Engine noise barrier

摘要: A co-injection molded air intake manifold shell comprises an inner and outer skin layer separated by a sound absorbing or insulation core. Each is composed of polyamide resin which, optionally, contains glass fiber reinforcement high specific gravity fillers such as barium sulfate tungsten. The insulating core density material having foam structure, resin. Skin layers are provided with plurality pockets to permit distribution localized lumped masses at predetermined locations tailored increase noise transmission losses. single non-uniform thickness also provided. the larger over preselected sources amplitude maximize attenuation for nominal thickness.