency of a yarn is to twist or untwist spontaneously.
The direction of twist liveliness or torque S or Z twist change that takes place
spontaneously when an end or hanging loop is allowed to rotate freely. Higher
amount of twist leads high liveliness and creates fabric Spirality.
Dry Relaxed State: The fabric moves to this state with time. The dry relaxed is
restricted by fabric structure and fiber type. Only wool can attain this state.
Wet Relaxed State: Static soak in water and dry flat. This state tight structure
doesn’t always reach a true relaxed state. Only wool and silk can attain this
state. Soak water with agitation or agitation in steam or static soak at selected
temperature (below 900
C)

5. Calculation for spirality percentage:
X =Average
deflection length from
the seam line
Y= Sample length,
Spirality% =
Washing process:
ISO 6330
Determination of spirality after laundering knitted fabrics:
ISO 16322-2

6. Causes
The residual torque.
Count of yarn,
 Fabric structure,
GSM
Fabric Relaxation,
No. of feeder.
Twist direction,
Machine rotation,
Spinning system,
Fabric finishing.
etc.

7. Considering the following parameters can
control spirality
Count
The yarn is finer, the spirality will be more due to more twisting.
Fig: Effect of spirality on GSM (34Ne
Combed yarn)
Fig: Effect of spirality on GSM (26Ne
Carded yarn)

8. Twist
Twist multiplier:
TM=TPI/√count
So when TM is increased, TPI also increased & the spirality of fabric also increased.
TM Twist liveness (cm) Spirality (degree)
3.2 19.69 4.2
3.5 25.99 6.5
3.8 28.96 7.3
Twist factor:
TF= TPcm × √tex
So, when TF is increased, TPcm also increased & spirality of fabric also increased.

9. Blending of fibre
• 100% cotton yarn shows more spirality than polyester-
cotton blend yarn on different procedure of dry.
FOR 100% COTTON OF SINGLE JERSEY
FOR BLENDED (COTTON + POLYESTER) OF SINGLE JERSEY

10. Fabric structure
• In single jersey fabric has more spirality than rib & interlock.
• No appreciable problem of spirality in rib & interlock fabric.
Effect of fabric structure with Tumble dry on spirality

11. GSM
• In plain single jersey fabric GSM increases, spirality
decreases.

12. Direction of m/c rotation
• Z-twist yarn gives z skew, s-twist gives s-skew
to the fabric. With multifeed m/cs , the fabric
is created in helix, which gives rise to course
inclination & consequently wale spirality .
Direction depends on the rotational direction
of the knitting m/c. Earlier research work
revealed that, for a clockwise rotating m/c,
the wale would be inclined towards the left.
Thus producing the spirality.

13. Effect of stenter m/c
Before stenter (For Plain Single Jersey Fabric):
After stenter (For Plain Single Jersey Fabric):
If the fabric is delivered to the dryer without sending through the
stenter m/c and completed garments that show lower spirality,
higher shrinkage. On the contrary, it shows tolerate
limit according to buyer requirements by going through the stenter m/c.

14. Types:
• Relaxation shrinkage,
• Felting shrinkage,
• Compressive shrinkage,
• Residual shrinkage.
Causes:
• Shrinkage is mainly due to yarn swelling and the
resulting crimp increase during washing in case of
cotton fabrics. Yarn swelling percentage is more
in polyester cotton blending yarn.

15.  Influencing factors:
• Twist factor: twist factor increases so that shrinkage will be
increases.
• Stitch length: stitch length increases so that shrinkage will be
increases.
• GSM: GSM increases so that shrinkage will be decreases.
• Elasticity of yarn.
 Calculation for shrinkage percentage:
• Shrinkage percentage = (L0-L1) ×100/L0
• Where, L0 = the distance between the datum line before washing
and
• L1 = the distance between datum lines after washing.
 Washing process:
• ISO 6330
 Determination of dimensional change in washing and drying:
International Standard ISO 5077

16. Effect of GSM on Shrinkage (Tumble Dry)
•
In plain single jersey fabric lengthwise and
widthwise decreases with increase in GSM.
Fig: Effect of GSM on Shrinkage in lengthwise
(Tumble Dry)
Fig: Effect of GSM on Shrinkage in widthwise (Tumble
Dry)

17. • In plain single jersey fabric has higher
shrinkage than rib and interlock.
Effect of Fabric Structure on Shrinkage(Tumble Dry)
Fig: Effect of GSM on Shrinkage of different
types of fabrics in length wise (Tumble Dry)
Fig: Effect of GSM on Shrinkage of different
types of fabrics in widthwise (Tumble Dry)

18. • In Terry Fleece Fabric spirality and shrinkage are increases then Fleece
Fabric.
EFFECT OF SINGLE JERSEY DERIVATIVES ON SPIRALITY & SHRINKAGE
(FLEECE & TERRY FLEECE)

19. Result and discussion
• From our project work we can conclude that, in case of
higher count, combed yarn, lower GSM, 100% cotton yarn
used, single jersey structure cause the higher spirality in
the weft knitted fabrics. Also, if anti-clockwise machine
direction and Z twisted yarn causes lower spirality. By using
plating yarn we get lower spirality. Form our experiment
we can also see that among the three drying processes the
result of tumble dry shows greater spirality and flat dry is
lower.
• In case of shrinkage higher the GSM, higher the stitch
length it cause higher shrinkage. In case of fleece, two
thread fleece contains more shrinkage than three thread
fleece. Also we observe from our experiment, the polyester
fabric contains lower shrinkage than 100% cotton fabric.
• Though our project is vast, but we don’t get among time to
arrange the experiment data exactly. It needs more time
data to describe these topics.

20. Remedies For Spirality
 Z & S twist yarn package used in alternate feeder:
If Z and S twist yarn packages are used in alternate feeder
then legs than 1% spirality is found and this is the greatest
way to reduce spirality;.
 Resin treatment:
Cross linking the fabric by means of inter fibre bonding also
reduces spirality. Resin is the form of aqueous solution is
applied and set by passing the fabric through a high
temperature stenter this method is not recommend fro
cotton fabrics, since it weakens the cotton yarn.
 Heat setting:
Steam or hot water setting reduces twist liveliness and
hence spirality. Mercerization is recommended for cotton
yarn, sot that fibers are made to relax permanently.

21. Remedies For Spirality
 Compacting:
If the length of the fabric based on its elongation during processing which,
in turn, reduces the width. It helps in controlling the shrinkage of the
fabric. There are two types of compactors, open and tubular. In tubular
compacting the squeezing line gets on the sides in this process and is
done on natural movement thus controlling spirality. If the wales are
straightened manually then it results in spirality.
 Yarn twist direction and machine rotation direction:
If the machine rotates clockwise then the spirality can be reduced by
suing yarn of S-twist. Otherwise if the machine rotates anti-clockwise the
spirality can be reduced by using the yarn of Z-twist.
 Use of special type of yarn:
One comparative way minimize the spirality is to use the vortex spun yarn
which is obtained from Murata vortex spinning system. And modified
friction spun DREF III yarn reduces yarn snarling and fabric spirality.
 By using plating yarn:
In fabric production when used plating yarn it reduce the spirality.

22. Remedies for Shrinkage
• In order to maintain the weight at a lower shrinkage, a
finer yarn is used.
• In order to maintain the width, a larger diameter
knitting machine or a longer stitch length is necessary.
• In order to maintain the same knitted tightness factor,
or cover factor (square root of tex divided by stitch
length) with a finer yarn, a shorter average stitch
length must be knitted.
• Changes in yarn count and stitch length also change
the stitch density which again changes the weight and
the width for a given level of shrinkage. Changes in the
tightness factor will change the extensibility of the
fabric and will also affect the amount of spirality
(fabric twisting) which may be developed.

23. The end ……thank
you………….1