Making things out of plastics is like playing a game withmolecules. The aim is
to re-organise them into new shapes withouttheir changing colour, sticking to
the mould, or doing anythingthat could spoil the finished article. Additives
help with allthese problems. In fact, processing plastics without additives
isvirtually impossible. Consider the range of plastics available andthe wide
variety of plastic objects in every day use. From fizzydrinks bottles and
carrier bags to window frames and computers, itis clear that there are many
different ways of forming plastics.Most of these processes involve melting
polymer powder or granulesinside a heated tube. This‘melt’ is forced through
ashaped die, injected into a mould,