- Flame Retardants
This year's "Fire Resistance in Plastics", with its focus on flame retardancy of plastics, once again attracted different companies along the value chain, as the development of new flame retardants and formulations is becoming more and more important due to ever more stringent flame retardancy standards and the increasing relevance of sustainability, health and environmental aspects. Participants included flame retardant and plastics producers, users and also people from research and development. In addition to first-class presentations from the above-mentioned sectors, every year companies are represented with booths where interested parties can obtain comprehensive information about their products and services.
The focus of this year's presentations was, among other topics, on the new challenges for the industry due to changing technologies such as electromobility and more stringent flame retardancy requirements.
Jonathan Crozier from Pinfa presented an overview of the challenges and solutions that electric mobility brings with it. The insights shown resulted from three Pinfa workshops (www.pinfa.org) held this year and last year in China, Japan and Germany. Due to the use of heavy batteries and the resulting need to reduce weight to increase range, more flame-retardant plastics must be used instead of metal. These include thermosets and composites, for example for battery housings, and thermoplastics for connectors, charging cables and other electronic components. Dr. Xavier Couillens and Dr. Cecile Corriol from Solvay addressed the challenges for polyamides for electromobility in their presentation. They particularly emphasized the need for cooperation between the conventional automotive industry and the electrical industry. They also gave an update on their latest developments and solutions for flame retardant connectors. Engineering plastics that meet the special requirements of electric vehicles are currently being developed and some of them are already commercially available. This applies in particular to colorability in "signal orange" and high tracking resistance (current tracking index = CTI of 600 V).
On the aspect of sustainability and environmental friendliness of flame retardants, Lein Tange of ICL Europe presented several projects and ways how plastics containing brominated flame retardants can be recycled to recover the starting monomers, bromine and the frequently used synergist antimony trioxide.
Caroline Braibant from the International Antimony Association and Karen Janssens from Campine reported on the possibilities for the safe use and recycling of antimony trioxide, which is traditionally used in combination with halogenated flame retardants. Due to a certain toxicity of antimony trioxide, the correct handling and consideration of potential hazards are essential.
Dr. Günter Beyer of Fire and Polymers reported on the possibility of using bio-based flame retardants containing both nitrogen and phosphorus units. Phytic acid, for example, which can contain up to 28wt% phosphorus, is of interest here. Besides modified tannic acid and lignin, DNA is also of scientific interest due to its nitrogen and phosphorus content.
A further approach is the use of bio-based carbon sources. Dr. Christian Battenberg from Clariant presented products in which the entire carbon content is biobased. His presentation also covered solutions for transport applications with a focus on composites with a duromer matrix and highly flame-retardant polyurethane foams. Due to the huge potential of weight reduction when using these materials, they are becoming increasingly important in the market. Other newly developed flame retardants for epoxy resins are tailored to the needs of the industry for liquid and non-powder products. This enables mass production with advanced technologies.
Hervé Feuchter of Crepim presented the results of a test study on the influence of flame retardants on flue gas toxicity and density. Twelve members of Pinfa provided application-relevant polymer samples mixed with halogen-free FSM. The test results were compared with samples containing no flame retardants and those containing halogenated flame retardants. It was found that the halogen-free samples achieved lower values than the halogen-containing samples, whereby the polymer used in each case also has a major influence on smoke gas toxicity and smoke gas density.
The possibility of recycling flame-retardant polymers was also discussed in more detail during a panel discussion. Polymers with flame retardants can be recycled from a technical point of view, but the correct sorting and separation processes as well as the logistics to provide suitable material flows in sufficient quantities are still lacking.
In conclusion, it can be said that the focus on sustainability has been well elaborated and highlighted. This is becoming increasingly important and will continue to accompany us even more in the future.