Study Unit 9: Manufactured non-cellulosic: Modacrylic

Question 1

History

Answer 1

The first modacrylic fibre, Dynel®, came onto the marketing 1949. Modacrylics are made from acrylonitrile (at least 35–85%) and another chemical, such as vinyl chloride.

Question 2

Fibre Production

Answer 2

The polymer that is formed is dissolved in acetone then spun in warm air to allow the solvent to evaporate. Because of this, modacrylic garments should never be cleaned with nail- polish remover or any other acetone-containing cleaner.

Question 3

Properties

Answer 3

The properties of modacrylics are fairly similar to those of acrylics. The most important property of modacrylic is that it does not support combustion. The fibres are difficult to ignite and are self-extinguishing. No dripping occurs and a hard black char remains.

Question 4

End Uses

Answer 4

Modacrylic fibres are used for fur-like fabrics (“fake” furs), wigs and hairpieces and children’s sleepwear.
Two types of modacrylic fibre, each possessing a different crimp and shrinkage potential, can be mixed when making a fur fabric.

After heat treatment the one type will shrink more and form soft, highly crimped undercoat fibres while the other will form long, polished fibres (guard hairs), much like real fur. Dunova ® is a porous acrylic fibre contains many micro-capillaries which are able to absorb liquids. It is used for warm and absorbent underwear.

Question 5

Care

Answer 5

Modacrylics can be washed or dry cleaned, although care must be taken to minimise rubbing because of the formation of pills. They are resistant to acids, weak alkalis, most organic solvents and mildew and insects.