2.3.3 b classification of fibres and yarns

Question 1

fibres

Answer 1

Fibres are the raw materials of all textile fabrics.
Fibres have different properties and can be
manipulated in many ways to produce different
fabrics. An example of this is cotton, which can
be manufactured into a number of different types
of fabrics such as denim, seersucker or calico.
Therefore, to state a fabric is ‘cotton’ shows little
understanding.
Fibres are classified according to their source:
* Natural polymers: plant or cellulosic; animal
protein.
* Manufactured polymers: synthetic; regenerated.
All textile fibres (or polymers) have an inherent set
of properties, making each one suitable for specific
purposes.
The structure or shape and length of a fibre
plays an important role and is an indication of its
properties and what it can be used for.

Question 2

Stock forms for textile materials

Answer 2

Textile materials bought ‘off the roll’ are available in standard widths or stock forms.
The width of a textile material is governed by the size of the loom or knitting machine it was made on.
Standard widths are 90cm, 115cm, 150cm, 200cm and 240cm.
Stock forms of materials that have trade names are not known by the fibre content. These include jersey, drill, voile, cotton poplin, corduroy, gabardine and
tweed.
Components also come in stock forms.
Manufacturers rely on specialist component
manufacturers for their supply as it is not
commercially viable to make them ‘in-house’.

Question 3

natural polymers: plant based or cellulosic

Answer 3

These include cotton, linen, hemp, jute, bamboo,
soya and banana.
* Most cellulosic fibres have a hollow cavity which
allows for moisture/water to be absorbed and
stored. This makes them absorbent and is one of
their most important properties
The hollow cavity in the cotton
fibre allows for absorption. The
twist in the smooth fibre adds
strength.
Linen’s smooth surface gives it
a slight lustre, whilst the hollow
centre of the fibres allow for
good absorption.
The micro-holes in bamboo
fibres allow good absorption. It is
anti-microbial and prevents the
growth of bacteria.

Question 4

Natural polymers: animal and insect protein

Answer 4

These include wool/fleece, mohair, cashmere, angora, alpaca, camel, llama and silk (insect).
The most common wool fibre comes from sheep, but all animal fibres have similar properties.
Wool fibres have a natural crimp
which traps air, making wool a
good insulator. The tighter the
crimp, the warmer the wool. The
scales on it also trap air.
Wool fibres can also repel water
because of the natural grease on
the surface.
The scales on wool fibres can
hook together causing matting
or shrinkage

Question 5

Manufactured polymers: synthetic

Answer 5

These include polyester, nylon (polyamide),
polypropylene, elastane/Lycra, aramid fibres and
microfibres.
* Manufactured polymers are derived from
petrochemicals – a finite resource.
* The structure of manufactured fibres can
be changed or engineered to have specific
properties, for example microfibres and aramid
fibres.
* Synthetic polymers are generally strong, resilient,
crease resistant. However, they’re not absorbent.
* They are either thermosetting or thermoforming
and can be shaped to meet specific requirements.
* Elastane has high extensibility; up to 7 times its
original length.
* Aramid fibres are engineered synthetic fibres that
are 5 times stronger than nylon and are heat and
tear resistant.

Question 6

Manufactured polymers: regenerated

Answer 6

Regenerated polymers are cellulosic fibres that have
been chemically changed. They include viscose,
rayon, acetate and lyocell.
* Viscose comes from wood pulp from eucalyptus, pine or beech wood, but also from cotton linters.
* Regenerated fibres have many of the same
properties as natural fibres since their source is part natural.
* These fibres offer good alternatives to cotton,
linen and silk