Saturday, 21 May 2016

Fibres and Fabrics: properties and formation

Fibres are the basic building blocks of fabrics. The fibres are twisted or spun together to form a yarn before a fabric can be made.
Fibres - Yarns - Fabrics

Natural fibres- come from plants and animals (protein and cellulose fibres)
Synthetic fibres- all man made from coal and oil
Regenerated fibres- partly made from chemicals, partly from natural things. Made from natural cellulose e.g. wood pulp - man made

Natural fibres-
- cotton (cellulose, seed)
- wool (protein)
- silk (protein)
- hair (protein)
- linen (cellulose, bast)
- ramie (cellulose, bast)

Regenerated fibres-
- viscose (Rayon)
- Modal
- Acetate
- Lyocell (Tencel)

Synthetic fibres-
- polyamide/ nylon (Tactel)
- polyester (trevira, polar fleece/ terylane)
- acrylic (courtelle/ amicor)
- elastane (lycra)

Staple fibre- a short fibre
Filament fibre- a long fibre

Bast fibre- from the stem of a plant e.g. hemp
Leaf fibre- from leaf of a plant e.g. sisal, pineapple, banana
Seed fibre- from seed of a plant e.g. coir

Cotton:
- cellulosic
- grows inside seed pods which burst open to expose the cotton fibres
- a staple fibre

Advantages
Disadvantages
strong, especially when wet
can be washed regularly at high temperatures
good moisture absorption (good for active wear)
breathable
can be bleached
hard wearing- good resistance to abrasion
inexpensive
soft handle
easy care
good drape
good absorption means staining
can shrink
very flammable
creases badly
will go mouldy if left damp
dries slowly

Linen:
- cellulosic
- fibre is known as flax and called Linen once made into a fabric
- staple fibres

Advantages
Disadvantages
Cool fibre
Strongest natural fibre both wet and dry- washes well
Hardwearing
Lustrous and lightweight
Soft firm handle
Absorbent by dries quickly
Dirt repellent
easy care
Creases badly
Shrinks up to 15%
Very flammable


Ramie:
-cellulosic
-comes from stem of nettle plant
- used for rope, twine, and commercial products
- staple fibre
- silky in appearance

Advantages
Disadvantages
Strong- both wet and dry
Highly absorbent
Gets smoother when washed
comfortable
can be washed
creases easily
stiff brittle fibres
expensive
stiff- doesn't drape well
not durable
little elasticity

Wool:
- protein fibre
- from fleece of sheep
- staple fibre - creates a warm fuzzy fabric
- has a crimp - a wavy structure- can be pulled and will snap back into place - stretchy 
- used for knitwear, jumpers, scarves

Advantages
Disadvantages
Soft full handle- fine wool
Warm- many air pockets trapped between fibres
Hydrophobic- water resistant- direction of scales allow water to run off
Resistant to burning- high moisture
Crease resistant
Hydrophilic- absorbs without feeling wet
good drape
good elasticity
Will shrink- scales interlock and felt creating a matted fabric
coarse wool- scratchy
The woolmark- indicates a product is made out of 100% wool











Silk:
- protein fibre
- comes from cacoon of a silk moth/ worm
- continuous filament fibre
- used for luxury products, haute couture, lingerie, wedding dresses, evening wear

Advantages
Disadvantages
Very smooth and lustrous
Good draping qualities
Absorbent- takes dye well
Cool in the summer, warm in the winter
very comfortable
soft handle
good strength
expensive
creases easily
easily damaged by perspiration/sunlight
needs to be dry cleaned or carefully handwashed
weak when wet

Hair:
- protein fibre
- regarded as rare and expensive
- all from animals
Cashmere- from goat
Mohare- angora goat
Vicuna- from camels
- adds to luxury appearance/ handle of the product
- usually blended with other fibres

Advantages
Disadvantages
Warm
Lightweight
Very fine smooth fibres
Soft texture and handle
Easily damaged by perspiration or sunlight
Needs dry cleaning or careful hand washing
Mohair- angora goat:

Advantages
Disadvantages
Warmer than wool
Lustrous
Light
Luxury handle
Good drape
Durable
Crease resistant
Poor absorbency
Extreme care


Asbestos:
- mineral fibre
- now restricted due to health hazard
- used to be used where heat protection was required e.g. theatre curtains
- non flammable
- resistant to chemicals

Viscose:
- regenerated cellulosic
-made from wood pulp

How it's made:
- Cellulose sheets are placed in a bath of caustic soda
-both are shredded
- they are thoroughly mixed up
- more caustic soda is added to make a viscose solution
- solution is stored until needed
Advantages
Disadvantages
Highly absorbent
Soft
Comfortable
Good drape
Not strong
Creases easily
Not warm

Modal:
- regenerated cellulosic
-made from wood pulp
- often blended
Advantages
Disadvantages
Highly absorbent
Soft
Comfortable
Good drape
Soft handle
Easy care
Low shrinkage
Not strong
Creases easily
Poor elasticity

Lyocell:
- regenerated cellulosic
- made from wood pulp
- branded as tencel
- like cotton but very eco-friendly
- high strength
- absorbent
- breathable
- low shrinkage

Cupro:
- regenerated cellulosic
- made from wood pulp
- breathes like cotton
- drapes beautifully
- feels like silk on your skin
- an elegant fabric

Acetate:
- regenerated cellulosic

- made from wood pulp
Advantages
Disadvantages
Fast drying
Soft handle
Smooth
Drapes well
Low absorbency
Low warmth
Creases easily
Not strong

Rubber:
- regenerated cellulosis
- made from wood pulp
- stretchy
- non-slip
- can be printed onto parts of garment

Polyamide/ Nylon:
- synthetic fibre

Advantages
Disadvantages
Very strong
Very durable
Easy care
Dries quickly
Crease resistant
Hydrophobic- water resistant
Thermoplastic- can be molded when heated
Non- absorbent
Prone to static
Melts with heat
Low warmth
static

Acrylic:
-synthetic fibre

Advantages
Disadvantages
Soft
Wool like
Warm
Fast drying
Strong
Crease resistant
Good drape
Strong
Thermoplastic
May shrink

Polyester:
-synthetic fibres

Advantages
Disadvantages
Fast drying
Strong
Crease resistant
Hydrophobic- water resistant
Soft handle
Thermoplastic
Low absorbency
Low warmth
static

Elastane/ Lycra:
- Synthetic
- always blended

Advantages
Disadvantages
Adds stretch/ comfort
Crease resistant
Absorbent- dyes well
Soft
thermoplastic
Low warmth

PVC:
-synthetic
- can be used as a protective coating on fabrics

Advantages
Disadvantages
Waterproof
Strong
durable
good insulator
breathable
fast drying
Stiff/ uncomfortable
low absorbency

Microfibres- very fine synthetic fibres made from polyamide (nylon) or polyester. When made into a fabric it is very soft to touch, has excellent draping qualities and good strength- used in smart fabrics and high performance active wear

Shape and formation of fibres:
The way fibres are formed (natural or man-made) has an affect on the properties that they have. For example wool fibres naturally have scales that trap air so they are warm. 
Synthetic fibres are produced by extruding the liquid polymer solution through a spinneret into either warm air (dry spinning), cold air (melt spinning) or fluid (wet spinning). This results in long smooth continuous filament fibres.

Dry spinning: The polymer solution is extruded in a stream of warm air. This evaporates the solvent and solidifies the filament. - acetate and acrylics

Melt spinning: synthetic polymer chips are melted, extruded through a spinneret and hardened in cool air.- nylon and polyester

Wet spinning; polymer solution is extruded into a chemical fluid which solidifies the filaments- viscose and acrylics

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