ABSTRACT
Blended yarns spun from different blend ratio (70/30, 50/50, 30/70, 10/90)
Flax/Cotton and 100% Cotton were converted into fabrics through the integration of
warp and weft yarns. The blend yarns were used as weft in the fabric construction
using plain weave pattern. The properties of the produced blended fabrics were
studied. The results show useful indications of the differences that exist in their
physical and mechanical properties such as the fabric tensile strength, tearing
strength, abrasion resistance, crease recovery, extension at break, elongation at break,
fabric drape, fabric thickness, fabric crimp and fabric sett. From the study it was
discovered that as the flax content in the blend is increased, both tensile, tearing,
abrasion resistance, fabric thickness and fabric crimp reduces. It was apparent from
the study that in order to produce material of good quality that may be used as
apparel, the flax content in the blend would have to be reduced. The strength of the
flax fibre was greatly affected during the cottonization process,due to the harsh
treatment of the fibres during the cottonization
TABLE OF CONTENTS
Title page- – – – – – – – – – -i
Declaration- – – – – – – – – – ii
Certification- – – – – – – – – – iii
Dedication- – – – – – – – – – iv
Acknowledgement- – – – – – – – – v
Abstract- – – – – – – – – – vii
Table of Content- – – – – – – – – viii
List of Tables- – – – – – – – – xii
List of figures- – – – – – – – – xiii
List of plates- – – – – – – – – – xiv
CHAPTER ONE
INTRODUCTION- – – – – – – – – 1
1.1 Flax- – – – – – – – – – 1
1.2 Cotton- – – – – – – – – 4
1.3 Blending- – – – – – – – – 4
1.4 Fibre distribution in blended yarn structure- – – – – 5
1.5 Statement of research problem- – – – – – 7
1.6 Objective of the research- – – – – – – 8
1.7 Scope of the work- – – – – – – – 8
CHAPTER TWO
2.0 Review Of Literature- – – – – – – – 9
2.1 Effect of spinning parameters on the fabrics – – – – 9
2.2 Mechanical Behaviour- – – – – – – 13
2.2.1 Fabric Sett- – – – – – – – – 14
2.3.2 Fabric Crimp – – – – – – – – 15
2.2.3 Fabric Thickness- – – – – – – – 17
2.2.4 Drape- – – – – – – – – – 18
2.2.5 Crease recovery- – – – – – – – 20
2.2.6 Abrasion resistance- – – – – – – – 21
2.2.7 Fabric tearing strength- – – – – – – 23
2.2.8 Tensile properties of fabrics- – – – – – – 24
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CHAPTER THREE
3.0 Materials and Methods- – – – – – – – 27
3.1 Materials- – – – – – – – – 27
3.2 Equipment- – – – – – – – – 27
3.3 Fabric Production- – – – – – – – 28
3.3.1 Pirn winding operations- – – – – – – 28
3.3.2 Weaving operations- – – – – – – – 28
3.3.3 Fabric conditioning- – – – – – – – 29
3.4 Fabric testing- – – – – – – – – 29
3.4.1 Yarn crimp measurement- – – – – – – 29
3.4.2 Determination of fabric sett- – – – – – – 32
3.4.3 Determination of fabric thickness- – – – – – 34
3.4.4 Determination of fabric drape- – – – – – 36
3.4.5 Determination of fabric crease recovery- – – – – 38
3.4.6 Determination of fabric abrasion resistance- – – – – 40
3.4.7 Fabric tearing strength- – – – – – – 42
3.4.8 Fabric tensile strength- – – – – – – 44
CHAPTER FOUR
4.0 Results and Discussions- – – – – – – – 46
4.1 Fabric Production- – – – – – – – 46
4.1.1 Pirn Winding Operations- – – – – – – 46
4.1.2 Weaving Operations- – – – – – – – 46
4.1.3 Fabric Conditioning- – – – – – – – 47
4.2 Fabric Testing- – – – – – – – 47
4.2.1 Fabric Yarn Crimp- – – – – – – – 47
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4.2.2 Fabric Sett- – – – – – – – – 51
4.2.3 Fabric Thickness- – – – – – – – 54
4.2.4 Fabric Drape- – – – – – – – – 56
4.2.5 Fabric Crease Recovery- – – – – – – 58
4.2.6 Fabric Abrasion Resistance- – – – – – – 61
4.2.7 Fabric Tearing Strength- – – – – – – 64
4.2.8 Fabric Tensile Strength- – – – – – – 66
4.2.9 Fabric Extension and Elongation at break- – – – –
CHAPTER FIVE
5.0 Conclusion and Recommendations- – – – – – 72
5.1 Conclusion- – – – – – – – – 72
5.2 Recommendations- – – – – – – – 74
References- – – – – – – – – – 75
Appendix- – – – – – – – – – 79
CHAPTER ONE
1.0 Introduction
The properties of woven fabrics depend on the type and composition of fibres used.
Thus, flax and cotton fibres are blended in order to achieve properties unachievable
with single fibre type (Lawal, 2008).
1.1 Flax
Flax is a bast vegetable fibre that comes from the stem of an annual plant called
“Linum ussitatissimum”. The plant usually grows within the range of 40-90cm
depending on the variety, soil fertility, plant density and available moisture. Other
bast vegetable fibres include jute ,hemp, kenaf, ramie, sunn, and urena (Pringle,1949).
The physical and morphological structure of the plant revealed that the main portion
of the flax plant is the woody trunk or boon, which is hollow in the centre. This is
surrounded by the harl, which is composed of the soft bast, in which the fibres are
embedded, hence the term ‘bast fibre’ and the outer covering or epidermis. The
elementary flax fibres exhibit a polygonal shape with five to seven sides and they are
assembled into bundles of 10-40 fibres. The bundles or ‘compound’ fibres ,run the
full length of the stem and are joined to each other at intervals by insoluble gums or
pectin (Pringle, 1949; Liholt et al., 1999).
The outer covering of the flax is coated with a thin, water proof, waxy skin or cuticle.
The cuticle provides protection against microbial pathogens and water loss and is
bound to the epidermis (Batra, 1998). The cuticle barrier is difficult to remove during
retting and remains with the fibres with consequent poor quality yield leading to
problems in processing and utilization. Scutching and hackling tend to break-up the
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coarse bundle of fibres as they exist in the bast (Cook, 1984; Pringle, 1949), but do
not separate the fibre strands into their individual fibre cells.
The flax fibres consist of highly crystalline cellulose fibres spirally wound in a matrix
of amorphous hemicelluloses and lignin. They are oriented at a tilt angle of 100 to the
axis of the fibre end, hence display an unidirectional structure (Baley, 2002). The
polymer system of flax is more crystalline than that of cotton and therefore stronger,
crisper and stiffer to handle, also , wrinkling more easily than cotton. The ultimate
fibres are composed of micro fibrils which are spirally arranged with a diameter of
about 0.5 mm. The cell wall of flax fibres is thick and polygonal in cross section and
do not have the convolutions typical of cotton.
Flax plants are cultivated in various countries including Russia, China, Germany,
Poland, Ireland, France, Belgium, South Africa and Holland. There are about one
hundred species of flax known to botanists but of these only Linum Ussitatissimum is
suitable for fibre production (Cook, 1984).
Raw flax fibre consists of natural cellulosic polymers containing up to 30 % of
various non-cellulosic impurities. The impurities in the flax fibres are hemicellulosic,
lignin or woody matter, pectin and small amount of fats, waxes, protein and residual
ash. These impurities have negative effect on the fibre hydrophilic and absorption
properties (Zhang et al., 2003; Fakin et al.,2006). There are various properties of
textile fibres and they include tensile strength, fibre length, fineness, cohesiveness,
pliability, uniformity, porosity, durability, etc.
The flax fibre is the strongest of the natural fibres. However, it should be noted that
the strength of a yarn is not necessarily related to the strength of the fibre. This is
because strong fibres badly arranged or constructed can produce a weak yarn (Pringle,
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1949). The molecular structure of flax fibre is more ordered than the cotton fibre.
Because of the molecular structure, the fibre is expected to have good strength, low
elasticity, greater susceptibility to creasing and high abrasion resistance.The flax fibre
is inferior to cotton interms of uniformity, so that flax yarns are characterized by
pronounced irregularities when compared with cotton (Pringle, 1949; Kholar, 2005).
The suppleness and spinning power of flax fibre are closely related to the presence of
natural wax. The removal of the wax content makes the fibre more brittle, rough and
lusterless (Trotman, 1984). The flax fibres are good heat conductors with low heat
retention. With these properties the fabric produced from the flax would have a cool
feel during wear and would make it very suitable for summer and tropical wear. The
tensile strength of flax fibres is 6.4 N/tex compared with 3.0 N/tex to 5.0 N/tex for
cotton (Trotman, 1984). The breaking elongation of flax is 1.8 % for dry fibre, and 2.2
% for wet fibre. The flax yarn is about 20 % stronger when wet than dry (Trotman,
1984). Flax fibres differ from cotton fibres because of their longitudinal striations and
modes (Peters, 1963)
The cohesiveness of a fibre is the ability of the fibre to cling together and is chiefly
dependent on the nature of the surface of the fibres. Flax has a good cohesion in the
compound states (Pringle, 1949), yet is inferior to cotton or wool in this respect,
hence , these other fibres are much more easily handled than flax during processing.
Flax fibres are not so pliable and elastic as cotton or wool fibres, both of which
possess this property due largely to their natural crimp or waviness.
However, fabric produced from 100 % flax are noted for low crease resistance (Irish,
2005) and can be improved with newly developed wrinkle free finishes and blending
with other fibres.
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1.2 Cotton
Cotton belongs to the genius “Gossypium” of the natural order of malvacea or mallow
family. The cotton fibres are seed hairs of the cotton plant and is regarded as the
purest form of cellulose ever known (Trotman, 1984).
The plant is an annual crop grown in sub-tropical climates with different varieties
cultivated according to geographical location including Nigeria. There are five
different species of cotton namely: Gossypium barbadense, Gossypium herbaceum,
Gossypium arboretum, Gossypium hirsutunm and Gossypium Peruvianum (Rollins,
1965; Lord, 2003). However, the fibres are classified as long, medium and short
staple fibre. Important countries producing cotton include Egypt, United States of
America, India, China, Russia, Brazil, Nigeria, etc.
The major constituent of cotton fibre is cellulose with up to 89.3 – 90.5 % cellulose in
raw cotton. Other constituents include waxes, pectins, protein and cuticular matters.
Cellulose being the major constituent in cotton is a linear polymer consisting of Danhydroglucose
units joined together by β-1, 4-glycosidic linkage.
The strength of cotton fibre may be attributed mostly to the cellulose content in the
fibre and is related to a number of structural factors e.g molecular chain length and the
orientation of the cellulose. From the stand point of processing, wax is the second
most important constituent of the cotton fibre. The presence of wax is important for
the attainment of proper spinning.
1.3 Blending
Fibre blending is defined as the process of forming a fibre mixture by combining
different fibre components either of the same or different types to produce a
homogenous fibre assembly (El-Mogahzy, 2004; Membree, 1959). Blending is
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therefore important where the yarn is intended to consist of mixture of fibres. It
should be noted that each fibre has its own known characteristics and properties.
These properties may be some advantages or constraints as the case may be for a
particular fibre.
However, in order to obtain the best fabric for a particular purpose at a suitable price,
one often can achieve the desired result by blending fibres. As mentioned earlier, the
blending of the fibres leads to the attainment of a mixture of characteristics of the
individual fibres in the blended fabric.
Therefore, textile manufacturers tend to blend in order to achieve improvement in
quality and processing performance. Other advantages include reduction/control of
cost and to meet functional end-use requirements e.g. tensile and tear strength,
abrasion resistance, drape, elongation, permeability, absorption etc. Research has
shown that moisture absorption improves when flax is blended with cotton (Foulk and
Danny, 2001), On the other hand, yarn strength is often lowered or reduced when flax
is blended with cotton (Morrison and Danny, 2001). One of the reasons may be
attributed to the brittle nature of flax fibres which lack crimp and convolution to
effectively produce the necessary cohesiveness between two cellulosic fibres
(Schulze, 1998).
Another research has shown that yarns with flax fibre contents have good hygienic,
antistatic and UV-protective properties. These properties themselves are amenable to
several applications (Czekalski, et al., 2000).
1.4 Fibre Distribution in Blended Yarn Structure
The mechanical properties of staple yarns not only depends on the physical properties
of the constituent fibres but also on the yarn structures as characterized by the
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geometrical arrangement of fibres in the yarn (Hamilton, 1958: El-behery and
Batavia, 1971). When processing yarns from different blends of fibres, it is necessary
to know how the blend component are arranged over the yarn cross section. This
makes it necessary to elucidate some of the surface properties of the finished article
and to determine the relationship between the distribution of the blend components
and the properties of the fibres in the blend (El-behery and Batavia, 1971).
The fibre movement at the point of yarn formation and the ultimate position of fibres
in the yarn structure is called the fibre migration (Ramakrishnan, 2007). The
migration behavior of a fibre is affected significantly by the inherent properties of
fibre such as fibre length, fibre fineness, crimp, cross sectional shape and the inherent
characteristics of the adopted processing system. Factors such as fibre properties, yarn
properties, spinning system adopted influences fibre migration. Physical properties
such as lengths, fineness, cross sectional shape, frictional properties, fibre substance
and mechanical properties such as tensile modulus, bending modulus, tensional
rigidity, elastic recovery and extensibility influence fibre migration. Generally, finer
and longer fibres tend to move to the core and shorter and coarser fibres moves
outward and increase the yarn hairiness. The fibre arrangement in the blended yarn
affects its properties, hence the properties of blended yarn or fabric cannot be
explained merely in terms of the properties and proportions of the different
constituent fibres in the blend, the geometrical arrangement of the fibres must be
taken into account (Morton and Yen, 1952). For example, properties such as the
strength, abrasion resistance and surface appearance of the blended yarn, depend not
only on the ratio of the different fibres in the blend but, also on the relative position of
the different constituent fibres in the yarn (Hamilton, 1958). Similarly, fabric
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properties such as drape and strength are also strongly influenced by the fibre
arrangement in the blend (Hamilton, 1958; El-Behery, 1968).
Fibre distribution in yarn exhibit different characteristics depending on the system
used. The degree of fibre migration on open end yarn is much lower than ring spun
yarn. In open end rotor spinning which was used to produced the blended yarns, fibres
accumulate in rotor groove and are twisted in to yarn under very low tension variation
within a strand. At its core, rotor yarn has almost the same structure as the ring yarn
but the yarn surface consists of fibres experiencing different twists and almost no
migration. Therefore fibres in rotor yarn take part in migration to a lesser extent than
ring yarn and hence the strength realization is less than that of ring yarn
(Ramakrishnan, 2007).
In view of the foregoing development, this research is intended to explore the use of
the blended flax/ cotton of different ratios to produce fabric and investigate some of
the physical and mechanical properties of the fabric.
1.5 Statement of The Research Problem
This research work is a continuation of the research carried out by Lawal in the area
of spinning flax/cotton blend staple fibres (Lawal, 2008)
One of his major recommendations was that further research should be carried out to
convert the processed yarns into fabric. (Lawal, 2008). Therefore, this research is
intended to:
1. Convert the rotor spun yarns produced from the flax/cotton blend into
fabrics.
2. Evaluate the woven fabric produced from the blended yarns with respect to
some of the physical and mechanical properties. With these, it is expected
to give proper understanding of the parameters used on the woven fabrics.
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1.6 Objectives of the Research
1. Wind the blended yarns from the cone unto the pirns
2. Construct woven fabrics using the blended flax/cotton yarns as weft or
filling while sized cotton yarns as warp.
3 Examine some of the physical and mechanical properties of the fabrics
such as tensile strength, tearing strength, abrasion resistance,
elongation etc. in order to fully assess the quality of fabrics produced
from the different blends of flax/cotton yarns.
4. Recommend the areas that may require further research work.
1.7 Scope of Work
1. A brief introduction on the constituent fibres in the blended yarns.
2. Literature review on the various parameters to be examined under the
research.
3. Determine the various instruments to be used in conducting the various
tests.
4. Conduct a pirn winding operation using the Ishikawa-Seisakusho
winding machine from the Zaria Industries Limited.
5. Carry out weaving operations using a conventional tappet loom from
the Textile Science and Technology Department, Ahmadu Bello
University, Zaria.
6. Analyze the results with a view to identifying the best end-use of the
blended fabrics.
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