Fibre in general Flashcards
1
Q
What is a fibre?
A
a long, thin, flexible, hair-like thread
2
Q
What is a staple fibre?
A
short in length, spun into staple yarns
3
Q
What is a manufactured yarn?
A
produced from melted, plastic chips
4
Q
What is the synthetic fibres needed to be studied?
A
Polyester
5
Q
What is the regenerated fibre needed to be studied?
A
Rayon
6
Q
What is the cellulosic fibre needed to be studied?
A
Cotton
7
Q
What is the protein fibre needed to be studied?
A
Wool
8
Q
What is a short fibre called?
A
Staple
9
Q
What is a long fibre called?
A
Filament
10
Q
What does a higher denier (weight of fibre) mean?
A
A more durable fabric
11
Q
Chemical composition of wool
A
Protein
12
Q
Chemical composition of cotton
A
Cellulose
13
Q
Chemical composition of Polyester
A
Polyester
14
Q
Chemical composition of rayon
A
regenerated cellulose
15
Q
what is the porcess called when molecules join to form a chain?
A
Polymers
16
Q
What is an amorphous region?
A
It is when the polymers in a fibre have large distances aart from ech other and are in random arrangements
17
Q
What is a crystaline region?
A
Polymers are packed together to form parallel arragements
18
Q
fibres that are highly amorphous:
A
Wool, rayon
19
Q
fibres that are highly crystaline:
A
Cotton, Polyester
20
Q
Why did synthetic fibres evolve?
A
Due to the desire to create stronger, more versatile materials that have better properties that natural fibres.
21
Q
How do regenerated fbires differentiate from synthetic fibres?
A
Regenerated fibres are fibres made from different parts of cellulose plants and solidified in chemimcals, however, synthetic fibres are fully made from chemical man-made materials.
22
Q
fibre classification for cotton:
A
Cotton is a natural, cellulose fibre derived from a cotton plant. It is highly crystaline and thus very strong. it is cream or white in colour which contributed to the overall lustre.
23
Q
Cotton morphlogy:
A
- Twisted in shape
- kidney bean shape
- fibres vary in length (1-2 inches)
- it is a staple fibre meaning it is short in length
24
Q
What is diametre of Cotton?
A
12-20 micrometres
25
Why does cotton have an increased surface area as it has a big diametre?
because then it is able to absorb colours and other things much quicker as a result of it's twisted shape.It also enhances the bulkiness of the fabric.
26
What happens to a Cotton fibre when it gets wet?
It gets stronger
27
What is the primary cell wall in a cotton fibre?
- made of cellulose
- provides strenbth and flexability
28
What is the secondary cell wall in a cotton fibre?
- more crystaline thus more strong
29
What is the lumen in a cotton fibre?
- hollow centre of the fibre
- holds moisture and air for breathability
30
Fibre classification of wool:
Wool is a natural protein fibre.
31
What is the difference between Merino wool and coarse wool?
Merino wool = fine, soft fibres used in high quality clothing
Coarse wool = thicker fibres, used in carpets and heavy garments
32
What is the diametre of a wool fibre?
fine wool = 18-34 microns
coarse wool = can exceed 30 microns
- finer the wool the softer and more comfy on the skin
33
Exterior structure of wool:
- scales that help with moisture and insulation
- scales can cause wool to be itchy
- overlapping scales called cuticle cells
- provide tough exterior and prevent damadge
- waxy coating making it water repellent but still allowing absorption
34
Cuticle cells explanation of wool structure:
- jagged edge becuase of exposed cuticle cell structure
- allows fibres to slip over one another easily
35
Felting in relation to wool structure:
when wool fibres are agitated in water, the scales interlock preventing the fibre from returning into its original shape. thius can create more dense fibres and can unintentionally be made by bleaches.
36
Interior structure of wool:
- cortex is a long, overlapping, tapering of cells surrounded by the cell membrane complex.
- it is made from proien and waxy substances.
37
Rayon fibre classification:
a regenerated, cellulosic fibre.
38
What is Viscose rayon?
- dissolved in cellulose, sodium hydroxide, and carbon disulfide
versatile and soft as well as most common
39
What is Modal rayon?
- Bleached tree pulp that is silky
- stronger and more durable than other rayons.
40
What is Lyocell rayon?
- wool pulp
- produced through a more enviromentally friendly process
- stong and biodegradable
- used in active wear and denim
41
What is the cross-section fo rayon look like?
Oval or circular, smooth furface that helps fabric softness and lustre
(depends on production process and spinneret used).
42
What is the morphology of rayon?
- long and slender with a smooth surface
- known as a filament fibre but can be cut into short lengths
- made up fo cellulose chains making it a highly amorphous fibre.
43
Why is rayon absorbent and comfy?
because it has highly amorphous regions and the cellulose in rayon makes it holds moisture.
44
Fibre classification of polyester:
Polyester is a synthetic fibre made of ployester.
45
Cross sectional shape of polyester:
- round or trilobal shape
- modified for different applications
46
Surface texture of polyester:
- smooth and glossy
47
Crystaline regions of polyester:
- it is both crystaline and amorphous but mostly crystaline.
- affects the strength and flexability fo the fibre.
48
Orientation of polyester: (in a line)
highly orientational which affects strength and durability.
49
How is polyester made?
- derived from polyethylene terephthalate
- made because of the chemical reaction of petroleum, water and air.
- thermoplastic meaning it can be meteld and soilidified.
- pushed through spinneret.
50
Chemical composition of Polyester:
- long chain of polymer, formed through the polymerisation of ethylene glycol and terephthalic acid.
51
What are the polymer chains like in polyester?
- linerar, highly orientational, and crystaline.
52
Polyester is hydrophobic or hydrophillic?
Hydrophobic making it resistant to water absorption
53
wool - lustre:
No, matte apperance
54
Wool - drape:
Perfect, good for furnishing and apparel
highly versatile - it can be made into many different objects with drape.
55
Wool - Abraison resistance:
Moderate due to fibre contstruction
56
Elasticity - wool
Excellent
57
Strength - wool
Bad due to amorphous regions. The coarser the wool in diametre the stronger it is. good for carpets.
58
Absorbency - wool
Good due to amorphous regions therefore comfortable in most conditions
59
Thermal properties - wool:
Warm fibre as it is a poor conductor of heat but has excellent insulation properties.
- can be shaped by heat or moisture but can scortch easily at high temps
- self-exstingushing
60
Dimensional stability - wool:
- bad
61
Effects of chemical - wool:
weakened by bleaches
62
Sun resistance - wool:
yellows overtime and weakens fibre
63
Colour fastness - wool:
- good due to amorphous structures
64
shrink resistance - wool:
poor because it mattes together when wet to form felt and is thus weaker.
65
Cotton - lustre:
no
66
Drape - cotton:
poor
67
Abraison reistance - cotton:
- moderate, denim has high because of it's twill weave
68
strength - cotton:
- relatively strong due to highly crystaline regions and become stronger when wet
69
Absorbency - cotton:
- highly absorbent, hydrophillic in nature.
70
Elasticity - cotton:
- no because of crystaline regions
71
thermal properties - cotton:
- good conductor of heat thus a cool fibre because it draws heat away from skin
- breatehs easily because of the lumen
- burns quickly because made for cellulose
72
effect of chemicals - cotton:
- harmed by strong acids
73
Dimensional stability:
- retains shape due to inelasticity of fibre, will not turn to original size if stretched.
74
sun resistance - cotton:
- not easily damadged thus amde into curtains, tents and other.
75
Colour fasteness - cotton
Hydrophillic so easily dyed.
76
polyester - lustre
- depends on the cross -sectional shape
77
Lustre- rayon:
- very lustrous
78
Drape - polyester:
- good but can depend on fibre structure
79
Drape - rayon:
- good
80
Abraison reistance - polyester:
- good
81
Abraison reistance - rayon
- fair and can resist pill formation
82
Strength - polyester:
- good due to higjly crystaline features
83
strength - rayon:
- low because it is more amorphous, reduces in strength by 40-60 percent when wet
84
absorbency - ployester:
- poor due to crystaline regions
85
elasticity of polyester:
- relatively elastic because of crystaline regions
86
absorbency of rayon:
- highly absorbent because of amorphous regions
87
elasticity of rayon:
- poor due to amorphous regions
88
thermal properties of rayon:
- good conductor of heat thus a cool fibre because it is cellulosic in nature
89
thermal properties of polyester:
- poor conductor of heat but good insulator, parkas, snow jackets
90
dimensional stability - polyester:
- good can be heat set to retain shape
91
dimensional stability of rayon:
- poor
92
effect of chemicals -rayon:
- acid can deterate it
93
effects of chemical - polyester:
- resistqnt to acids and bleaches
94
sun reistance - rayon:
- sun resistant
95
96
sun resistance of polyester:
- resisatnt to sunlight
97
colour fastness of polyester -
- hydrophobic so dyed at the fibre stage
98
shrink reistance of polyester -
- low shrinkage due to hydrophobic and cyrstaline regions
99
Colour fastness of rayon:
- dependent on the dyestuff used
100
shrink resistance of rayon:
- shrinks more than cotton fabrics
