MASS-SPRING ACOUSTIC INSULATION

摘要

The invention concerns an acoustic insulation, particularly designed for use in a motor vehicle. The acoustic insulation comprises a heavy mass and an acoustic spring layer. Said spring-layer comprises crimped fibers ranging between 3 decitex and 7 decitex and a binder for maintaining together said crimped fibers. The invention is characterized in that the acoustic insulation exhibits the following features: the spring-layer further comprises microfibers ranging between 0.1 decitex and 1 decitex; the weight of the microfibers in the spring-layer ranges between 25 % and 400 % of the weight of the crimped fibers; and the weight of the microfibers and the weight of the crimped fibers represent together at least 35 wt. % of the spring-layer.