PA 6.6 – the original "nylon" – has been experiencing dramatic bottlenecks in the last few months and consequently undergone phenomenal price increases. The last time this happened was in the years 2010 and 2011. Now, a structural risk has become exposed in the value chain.

The Achilles’ heel of the most heat-resistant of the main polyamides is adiponitrile (ADN). Without this direct precursor of hexamethylenediamine (HMD), PA 6.6 cannot be produced. ADN is toxic and highly explosive, and is nowadays manufactured predominantly at four large-scale plants, each with a capacity of several hundred thousand tonnes per year. Three of them are located in the US and one is in France. In Asia, on the other hand, there are no production lines apart from a small integrated facility in Japan. China's attempt to build a plant of its own ended – at least for the time being – in 2015 with a spectacular explosion.

If all the ADN plants are up and running, an adequate, just about balanced supply of PA 6.6 production lines is ensured. However, although this scale effect makes economic sense, it also makes the chain vulnerable. Even the smallest of the large-scale plants accounts for 14% of the capacities that would be lost in the event of a malfunction. Should anything go wrong at the site in Chalampé / France, as much as one third of global production capacity would be left idle.

Last winter, Murphy's law struck with a vengeance. First of all, the historic spate of cold weather in North America brought ADN plants to a standstill from November to the end of January. Production then also stopped in France, and after only a few weeks, the European PA 6.6 chain started floundering like a fish out of water. All production lines dependent on Chalampé can only operate under major restrictions, if at all.

The plants in the US are up and running again and encouraging signals have also been received from the French plant. However, since stocks are now completely empty along the entire chain worldwide, it will inevitably take a few more months until the situation returns to normal. As a result, there is little prospect of an all-clear before the summer.

Invista is incidentally in the process of expanding its existing ADN plants because demand is growing, meaning the size of its production plants is set to increase further. In contrast, earlier plans for an Invista facility in China have been put on ice. For the time being, there is then no new plant in prospect, although it is desperately needed to safeguard the value chain. The risk of PA 6.6 stoppages is therefore still very strong, and the consequences could become even more serious than at present. From the users’ point of view, suitable alternative materials are becoming strategically more urgent.

Daniel Stricker
Head of Market Research at Plasteurope.com