New halogen-free options for white goods
Sebastian Hörold , head of technical service - flame retardants for thermoplastics at Clariant Plastic & Coatings , introduces new flame retardants for polyamides in white goods
Although the market for polyamide ( PA ) continues to be driven mainly by developments in automotive and E & E applications , the use of PA in household appliances keeps increasing because of the technical performance such compounds can offer compared to other polymer materials . Due to their versatility , PA compounds will continue to replace other polymers like polyesters or some thermosets . In recent years new PAs with better thermal stability , less water uptake and partially biobased backbones have been introduced in the market and have found new applications . Other trends in PAs include more highly glass-filled ( GF ) compounds , greater use of recyclates and a higher share of flame-retarded compounds , preferred based on halogen-free and sustainable formulations . Clariant , which supplies halogenfree flame retardants ( FRs ) for PAs
Figure 1 - Glow wire test set-up
under the Exolit * trade name , has developed a very rigorous method to screen products based on 36 parameters to determine their environmental impact . Evaluated products that successfully meet the criteria are then awarded Clariant ’ s EcoTain * label . In addition , Clariant has sought to reduce its carbon footprint and use renewable resources in its manufacturing process for FRs . For instance , diethyl aluminum phosphinate , which is widely used in PAs , is now also offered in a variation based on naturally derived raw materials that leads to 100 % sustainable carbon content on a mass balance approach . These products , sold under the Exolit Terra brand , have the exact same chemical fingerprint and performance as the parent material but are more sustainable . A good example is Exolit OP 1400 , which combines sustainability ( EcoTain label , GreenScreen benchmark 3 ) with excellent FR performance , such as UL 94 V0 down to 0.4 mm , a CTI of 600V as well as proven laser-marking and laserwelding properties . Exolit OP 1400 is also available as a ‘ Terra ’ grade . At the same time , the recyclability of flame-retarded polymers is of critical concern . In a study conducted by the Fraunhofer Institute for Structural Durability & System Reliability , both PA 6 and PA 6,6 compounds with Exolit OP 1400 were subjected to multiple extrusion cycles followed by measurement of flammability and mechanical properties . Both compounds keep the UL 94 V-0 classifications and show the typical mechanical properties caused by the shortening of the glass fibres
Figure 2 - Flammability requirement according to IEC 60335-1
50 SPECIALITY CHEMICALS MAGAZINE ESTABLISHED 1981