FKM & AEM Hose Constructions for Charged Air Cooler Applications

High temperature AEM (HT-AEM) polymers recently introduced to the market are being successfully used in hot side hoses capable of operating up to 180°C.  Applications with temperatures above 180°C have traditionally required constructions containing an FKM inner layer and a VMQ cover.  However the cost of these constructions, and the adhesion between the FKM and VMQ layers, especially after heat aging, are ongoing concerns. 

 An alternative construction capable of temperature up to 200°C, utilizes an FKM inner layer and an HT-AEM cover layer.  Such a construction provides advantages in adhesion and cost over FKM / VMQ hose. 

 A key consideration in the selection of an FKM / HT-AEM construction is the potential thermal gradient that can exist across a turbo hose cross section.  In many applications the inner layer is exposed to much higher temperatures than the outer cover.   Additionally, a thermally stable inner layer such as FKM can provide a protective barrier to oxidation of the adjacent HT-AEM layer.  This paper will explore the properties and performance of  FKM / HT-AEM hose constructions, and data will be presented showing the anaerobic aging characteristics of HT-AEM at 200°C and the retention of adhesion to FKM after exposure to high temperature.