This document discusses a study investigating the relationship between various knitting parameters and spirality in single jersey knitted fabrics. It measured wales per inch, courses per inch, stitch length, yarn count, and spirality in 9 fabric samples. The results showed that spirality decreases with higher WPI and CPI, and increases with longer stitch length and finer yarn count. The study aimed to help minimize fabric waste by better understanding how to control spirality.

2. Submitted To
Md. Habibur Rahman
Assistant Professor
Dept. of Textile Engineering
BUBT
Submitted by
Md. Ali Zinna M.AArif Ali
ID: 11123107015 ID:11123107020
Intake: 6th Intake: 6th
Dept. of Textile Engineering Dept. of Textile Engineering
BUBT BUBT

3. Abstract
The parameters like WPI, CPI, Stitch Length, Yarn Count
are very important for making single jersey knitted fabrics.
In this presentation, it is mainly focused on spirality. It is a
serious problem of knit fabrics. This project work investigates
the different studies on wales per inch, course per inch, stitch
length, yarn count and spirality, and their relations. The study
also concludes that stitch length is directly proportional to fabric
spirality. The WPI and CPI is inversely proportional to the spirality.
The yarn count relation with spirality is finer the yarn spirality increases.
The fabric spirality is minimized up to 50% after the finishing process
as compared to its gray stage spirality.

4.  The demand of Knitted apparels are increasing day by day in global
market in comparison to woven apparels. Around 50% of the clothing
needs are met by knitted goods.
 It is well known that knitted fabrics has some distortional tendency of
bending over the loops. The term called spirality. Spirality of knitted fabric
occurs when wale is not in right angle or 90° with the course, forming an angle
of spirality.
 It provides some serious problems for garment making.
 The project proposed to measure spirality of plain single jersey fabric
manually with protractor at finished stage. It also contain the effect of WPI,
CPI, Stitch Length and count on spirality.
Introduction

5. Objective:
1. To understand the effect of different parameters on spirality.
2. Determination the effect of different parameters on spirality.
3. To related the relation among studied parameters.
4. To know the effect of spirality on weft knitted fabric,
5. To know the causes of spirality and their effect.

6. Spirality
A distortion of loops of circular knitted fabric in which the wales
follow a spiral path around the axis of the fabric tube.
Figure: Spirality

7. Causes of spirality
There are different types of causes for occurring fabric spirlity.
The following are some predominant causes
of spirality in knitted fabrics.
1. Yarn twist multiplier.
2. Spirality occurs in knitted fabric because of asymmetric loops.
3. Number of feeders.
4. Different spinning technologies such as ring, rotor, air jet etc.
5. Variation in knitting tension.
6. Washing wet treatments.
7. Direction of machine rotation has little influence on spirality.

8. Methodology
We collected 9 samples of single jersey weft knitted fabric.
In the study we calculate…
 Average WPI.
 Average CPI.
 Average Stitch Length
 Average Spirality.
 Average Yarn count.
To find out the average effect of WPI, CPI, Yarn Count, and Stitch Length
on Spirality.

9. Calculation of average WPI
 Count the wales widthwise in 10 inches of fabric.
 Divide the result by 10 to get the WPI.
 5 readings are taken and average the value to get the average WPI for every
sample.
Calculation of average CPI
 Count the number of course lengthwise in 10 inch of fabric.
 Divide the result by 10 to get the CPI.
 5 readings are taken and average the value to get the average CPI for every
sample
Methodology

10. Calculation of average angle of spirality
 We use “ISO 16322-2, Textiles — Determination of spirality after
laundering.” method for the measurement of spirality.”
 The washing method is “ISO 6330:2012, Textiles -- Domestic washing
and drying procedures for textile testing.”
 Mark a wales vertically then measure the angle of spirality between
course and marked wales by means of protractor.
 5 readings are taken for every sample and average the result for every
sample.
Methodology

11. Calculation of average Stitch Length (SL)
 Count 100 wales and marked very well.
 Open and stretch the 100 wales and measure the length in centimeter.
 Divide the length by 100 to get stitch length in millimeter.
 5 readings are taken for all samples and average to get average Stitch
Length for all samples.
Calculation of average yarn count
 20 yarns of length12 inches and weight it by means of electrical balance.
 20 yarns of 12 inches is in total 240 inches or 6.67 yards of yarn.
 Weight of all sample are recorded.
 We did the operation for 5 times for all samples and put the values in
following equation.
N=(L× w)/(l× W)
Methodology

12. Overview of average WPI, CPI, Yarn Count, Stitch Length and Spirality
Sample
no.
Wales per inch
(WPI)
Course per inch
(CPI)
Stitch length (SL) Count Angel of
Spirality
1 32 40 2.75 36 9.5°
2 42 60 2.24 30 5°
3 40 51 2.38 32 5.2°
4 38 48 2.30 23 5°
5 35 44 2.59 23 8°
6 37 45 2.50 28 7.5°
7 38 48 2.40 25 6°
8 30 36 2.82 36 11.5°
9 36 42 2.60 34 8°

13. Result and discussion
Result of effect of WPI on spirality
Sample
no.
Wales per
inch (WPI)
Angel of
Spirality
1 32 9.5°
2 42 5°
3 40 5.2°
4 38 5°
5 35 8°
6 37 7.5°
7 38 6°
8 30 11.5°
9 36 8°

14. Result of effect of CPI on spirality
Result and discussion
Sample no. Course per
inch (CPI)
Angel of
Spirality
1 40 9.5°
2 60 5°
3 51 5.2°
4 48 5°
5 44 8°
6 45 7.5°
7 48 6°
8 36 11.5°
9 42 8°

15. Result of effect of Stitch Length on spirality
Sample no. Stitch length
(SL)
Angel of
Spirality
1 2.75 9.5°
2 2.24 5°
3 2.38 5.2°
4 2.30 5°
5 2.59 8°
6 2.50 7.5°
7 2.40 6°
8 2.82 11.5°
9 2.60 8°
Result and discussion

16. Result and discussion
Result of effect of yarn count on spirality
Sample no. Yarn Count Angel of
Spirality
1 36 9.5°
2 30 5°
3 32 5.2°
4 23 5°
5 23 8°
6 28 7.5°
7 25 6°
8 36 11.5°
9 34 8°

17. Final overview in graphical representation
Result and discussion
0
10
20
30
40
50
60
70
1 2 3 4 5 6 7 8 9
Effect of WPI, CPI, Stitch Length. Yarn Count on
spirality
Wales per inch (WPI)
Course per inch (CPI)
Stitch length (SL)
Count
Angel of Spirality

18. Conclusion
To know about the effect of WPI, CPI, Stitch Length,
and Count on spirality is very important to make knit
fabrics with better physical properties. Spirality could
be a fault of knit fabrics. So, it make much wastage in
fabrics. Where 80% garment cost depend on fabric
costs. In cutting section it can make huge wastage of
fabrics if it is not removed. To gather knowledge
about the spirality is very important to minimize the
wastage. So, the effects of such parameters like WPI,
CPI, Stitch Length, and Count on spirality is very
important.
Though we feel the work somewhat unfinished due to
lack of necessary arrangements for more work, but
still the progress we’ve made on this matter should be
taken into consideration.

19. Limitations
 If we could work with more sample our result
would be more accurate.
 We did some experiment manually, if we could
do those experiments by the help of automatic
machine, it would be fine.
 If we could work in a lab it would be more
helpful.