Unit 2 - Lecture 12 Topic 1

Question 1

Acrylic:

Answer 1

Made from acrylonitrile, acrylic is a co-polymer, as another monomer is incorporated into the polymer chain. Acrylic is a manufactured fibre in which the fibre forming substance is any long-chain synthetic polymer composed of at least 85% by weight of acrylonitrile units. It can be manufactured by wet spinning or dry spinning.

Question 2

What is the cross-sectional shape of acrylic?

Answer 2

Dry spun acrylic looks like a dog bone while wet spun is shaped more like a lima bean.

Question 3

How does acrylic compare in marketing to wool?

Answer 3

Acrylic is often marketed as a wool alternative as it is less expensive and easier to care for. The low density fibre has adequate elastic recovery but it is still lower than wool. Acrylic also has low moisture absorbency.

Question 4

Polypropylene:

Answer 4

Polypropylene is a type of olefin fibre (Polyethylene is also an olefin fibre but used less in textiles). It is a thermoplastic fibre that is melt spun and it’s cross-sectional shape can vary depending on the spinneret

Question 5

Polypropylene:

Answer 5

Polypropylene is a type of olefin fibre (Polyethylene is also an olefin fibre but used less in textiles). It is a thermoplastic fibre that is melt spun and its cross-sectional shape can vary depending on the spinneret.

Question 6

How heavy is polypropylene?

Answer 6

Polypropylene is a lightweight hydrophobic fibre with a specific gravity of 0.92- making it lighter than water.

Question 7

What is polypropylene used for?

Answer 7

Used for a wide variety of applications such as apparel to industrial products. Commonly used in nonwovens (eg, diapers, industrial filters) and it’s a major fibre used in carpet backings. It’s also used in active and thermal clothing due to good wicking capability and is low density therefore providing warmth without weight.