With two new products in its polyamide (PA) assortment, BASF reacts on the Household Appliance Standard IEC60335-1, which was recently made more rigorous. Both plastic materials comply with the very high fire-protection requirements of the new standard. Whereas Ultramid® A3X4G7 is a totally new type of PA66 with 35 percent glass fibres, Ultramid® A3UG5, containing 25 percent glass fibres and introduced at the time of the K 2004 plastics trade fair, has now been optimized specifically to comply with the new standard. Both types contain halogen-free flame retardants.
“We are now offering the electrical appliance market two products that can easily meet the new requirements over quite a broad range of component geometries, and can do so without halogen. Customers can benefit from the higher level of fire protection and what is more, they can save themselves the trouble of dismantling old appliances to recover plastics containing bromine flame retardants, a step that would be required under the Waste Electrical and Electronic Equipment Directive (WEEE) of the European Community,” explains Dr. Ralf Neuhaus, responsible for electrical & electronic applications at BASF’s Polyamide Marketing.
Fire protection – light in weight and light in colour
Even though Ultramid A3X4G7 contains 35 percent glass fibres, it is lighter in weight than comparable types found on the market containing halogen and reinforced with just 25 percent glass fibres. In contrast, the A3UG5 type has a light-coloured flame-retardant system that has just been developed for electrical and electronic applications, so that now, even components dyed in light colours can be manufactured. At the same time, thanks to its special additive system, this material is even lighter in weight than the A3X4G7 variant. Since a low density translates into a lower volume price, customers can save material and thus money. Both materials account for good mechanical properties, particularly toughness, so that it is easy to form the snap-on elements and thin walls often found in electric switches. Sampling quantities of both types are available.
Stricter standard: the glow-wire ignition test
The changes made to the IEC 60335 standard relate, among other things, to household appliances that operate without supervision and through which high currents flow (more than 0.2 A). These include switches and connectors in washing machines and dishwashers, refrigerators and ovens as well as electric motors in central vacuum systems and exhaust hoods. Plastics used in this realm have to pass the stricter glow-wire ignition test at 750°C [1382°F] either on test specimens (GWIT) or on the finished part (GWT). Up to now, any flame that appeared during the glow-wire ignition test had to go out within the testing and observation time of one minute. Now that the standard has been made stricter, no ignition is permitted at all, which makes higher demands of the flame-retardant finish of the plastics employed. Very few of the polyamides currently found on the market can comply with this stricter standard, which started being phased in as of the autumn of 2005, depending on the appliance in question.
WEEE in Europe: current status
Pursuant to the Waste Electrical and Electronic Equipment Directive (WEEE) of the European Community, manufacturers of new electrical and electronic equipment in Europe are obliged to take back and recover old electrical and electronic appliances. Plastics containing bromated flame retardants have to be segregated, which can entail considerable additional costs. The take-back and dismantling obligation has been in force in Germany and Denmark since the end of March or beginning of April 2006. In Austria, Belgium and Ireland, this stipulation has existed for quite some time while in France, Spain, Italy and Great Britain, it will only take effect at a later point in time.