Additives ‘crash course’ may help reduce risk of future crashes


Photo: Dr Niall Marshall of Everspring Middle East was hosted at the 2017 Additives Workshop by Chemipol Solutions and thanked by the Johannesburg company’s MD, James di Blasio

POLYMER additives play a vital role in our industry but for most convertors this is virtually a no-go area: it’s just too complicated to deal with. But there’s no doubt that a better understanding of the dynamics behind the formulations could improve the potential to achieve maximum performance for manufactured products.

That possibility was fulfilled for the 90-odd delegates who attended the Polymer Additives Workshop hosted by Chemipol Solutions and its principal, Everspring Middle East, in Boksburg on 10 November.

To the uninformed, just about every plastic pellet looks exactly the same, but we in the industry – the better informed, hopefully – know this is certainly not the case. In fact, the scientific formulations are seriously complicated and finding the best combination from the various additives in play is a job fit for lengthy scientific research.

At the workshop, Dr Niall Marshall of Everspring put delegates’ minds at rest right away, explaining simply what the main factors are in what was virtually a polymer science ‘crash course’. Carbon, oxygen and nitrogen are the main players and chain length is the defining characteristic for polymers.

Having taken that step, Marshall, who is originally from South Africa but now based in Bahrain, outlined the main variables that additives are intended to achieve – to modify, protect and improve performance. It’s a game of compromises since adjusting one of these can have an adverse effect on the others, so there is a need to proceed with caution.

Starting from the premise that additives can have a positive or negative effect, where an adverse effect can be caused by the introduction of another, the obvious goal is to eliminate negative effects on performance.


Degradation and stabilization

Given that degradation is inevitable, stabilizing additives to extend lifespan and improve performance are an absolute necessity. Once more, Niall couched it in non-scientific terms, giving a short chemistry course.

“Everything in chemistry is made up from 118 elements, 94 of which occur naturally and 24 of which are synthesized,” added the experienced additives specialist. The big danger is oxidization, which too is an inevitable process and can have a devastating effect on products which are intended to have a long service life. Mouldings intended for outdoor use can be severely weathered in relatively short periods, and we know all about this here at the southern tip of Africa. So, enter the picture … antioxidants! These stabilisers have a simple task: they need to work at a faster rate than the oxidation process. Various options are available and (the proof is in the pudding) it has to be said that the polymer researchers have come up with some very effective solutions in the last few years, with the performance of most plastic goods now far outstripping earlier versions.

Additive suppliers recommend that minimal levels of addition, but not less, be the standard rule: too little and you don’t get the desired performance while overdosing can even have a counteractive effect.

At least personnel in R+D or the lab will have better knowledge of what is going wrong … and hopefully feed that back to the polymer or masterbatch supplier or compounder. Thanks to Chemipol and Everspring for the very useful crash course.

  • Everspring has been manufacturing antioxidants for adhesives and coatings in Taiwan since 1988. It is now a global manufacturer of antioxidants, deactivators, light stabilizers and UV absorbers, supplying these to polymer and masterbatch producers and compound manufacturers around the world. Everspring Middle East WLL handles sales for Middle East/Africa. Chemipol Solutions is the Everspring distributor for South Africa.