Fibres - Part II - Short Answer

Identify THREE properties that make cotton fibre a suitable choice for bath towels.

Answer explanation

Criteria Marks

Recognise and names three (3) appropriate fibre properties that make cotton fibre a suitable choice for bath towels 3

Recognise and names two (2) appropriate fibre properties that make cotton fibre a suitable choice for bath towels 2

Provides one (1) appropriate fibre property that makes cotton fibre a suitable choice for bath towels 1

The properties change in accordance with the usage, purpose and environment of the end- use. It is about identifying the most appropriate properties.

Answers include:

- Absorbency: cotton is a highly absorbent fibre. The cellulose in cotton is referred to as “hydrophilic properties,” meaning water loving or water attracting. Cotton is naturally a hollow fibre making cotton suitable for a towel because it is breathable and absorbent.

- Durability: good strength which increases when wet; cotton is 70% crystalline and 30% amorphous, so this contributes to the fibre strength.

- Thermal properties: comfort; cotton is a smooth fibre that does not irrate the skin and has a soft hand feel against the skin.

Explain how the morphological and molecular structures of wool fibres are suitable for the end use of high-performance sportswear.

Answer explanation

Criteria

Marks

Provides in detail how the morphological and molecular structures of wool fibres are suitable for the end use of high-performance sportswear

3

Briefly provides how the morphological and molecular structures of wool fibres are suitable for the end use of high-performance sportswear OR identifies and provides in detail how ONE structure is suitable for the end use of high performance sportswear

2

Names either the morphological and molecular structures of wool fibres OR only briefly provides detail on how one or the other structure is suitable for the end use.

1

Morphological – physical characteristics i.e. stable fibre; crimp and scale structures

Molecular – amorphous and crystalline regions and structures

Answers may include: The morphological structure of the proteins in wool such as the crimp or wavy fibre structure provides flexibility, elasticity, resiliency, and good wrinkle recovery properties. It can be used to make the finest woven and knitted fabrics used in high performance sportswear that provides excellent insulating properties due to the overlapping scales of the natural fibre. Wool has a primarily amorphous fibre structure, and this is responsible for wool's advantage over other fibres of absorbing a relatively large amount of water/or perspiration without the wearer feeling wet. The molecular structure of the fibre provides excellent moisture absorbing properties that make fine wool products extremely comfortable to wear under most conditions as it can react to changes in body temperature. It also has excellent elasticity and resilience as it will stretch with the body and return to its natural shape due to the crimp in the fibre. Wool can be soft against the skin preventing irritation from constant movement in a high performance sport, especially when the wool is a superfine merino wool. It can provide a high UV protection from the sun; which makes it excellent for a wide range of outdoor activities. The chemical composition of wool also enables the fibre, yarn or fabric to be easily dyed to shades ranging from pastels to full, rich colours during the production process.

Explain why the properties of silk make it a suitable choice of fibre for a decorative cushion?

Answer explanation

Criteria

Mark

Clearly provides appropriate relationship between silk and it’s use as a decorative cushion, using properties

4

Provides appropriate relationship between silk and it’s use as a decorative cushion, using properties

3

Provides appropriate information for silk and it’s use as a decorative cushion, using properties

2

Provides some relevant information

1

Answers may include:

Silk has beautiful natural lustre which in a decorative cushion provides the aesthetic interest required visually. The absorbency of silk will provide a platform for the product to have a specific colour range specific to the room without losing its natural lustre. Having some elasticity provides the cushion with a comfort factor allowing the user to be comfortable. The washability of silk is also important although it may not require lots of cleaning being decorative. Silk is relatively strong and given a cushion stretches around an infill it will hold it’s shape very well. The resiliency is not great but again being a decorative cushion, should not be an issue as it is not going to be leaned on or scrunched as it does have the infill.

Name a suitable fibre for a winter beanie and justify your choice. 

Answer explanation

Criteria

Marks

Clearly supports an argument for an appropriate fibre

2

Provides some information for an appropriate fibre

1

Answers may include: Wool Fibre. As wool has very good thermal properties, this will provide insulation to the wearer to stay warm, during the cold winter months. As wool is amorphous in structure it is also able to absorb dye to provide the bright colour.

Explain how the properties of a nylon elastomeric blend make it suitable for a swimming costume.

Answer explanation

Criteria

Marks

Clearly relates cause and effect providing appropriate properties suitable for a swimming costume

4

Relates cause and effect providing appropriate properties suitable for a swimming costume

3

Sketches in general terms some appropriate properties suitable for a swimming costume

2

Names an appropriate property suitable for a swimming costume

1

Answer may include: A blend is best for a swimming costume as the suit requires elasticity for movement, comfort properties as the garment is worn next to the body. Quick drying so the costume remains comfortable to the wearer, the hydrophilic nature of both nylon and elastomeric is an excellent choice for these reasons. Nylon can be modified to provide a fibre with a soft and smooth surface and blends well with elastomeric to enhance these properties. Nylon may be coloured at fibre stage to create a swimming costume with vibrant colour if required. The elastomeric enhances the comfort of wearing as it provides stretch and provides movement to the wearer.

Justify why nylon fibre is a suitable choice for outdoor furniture.

(2 Marks)

Answer explanation

Criteria

Marks

Clearly justifies properties suitable for the use of nylon

2

Identifies a reason for use of nylon

1

Suggested answers may include:

Shrink resistant, excellent dimensional stability, relative inelastic providing support also a strong fibre allowing for various weights to be applied. Outdoor furniture requires prolonged exposure to the elements and therefore nylon provides these characteristics. It is smooth and therefore comfortable to sit on and can be shaped due to its thermoplastic nature creating seats that maybe moulded to the body shape.. Can be coloured at fibre stage to provide a good range of colour choice.

Blended fibres are used for specific purposes. Identify and justify a suitable blended fibre that could be used for a gymnastic leotard.

(2 Marks)

Answer explanation

Criteria

Marks

Identifies an appropriate blended fibre and clearly justifies reasons for its use

2

Identifies an appropriate blended fibre and/or provides a reason for its use.

1

Suggested answers may include:

Nylon / elastomeric blend – Because of its high lustre in the nylon, good drape, excellent strength and elasticity makes this appropriate for the expanded movement and visual importance for a gymnastic leotard. Elasticity provides movement therefore comfort, with good abrasion resistance important to provide longevity for the leotard’s constant activity. Aesthetics are important for the wearer and this blend provides good colour choice with good colourfastness.

Identify THREE properties that make nylon fibre a suitable choice for an umbrella.

(3 Marks)

Answer explanation

Marks

Criteria

3

Outlines three properties

2

Describes three properties in varying amounts of detail

1

Names three properties or briefly describes one

Answers may include-excellent abrasion resistance; fairly resistant to sunlight; low absorbency; excellent dimensional stability; colourfast; some elasticity; strong

Explain how the morphological and molecular structure of nylon fibres make this fibre suitable for the end use of an umbrella.

(3 Marks)

Answer explanation

Marks

Criteria

3

Explains how the properties suitability for the umbrella

2-1

Names TWO or ONE property

Answers may include that nylon is crystalline in structure which gives strength and resilience; it can have a variety of cross sectional shapes

Identify a fibre blend that would be suitable for use in a pair of yoga pants.  Justify your choice. 

(2 Marks)

Answer explanation

Criteria

Mark

Correctly identifies a fibre blend and justifies with relevance to end use

2

Identifies a fibre blend and outlines relevance to end use

1

Answers may include:

• • Cotton & elastomeric, it has excellent stretch allowing for free movement as required for yoga. Comfortable as cotton is absorbent, drawing moisture from the body. Good resilience allowing the garment to retain its shape.

• Polyester and Elastomeric: resilience, elasticity, comfort in movement, strength.