Vandar® thermoplastic polyester alloy (PBT)
Available from Celanese Corporation
Drawing on the basic properties of PBT enables Vandar alloys to achieve high ductility and good stiffness with excellent chemical and thermal resistance. These alloys are easy to mold and retain their impact strength down to -30° C (-21° F) and are available in both unreinforced grades and as compounds with glass fiber and minerals.
All unreinforced Vandar products have high impact resistance while retaining strength and stiffness. One grade additionally has a V-0 rating in the UL 94 flammability test down to a thickness of 0.85 mm (0.033 in). A key to the value offered by Vandar it has high impact even well below freezing, yet retains sufficient stiffness to prevent creeping and sagging at much higher temperatures. This property is particularly important in applications like auto airbag covers, where ductile tearing is essential even in subfreezing deployment, but structural integrity must be maintained after baking under hot sun in a closed vehicle.
Glass-reinforced Vandar alloy grades provide added strength, stiffness and toughness over a wide temperature range, from -40° C to 130° C (-40° F to 261° F). A low warp mineral-filled grade is also available that can be painted directly.
Vandar alloys have been used in smaller parts like switches and connectors through brake and fuel line clips, power distribution boxes, wheel covers, headlamp bezels and air bag doors to large bulky parts such as bumper fascia and telephone line splice cases.