Bayer MaterialScience AG has added four new grades to its range of fire-retardant polycarbonates (PC). Makrolon® 2467 and 6357 are non-reinforced, extremely flowable, transparent/translucent product grades, Makrolon® 6267 is a non-reinforced, easy-flowing, opaque material, and Makrolon® 9417 is a polycarbonate reinforced with ten percent glass fibers. ”By introducing these new grades, we are reacting to the increasing demand from the electrical, IT and domestic appliance industries for fire-retardant thermoplastics that can be processed into transparently or translucently pigmented components with complex, finely structured geometries,” explains Hans Franssen, an expert in technical product management for fire-retardant polycarbonates at Bayer MaterialScience. ”Our new materials are the material of choice especially when high heat resistance is also required.” Potential applications include housing components for television sets, monitors, notebooks, electrical devices, plugs, edge connectors, electrical distributors and fuse boxes. All the new PC grades are UV-stabilized and can also be used in outdoor applications.
”Developing the material was a tricky process because adding fire retardants to highly flowable thermoplastics often has a negative impact on other product properties. However, we succeeded in achieving a balanced property profile,” explains Franssen. Despite their flame retardance packages, grades such as Makrolon® 2467 and 6267 are as free-flowing as the standard injection molding type Makrolon® 2405, which is not flame-retardant.
The flame retardance packages of all the new PC grades are free of antimony, chlorine and bromine. They therefore comply with the two new EU directives on the disposal of plastics from electrical and electronic equipment, the WEEE (Waste Electrical and Electronic Equipment) and the RoHS (Restriction of the Use of Hazardous Substances in Electrical and Electronic Equipment). What is more, they fulfill the criteria of major ecolabels such as ”TCO 05” and the ”Blue Angel”. Thanks to their outstanding fire retardance, they also meet the requirements of domestic appliance standard IEC 60335-1, which was recently tightened. Their Glow Wire Flammability Index (GWFI) and Glow Wire Ignitability Temperature (GWIT) easily comply with and often greatly exceed the requirements of IEC 60695-2-12 and IEC 60695-2-13 respectively. Makrolon® 6267 and 9417 meet the UL 94 V (Underwriters Laboratories) fire standard and achieve an excellent V-0 classification at 1.5 mm wall thickness. In the UL 94-5V fire test, Makrolon® 9417 also achieves a 5VA classification at 3 mm wall thickness.