STUDY UNIT 10: Polyolefin

Question 1

Olefin fibres

Answer 1

An olefin is a manufactured polymer in which the fibre-forming substance is any long-chain synthetic polymer composed of at least 85% by weight of ethylene, propylene or other olefin units.

Question 2

Olefin has taken over what markets and why?

Answer 2

Olefin fibres have largely taken over the markets once dominated by jute and sisal.
The main reason for the interest in olefin fibres, polyethylene and polypropylene, is their low cost and high strength.

Question 3

Olefin fibres are made from what by-product?

Answer 3

Olefin fibres are made from the petroleum by-products ethylene and polypropylene gas.

Question 4

Describe the durability, comfort and resilience.

Answer 4

The fibres have high durability, moderate comfort and excellent resilience.

Question 5

Eplain the shrinkage

Answer 5

However, the fibres are heat and light sensitive and have poor dyeing capacity. They shrink at temperatures as low as 75 oC.

Question 6

Polyethylene are produced as:

Answer 6

Polyethylene fibres are produced as monofilaments or split film.

Question 7

Polyethylene Uses

Answer 7

Polyethylene fibres are widely used in industrial fabrics, ropes, nets and filters but not for garments or home furnishings.

Question 8

Polyethylene Heat resistance

Answer 8

Polyethylene melts at 105 oC. As the lowest temperature possible on household irons exceed 100 oC, polyethylene fibres are generally used in products that do not require ironing

Question 9

Can Polyethylene be dyed and why?

Answer 9

The fibres are hydrophobic and cannot be dyed by normal techniques.

Question 10

Polyethylene abrasion resistance

Answer 10

Good

Question 11

Polyethylene elastic recovery

Answer 11

Excellent

Question 12

Polyethylene and acid

Answer 12

They are resistant to acids and alkalis.

Question 13

Explain the bright white Polyethylene

Answer 13

In a modified process, a bright white polyethylene can be produced which is, pound-for- pound, ten times stronger than steel, more durable than polyester and has a specific strength that is 40% greater than aramid fibre.

Question 14

Uses of Spectra

Answer 14

Spectra® is best known as the super-fibre used in the Small Arms Protective Insert (SAPI) plates for soldiers. It is also used in numerous high- performance applications, including police and military ballistic-resistant vests, helmets, sailcloth, fishing lines, marine cordage, lifting slings, cut-resistant gloves and apparel.

Question 15

Polypropylene fibres are produced as:

Answer 15

Polypropylene fibres are produced as both filament and staple fibres

Question 16

Polypropylene heat resistance:

Answer 16

Polypropylene melts at 170 oC. Polypropylene fabrics should be ironed at the lowest iron setting.

Question 17

Polypropylene abrasion resistance:

Answer 17

Good

Question 18

Polypropylene elastic recovery:

Answer 18

Excellent

Question 19

Polypropylene The fibres are hydrophobic. True or False

Answer 19

True

Question 20

Polypropylene End Uses

Answer 20

Polypropylene fibres are used for carpeting, drapery and upholstery fabrics. They are also used for carpet tiles of the indoor-outdoor type for kitchens, bathrooms and even around swimming pools, and for sports undergarments.