By: David Vink
April 15, 2012
MARL, GERMANY (April 15,3:15 p.m. ET) — Evonik Industries AG is warning customers that supplies of some materials using cyclododecatriene feedstocks — including nylon 12 — could be constrained following a March 31 factory explosion in Marl.
Nylon 12 supplies were already constrained prior to the incident, and now auto suppliers are planning a summit to discuss the severe shortage.
Two Evonik employees died as a result of the explosion and fire at the Marl facility. The cause of the explosion is not yet known, but is subject of an investigation by North Rhine Westphalia authorities and an independent expert commissioned by Evonik.
The cause was most likely a material failure, according to an April 4 statement by police and the state prosecutor’s office. Damage is estimated in the millions of dollars.
A gas tank containing highly flammable 1.3 butadiene exploded within the cyclododecatriene (CDT) plant at the Marl facility. Local fire services extinguished the fire after about 15 hours, in the early hours of April 1. On April 11, the company said repairs would take until the "end of the summer" to be completed.
Nylon 12 is made from the monomer laurolactam. Evonik said complete hydrogenation of CDT produces cyclododecane, a chemical intermediate that is converted in a number of synthetic steps to laurolactam.
Aside from Evonik, there are other CDT plants in operation, including plants in France, the United States and Japan. CDT also is used to make brominated flame retardants for plastics such as polystyrene.
Evonik uses CDT to produce its Vestamid L range of nylon 12 compounds, Vestamelt adhesion promoters, Vestosint sintering powders for coatings and Vestenamer semi-crystalline rubber.
Other nylon 12 suppliers such as Arkema Group (with its Rilsamid-brand nylons), Ube Industries Ltd. (Ubesta), EMS-Grivory (Grilamid L) may also be affected directly or indirectly by more limited supply of CDT and/or laurolactam — as well as from increased demand from Evonik’s traditional customers.
The shortfall in nylon 12 supply can be accommodated by users to some extent, Evonik suggests, by switching to products from its Vestamid Terra range, which can be modified to achieve “much the same” properties as nylon 12.
Vestamid Terra consists of nylon 6/10, nylon 10/10 or nylon 10/12 polymers obtained partly or entirely from castor oil.
That said, Evonik stressed, "We do expect there to be substantial constraints with respect to our ability to provide supplies of CDT-based products."
Applications for nylon 12 include some athletic shoes, coatings for optical fibers, cable conduit and profiles, low smoke halogen-free flame retardant insulation for copper wire, and natural gas network pipe applications.
A recent strategically important application is use of Vestamid nylon 12 for the selective catalytic reduction (SCR) lines used to reduce nitrogen dioxide emissions from diesel engines. In this application, the material must be hydrolytically stable, resistant to the Adblue 32.5 percent aqueous urea additive used at up to 60°C in SCR lines, and resistant to ammonia and gas mixtures flowing back from the catalyst.
It is here in the automotive industry that concerns have already started to build related to the reliability of nylon 12 supplies for makers of products including fuel and brake-line coatings, flexible hoses and quick connectors.
Auburn Hills, Mich.-based TI Automotive, for example, uses nylon 12 for brake and fuel lines and fuel system components supplied to most major automotive OEMs in the United States. The company is so concerned about a severe shortage that it has it has organized an emergency summit on April 17 with its competitors Cooper-Standard Automotive, Martinrea International and Rayconnect, according to an April 13 report from Bloomberg.
According to the Bloomberg news report, TI fears that it means not just the United States, but the global automotive industry, facing possible interruption of production “in the next few weeks."
TI Chairman William Kozyra has already written a warning letter to customers. There is concern that automotive OEMs are not yet aware of the supply difficulty among their suppliers, and that plastics processors that operate on just-in-time inventory levels could soon run into supply chain problems.
Nylon 12 has indeed been making significant inroads into automotive applications, being described by EMS-Grivory with its density of 1.01 as the lightest of all polyamides.
Arkema has for example revealed that its Rilsamid nylon 12 material has been particularly successful in French and Japanese car models.
Arkema and Evonik have already announced plans to expand nylon 12 capacity. Arkema announced in November 2010 that it planned to triple its Rilsamid nylon 12 and Rilsan nylon 11 Asian production capacity in Shanghai to a total of 6,000 metric tons per year. That project was due to start up in the first half 2012, but will not reach full capacity until 2013.
Evonik in December 2010 had announced a capacity increase in Marl, and in December 2011 it also announced plans for a 20,000 metric ton per year nylon 12 facility in Asia, scheduled for completion by the end of 2014.
Nevertheless, there was still concern about tight nylon 12 supplies in 2011. For example. Polyadvanced, a German company producing polyurethane flexible hoses in the Czech Republic, introduced high density polyethylene-coated PU hoses with improved UV resistance, not only aimed as a less expensive solution to substitute nylon 12 hoses, but as a means of countering short supply of nylon 12.