Yarns Flashcards
What is a “drawing” process
The process in which gives synthetic fibres their strength because the chain of molecules become oriented and lie parallel when it’s turning from liquid to solid
It is difficult for water molecules to penetrate between tightly packed fibre molecules in crystalline. True or false.
True
What is extensibility
The measure of how much a fibre will stretch or extend before it breaks
What is crystalline regions
High orientation areas
What are amorphous regions
Low orientation areas
Fibres with lots of crystalline regions tend to be…
Stiff and inflexible
If a fibre has a mix of crystalline and amorphous regions the fibre is able to be….
Stretched or bent
Fibre properties are related to the internal fibre structure. Name three
- Strength
- Ability to absorb moisture
- Extensibility and elastic recovery (crease)
What are three industrial spinning processes called?
Wet, dry and melt spinning.
Why are fibres needed to be made up into yarns?
So they can be woven or knitted into fabric.
How are continuous filament yarns made?
By lightly twisting filament fibres together.
How are staple yarns made?
These short staple yarns have to be carded or combed so that they all lie in the same direction, before being twisted together to form a yarn.
Filament fibres can be chopped up into short staple fibres. True or false.
True.
Staple yarns create hairy yarns. Why is this good?
They trap air between the fibres, so they can insulate well and trap moisture between the fibres too! Smooth yarns have the opposite effect.
If a fabric is to be brushed, the yarn has to be twisted more. True or false.
False. The yarn has to have a low twist.
