Bitumen-Plastic Foam Sandwich Panel for Lightweight Noise Deadening
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Solution Overview
Problem
In motor vehicles and household appliances, there is a need for improved soundproofing and thermal insulation while minimizing weight, as existing sound-damping sandwich panels often compromise on noise-deadening effectiveness and weight.
Innovation Solution
A sound-damping sandwich panel with a bitumen-plastic foam layer of specific density, modulus of elasticity, and composition, combined with a stiffening layer and adhesive connections, is designed to enhance noise-deadening and thermal insulation properties while maintaining a low weight, with the bitumen-plastic foam layer having cavities that improve vibration transmission and thermal insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional sound-damping sandwich panels are used, then noise-deadening effect is achieved, but weight increases
Solution Approach 1:
The patent uses a composite sandwich panel structure consisting of a bitumen-plastic foam layer combined with a stiffening layer (aluminum, steel, or fiber-reinforced plastic). This composite construction achieves effective noise deadening while reducing weight compared to conventional single-material panels, as the foam layer provides acoustic damping and the thin stiffening layer provides structural integrity without excessive weight.
Solution Approach 2:
The bitumen-plastic foam layer is a porous material with cellular structure that effectively absorbs and dampens vibrations and sound waves. The foam structure provides high noise-deadening performance per unit weight, resolving the contradiction between achieving good acoustic properties and minimizing weight.
2Weight of moving object
If bitumen-plastic foam layer with optimized density is used, then weight is reduced, but noise-deadening effectiveness may be compromised
Solution Approach 1:
The patent specifies optimizing the density of the bitumen-plastic foam layer to the range of 0.20-0.40 g/cm³, with a preferred value of 0.30 g/cm³. This parameter optimization ensures the foam provides sufficient noise deadening while maintaining low weight. The stiffening layer thickness is also optimized (0.05-0.5 mm) to work synergistically with the foam layer, ensuring structural integrity without excessive weight.
3Weight of moving object
If sandwich panel thickness is reduced, then weight is decreased, but acoustic performance may be impaired
Solution Approach 1:
The composite sandwich structure allows for thin overall dimensions (1-5 mm, preferably 2-4 mm) while maintaining acoustic performance. The combination of bitumen-plastic foam with a stiffening layer creates a lightweight composite that achieves effective noise deadening at reduced thickness compared to conventional single-layer panels, resolving the contradiction between thin dimensions and acoustic effectiveness.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution achieves a significant noise-deadening effect and thermal insulation with reduced weight, offering up to 50% less weight than conventional panels with similar acoustic performance, and can be adapted for specific applications by optimizing material compositions and dimensions.
Implementation Method 1
The second layer has a modulus of elasticity in the range from 2000 to 4000 N/mm2, preferably in the range from 2500 to 3500 N/mm2 and in particular about 3000 N/mm2. This improves the transmission of vibrations or kinetic energy from the component to layers further out.
Implementation Method 2
The first layer (20) and the second layer (30) are connected to one another directly or by means of an intervening first adhesive layer (50)... The second layer (30) is provided according to the invention with a further, second adhesive layer (52)... kinetic energy can be converted into heat in the two layers of adhesive due to friction.
Implementation Method 3
The second layer has hollow spheres, in particular hollow spheres filled with air, which significantly improves the deadening effect, but at the same time the thermal insulation properties can also be improved
Data Source
Figure 1~2
Figure 3
AI summary
The present invention relates to a sound-absorbing sandwich board (10), comprising: a first layer (20) for sound absorption and/or sound-proofing and a second layer (30) for sound-deadening and/or thermal insulation, which is rigidly connected at its first main face (32) to the first layer (20) and is intended to be connected at its second main face (38) to a component (8) to be improved acoustically. The invention is characterised in that the second layer (30) is a bitumen-plastic foam layer with a density of 0.2 to 0.9 kg/dm3, preferably from 0.25 to 0.5 kg/dm3 and in particular of 0.3 kg/dm3. The invention also relates to a layer for sound absorption and/or for sound-proofing and a sound-deadening layer for the sandwich board (10) and a method for attaching a sound-absorbing sandwich board (10) to a component to be improved acoustically.