Acoustic and thermal shield for a motor vehicle

An acoustic and thermal shield for a motor vehicle, the shield comprising:

• a thermo-compressed porous three-dimensional shell based on glass fibers, the fibers being joined together by a binding agent,
• a foam-based inner spring layer made of elastically compressible polyurethane,
• the shield further comprising:
• spring layer produced by reaction injection molding, the layer overmolding the shell,
• the shell having a porosity arranged to enable the foam to penetrate a fraction of the thickness of the shell, to create a leaktight skin, such that the shield:
• is acoustically insulating according to a mass-spring principle, the shield additionally having acoustic absorption properties conferred by the fraction of thickness of the shell not penetrated by the foam and remaining porous,
• has the rigidity thereof increased by the reinforcement by the fibers coated by the foam,
• the shield having:
• the binding agent based on polypropylene, and
• the shell comprises between 45 and 55% by weight of glass fibers.