A key theme at the recent Fakuma exhibition in Friedrichshafen, Germany, was metal-to-plastics replacement. One such development reported previously by PlasticsToday was the use of a heat-resistant polyamide (PA) in its first commercial application.
 Goodbye to aluminum (left in photo) as high-heat PA provides heat shielding and air flow turbulence effects |
The resin in question is UltramidEndure from BASF (Ludwigshafen, Germany). German processor Montaplast (Morsbach, Germany) is using the PA material Ultramid Endure D3G7 for a heat shield in the charge-air manifold used on the 4 cylinder diesel-powered automobile engine from Daimler.
In the air intake region of the charge-air manifold, which features integral exhaust gas recirculation, fresh air and hot exhaust gases are brought together. This is where high mixing temperatures and strong turbulence are encountered. Until now, an aluminum shield provided protection for the wall and a built-in sensor. Now, a heat-resistant plastic insert fulfills this function. The superior heat aging resistance of Ultramid Endure comes into play here: The material can easily withstand a continuous service temperature of 220°C and peak temperature of up to 240°C. Stabilization technology that creates a protective surface layer on the plastic is responsible for the high heat resistance of this polyamide specialty.
Two additional properties of the plastic distinguish the new heat shield from its metal predecessor: First, the plastic functions as a thermal insulator. Additionally, it was possible to incorporate openings in the Ultramid Endure heat shield to generate a specific turbulence in the charge air. Moreover, the weight of the plastic part is only half of the previously used aluminum part.
The engine compartment is becoming increasingly compact and thus hotter says BASF. Simultaneously, the vehicle should become lighter by substituting plastic for metal. Because of their high system costs, however, BASF says that high-performance plastics are generally ruled out. The new polyamide UltramidEndure, however, combines its exceptionally high heat aging resistance with the superior processability of PA 66 - the characteristic that is the determining factor when it comes to system costs. The material is thus said to be an ideal alternative for applications all around the charge-air system in modern turbocharged engines.-[email protected]
