Knitted Fabrics
Knitted fabrics are made from interlocking
loops of yarn.
There are two main types of knitting:
•WEFT KNITS
•WARP KNITS
In weft knitting the loops of yarn are linked
across the width of the fabric.
Warp knitting machine
In warp knitting the loops are linked in a
vertical direction.
Weft Knitting
Weft knitting is made using a single yarn. It can be made by
hand knitting or by machines.
Characteristics of weft knits:
• The fabric has high elasticity and stretch.
• The loops of yarn trap air which retains body heat to keep us warm.
• The right and wrong sides of the fabric look different.
• the fabrics can lose shape easily.
• Creases fall out easily.
• The fabric can unravel and ladder easily.
• Weft knitted fabrics curl up at the edges when they are cut.
Weft Knitting
Weft knitting machines being used in industry:
http://www.youtube.com/watch?v=B4qzdAdhKIo
What this looks like in slow motion:
http://www.youtube.com/watch?v=SUXkEHKD_c&feature=related
How to knit by hand:
http://www.youtube.com/watch?v=4ViZRI6oPPg&f
eature=related
Warp Knitted Fabrics
In warp knitting the yarn loops vertically up the fabric and the process
uses many yarns rather than one. The fabric does not unravel or ladder. It
is an industrial process only.
Characteristics of warp knits:
• The production system is fast so the fabrics are quick to make.
• The fabric is elastic but it can keep its shape.
• It can be cut and sewn easily as it lies flat when cut.
• It is mainly used with synthetic filament yarns.
Warp Knitting
A warp knitting machine
http://www.youtube.com
/watch?v=xrSU2XfkA
dg&feature=related
Making a narrow lace
trim
http://www.youtube.com
/watch?v=Wpx5Cubq
7oo&feature=related
Uses of Knitted Fabrics
•
•
•
•
•
•
•
•
•
Weft Knits
T-shirts
Jumpers
Cardigans
Sweatshirt fabrics
Warp Knits
Net curtains
Swimwear
Terry towelling fabrics
Patterned tights
Lace fabrics
Exam questions
Manufactured Synthetic Fibres
Learning Objectives:
•Understand the sources, properties and uses of
manufactured synthetic fibres.
• Identify the advantages and disadvantages of
manufactured synthetic fibres.
Manufactured Synthetic Fibres –
Polyamide (Nylon)
Properties:
•
Very strong
•
Hard-wearing
•
Does not
decompose (rot)
•
Melts as it burns
•
Not very absorbent
so it dries quickly
•
Crease resistant
•
Resists alkalis but
can be damaged by
acids.
•
Versatile - can be
made into many
types of products.
Advantages:
• Strong when wet
Disadvantages:
• Inexpensive
• Can be damaged by sunlight
which discolours it and
makes it weak.
• Resists bacteria
• Low absorbency
• Durable and long lasting
• Not always comfortable to
wear.
Uses:
• Clothing
• Ropes
• Carpets & rugs
• Seat belts
Fabric Names:
• Nylon
• Tactel
• Tactel Micro
Manufactured Synthetic FibresPolyester Fabric Names:
Properties:
•
Very strong
•
Can be made flame
resistant
•
Thermoplastic – can be
heat set into pleats and
shapes.
•
Does not decompose
•
Resists most alkalis but
can be damaged by
acids.
•
Versatile as it can be
made into many types of
products.
Uses:
Terylene
•Sportswear
Polar Fleece
•Ties
Trevira
•Sewing
threads
Finesse
•Medical
textiles
Miratec
Dacron
•Net curtains
•Carpets
Advantages:
• Strong when wet
• Dries quickly
• Crease resistant
• Cheap
• Resists bacteria
Disadvantages:
• Poor absorbency so
it is difficult to dye.
Manufactured Synthetic Fibres Acrylic
Properties:
•
Strong when it is dry
but weaker when wet.
•
Shrinks away from
heat.
•
Thermoplastic
•
Burns slowly then
melts.
•
Soft
•
Warm
•
Easy to wash and dry.
Uses:
Knitwear
Upholstery
fabrics
Fake fur Sportswear
Toys
Advantages:
• Warm
Disadvantages:
• Poor absorbency
• Soft
• Insulating
• Inexpensive
• Dries quickly
Fabric
Names:
Courtelle
Amicor
Manufactured Synthetic Fibres Elastane
Properties:
• Very elastic
• Lightweight
• Very strong
• Resists
chemicals
• Not damaged by
perspiration
• Aids crease
resistance
Advantages:
Disadvantages:
• Very stretchy
• Very poor absorbency
• Keeps its shape
• Always needs to be
blended with other
fibres. It is too stretchy
and elastic to be used
on its own.
• Resistant to damage by
sun and seawater
• Lightweight
• Strong
• Makes garments
comfortable to wear
Uses:
• Swimwear
• Sportswear
• Jeans
Fabric names:
Lycra
Regenerated Cellulose Fibres
Regenerated cellulose fibres
are made from wood pulp and
chemicals. They are similar to
cotton.
Names of regenerated fibres:
Viscose
Rayon
Acetate
Triacetate
Modal
Tencel
Lyocell
Uses:
Properties of Regenerated
Cellulose Fibres:
• Highly absorbent
These are environmentally
friendly fibres because they
reuse waste chemicals in
the production process.
•Lyocell is used as a
non woven fabric for
medical wipes and
swabs.
•Fashion clothing
• Washable
•Lingerie
• Soft
•Ribbons
• Smooth
•Protective clothing
• Comfortable to wear
• Drape well
• High strength when wet
Exam questions
Natural Fibres
Learning Objectives:
• Understand the sources, properties and
uses of natural fibres.
• Identify the advantages and
disadvantages of natural fibres.
Natural Plant Fibres - Cotton
Properties:
• Strong
• Absorbent
• Cool to wear
• Hard- wearing
• Creases easily
• Smooth
• Versatile
• Easy to care for
• Breathable
Fabric Names:
Calico
Drill
Corduroy
Poplin
Denim
Velvet
Advantages:
Disadvantages:
• Strong when wet
• Creases easily
Uses:
• Durable & long lasting
• Burns easily
•Soft furnishings such
as cushions and
curtains
• Not expensive
• Shrinks when washed
•Clothing such as
jeans and T-shirts
• Comfortable to wear
•Knitting yarns
• Environmentally
sustainable
Natural Plant Fibres - Linen
Properties:
• Very hard-wearing
•
Cool next to the skin
•
Strong
•
Absorbent
•
Creases easily
•
Dull lustre
• Breathable
Uses:
•Light weight
summer clothing
•Tea towels
Fabric Names:
Duck
Huckabuck
Mattress Ticking
Holland
Advantages:
Disadvantages:
•Strong when wet
• Creases easily
•Very hard-wearing
• Expensive
• Sheets
•Highly absorbent so
dyes easily
• Table cloths
•Comfortable to wear
Natural Animal Fibres - Wool
Properties:
• Warm
• Absorbent
• Low flammability
• Good elasticity so
creases drop out easily
•
Comfortable to wear
Fabric Names:
Lambswool
Merino
Superwash
Felt
Harris Tweed
Gaberdine
Uses:
• Warm outer wear
such as coats
Advantages:
Disadvantages:
• Jumpers and
cardigans
• Warm and insulating
• Blankets
• Comfortable
• Carpets
• Takes a long time to dry
as it is very absorbent
• Can be produced in a
wide range of weights of
fabric.
• Some types can be
itchy next to the skin
• Does not crease easily
• Can shrink & felt when
washed
Natural Animal Fibres - Silk
Properties:
•
Absorbent
•
Soft and
comfortable
•
Cool but also warm
and insulating when
worn in layers
•
Natural sheen and
lustre
•
Strong when dry
Uses:
• Luxury clothing
such as lingerie,
evening and bridal
wear.
• Knitwear
• Soft furnishings
Fabric Names:
Chiffon Duchess
Advantages:
• Soft, smooth and
lustrous
• Drapes well
• Comfortable to wear
next to the skin
Crepe
Organza
Dupion
Taffeta
Disadvantages:
• Expensive
•Can be weak when
wet so it needs
careful washing or
dry cleaning.
• May crease easily
Exam questions
Definition:
Regenerated fibres are made
from
wood pulp (cellulose). They
are
partly natural and partly
synthetic
as a chemical is
needed to extract
the fibres.
They way the fibres are produced differs from
fibre to fibre.
It can be done through wet spinning and dry
spinning or even melt spinning. All cellulose
fibres are either wet or dry spun or a
combination of both.
1.Cellul
ose
sheets
are
placed
in a
bath
of
causti
Wet
spin
1.The fibre
ning
solution is
pressed
through the
spinneret
2.It
enters
the
Pollution
acid
bath
Viscose currently
which
is becoming less
causes the
Prop
1.Viscose
drapes
ertie
and
s swings
beautifully and
the material is
Uses:
softer than
Jersey,
cottonsuits,
and more
dress
fabric
springy
than
and
lining.
silk.
2. It is
Viscose is a
solution
made
Which spinning
from
woodchips
process
is used
Which liquid is
to produce
the spinneret
Viscose
pollutes
Viscose?
placed
into?
the
environment
Give
anthe by
due to
example
Give
an of
products
of the
viscose fabric
False. It is a
solution
made
Wet spinning
from cellulose
Acid
sheets dipped
Carbon
into caustic
disulfide
soda.
It drapes well,
is
soft
&
It’s a filament,
comfortable
1.Lyocell is
produced from
wood pulp
cellulose. It is
marketed under
the brand name
Tencel. It is the
modern Rayon!
2.It that it is soft,
Making
process:
1.Dissolve
the wood
pulp in a coagulation bath
chemical
which
Dry/we
creates a
t
solution
spinni
Uses:
Staple fibres are
used in apparel
items such as
denim, chino,
underwear
and
Fibres blends:
other1.Look
casualfor
wear clothing,
Tencel® lyocell
even in bath
Propertie
s of
cellulose
acetate:
1.Good
toughne
Natural and
Renewable
1.It is
Viscose is a
solution
made
Which spinning
from
woodchips
process
is used
Which liquid is
to produce
the spinneret
Viscose
pollutes
Viscose?
placed
into?
the
environment
Give
anthe by
due to
example
Give
an of
products
of the
viscose fabric
False. It is a
solution
made
Wet spinning
from cellulose
Acid
sheets dipped
Carbon
into caustic
disulfide
soda.
It drapes well,
is
soft
&
It’s a filament,
comfortable
1.The production
of cellulose
acetate fibres is
clean and meets
all
environmental
regulations.
Also, acetone is
Dry
spinn
ing
Uses:
Ties, lingerie,
and bathing
suits, lining,
dress fabric.
What are
What
do
you
need
regenerated fibres
to
make
the
wood
Which
two
made out off?
pulp
into methods
a fibre?
spinning
Which products
Which
products
are
there
to
make
are made from
Which
is the
least
are
made
from
a
generated
fibre?
Acetate?
environmentally
Viscose?
Which
friendly
regenerated
fibres
Which
R.F.
have
regenerated
have
poor
good acrease
Cellulose
A
Dry/wet
chemical
spinning
Lining,
Lining,
dress
Viscose
dress
fabric &
fabric
ties &
Viscose
jersey
&
Acetate
Tencel
&
Lyocell