Although (as shown below) there are a vast number of polymers that are collectively known as 'plastics', the majority have common features which make coating difficult. This article reviews some of the applications, problems and ever-improving range of solutions associated with the coating of plastics. A number of issues which are relevant, such as printing of food packaging have been discussed in previous articles and will not be repeated here.
The English language unfortunately applies the term 'plastics' to both thermoplastic and thermoset polymers. The latter do not have the same surface characteristics as thermoplastics and provide a high-performance damage-resistant surface whichserves as a decorative finish. Accordingly, the focus here is almost entirely on the specific problems and applications of applying paints to thermoplastic substrates. Europe and North America each account for approximately 25% of world plastics production and consumption, while Asia (excluding Japan) accounts for 30%.