1.2 - yarn, woven fabrics, knitted fabrics, non-woven fabrics, smart textiles

Question 1

what has to be done before fibres can be woven into knitted fabrics

Answer 1

made into yarns

Question 2

how are yarns made

Answer 2

• staple fibres (staple yarns) or filament fibres (filament yarns)
• they can be manufactured with twist using a spinning process
• or manufactured without twist using a winding process: monofilament or multifilament yarns

Question 3

describe the different levels of twists

Answer 3

• low-level twist produces a weaker, softer, bulkier yarn and makes it easier to form a raised nap if the fabric is finished using mechanical brushing
• high-level twist produces a stronger, smoother and dense yarn
• too much twist causes the yarn to become crinkly. crêpe fabric has a crinkled, crisp appearance and is made using a highly twisted yarn
• plying a single yarn twisted in the S direction and a single yarn twisted in Z direction makes a balanced yarn, less likely to untwist

Question 4

what is Tex and Dernier?

Answer 4

• technical terms relating to formulae used to state a yarns thickness
• fibre type, thickness of yarn and tightness of twist all affect a yarn’s working and aethetic properties
• the choice of yarn is mostly distated by the end use of a woven or knitted fabric

Question 5

what are staple yarns?

Answer 5

• all manufactures fibres are produces as filaments but they are often cut into staple lengths to make a staple yarn. increasing range of yarn and fabric types
• hairy giving fabrics a soft, fuller handle. good insulators, mostly matt in appearance. longer staple fibres give staple yarns more lustre
• weaker than filament yarns as regularity in thickness is harder to achieve
• more expensive to manufacture, more stages and energy are required
• staple yarn can contain two or more different types of fibre
• blended to create aethetic effects and improve performance and aftercare of fabrics