Acoustic properties of Dash Insulation Pad with light-weight heavy layer filled with TEMs

At present, fuel efficiency improvement technologies for example light-weight, engine efficiency improvement, design modification, and eco-friendly car are being proceeded due to the tightened international regulations. But there are disadvantages due to the limited technology improvement and materials & products. The research on light-weight of material is good for improvement of engine efficiency is being proceeded. There are representative light-weight methods for example structures, processes and materials of which is the most effective one is material. TEMs(Thermally expandable microcapsules) is one of foaming technology and composited of core-shell structure whose have uniform to increase mechanical properties. In this study, we applied TEMs for lightweight development on the generation TPE sheet of layers of Dash Insulation Pad as automotive interior parts for reducing engine noise. We investigated specific gravity, thickness, mechanical properties, acoustic properties and pore size with 1, 3, 5 wt% contents of TEMs. The specific gravity was reduced 14%, and thickness was increased 13% compare to standard TPE. The tensile strength showed 1.1 MPa to 1.0 MPa with TEMs. TEMs showed 10 times expansion ratio of TEMs by optical microscope. The acoustic properties were measured by Impeadance tube, APAMAT- and PBNR(power based noise reduction).