Filled Polyethylene Composition for Vehicle Acoustic Insulation
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Solution Overview
Problem
Current acoustic insulators in vehicles face challenges in achieving effective sound reduction while minimizing weight, as reducing the weight of the barrier layer compromises insulation performance, and existing thermoplastic compositions lack sufficient stiffness for shipping in stacked form.
Innovation Solution
A thermoplastic composition comprising a combination of two different ethylene polymers, inorganic filler particles, and a plasticizer, which provides the necessary stiffness and weight reduction without compromising sound-deadening performance, allowing the material to be shipped in stacked form.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the weight of the barrier layer is reduced, then fuel consumption is decreased and ecological requirements are met, but acoustic insulation performance is compromised
Solution Approach 1:
The patent employs composite materials by combining polyethylene polymer with inorganic fillers (such as barium sulfate, calcium carbonate, or glass beads) and plasticizers to create a filled thermoplastic composition. This composite approach allows the material to achieve the desired balance between reduced weight and maintained acoustic performance, as the inorganic fillers provide density and sound-blocking properties while the polymer matrix provides structural integrity and flexibility.
Solution Approach 2:
The patent applies parameter changes by carefully controlling the composition ratios of polymer, filler, and plasticizer, as well as adjusting processing parameters such as melt temperature and mixing conditions. By optimizing these parameters, the material achieves the target area weight (2.0-4.0 kg/m²) while maintaining the necessary stiffness (flexural modulus) and acoustic insulation properties through precise compositional tuning.
2Weight of moving object
If the thickness of the barrier layer is reduced to achieve weight reduction, then area weight decreases, but the material lacks sufficient stiffness for shipping in stacked form
Solution Approach 1:
The filled thermoplastic composition serves as a composite material where inorganic fillers (barium sulfate, calcium carbonate, glass beads) dispersed in the polyethylene matrix provide enhanced stiffness and dimensional stability. This composite structure enables thin layers (1-4 mm thickness) to maintain sufficient flexural modulus for stacked shipping while achieving the target area weight reduction, as the fillers contribute to rigidity without proportionally increasing weight.
Solution Approach 2:
The patent applies local quality by creating a non-uniform distribution of fillers and plasticizers within the polymer matrix. The filler particles are distributed throughout the material to provide localized stiffness enhancement, while plasticizer concentration is optimized to ensure adequate flexibility in specific regions. This localized optimization allows the thin barrier layer to maintain overall structural integrity and stiffness for shipping while achieving weight reduction.
3Ease of manufacture
If conventional thermoplastic compositions are used, then processing is simplified, but the material lacks sufficient stiffness for shipping and installation
Solution Approach 1:
The patent maintains ease of manufacture by utilizing standard thermoplastic processing parameters and conventional extrusion/forming equipment. The polyethylene-based composition with inorganic fillers and plasticizers can be processed using typical melt temperatures and processing speeds, preserving the simplicity of conventional manufacturing while achieving the enhanced stiffness required for stacked shipping through compositional optimization rather than process complexity.
Data Source
Figure 1
AI summary
Thermoplastic composition, comprising at least components (i) to (iii): (i) from 10 to 50 % by weight of a combination of at least one first ethylene polymer (A) and at least one second ethylene polymer (B), wherein (A) is selected such as to exhibit (a) a density of from 0.87 g/cm3 - 0.90 g/cm3 as determined according to ASTM D792; (β) a melt flow index of from 0.3 g/10 min - 5 g/10 min as determined according to ASTM D1238 (190 °C/2.16 kg); (γ) a flexural modulus of from 5 to 60 MPa measured according to ASTM D790; and wherein (B) is selected such as to exhibit (a) a density of from 0.90 g/cm3 - 0.92 g/cm3 as determined according to ASTM D792; (β) a melt flow index of from 0.3 g/10 min - 10 g/10 min as determined according to ASTM D1238 (190 °C/2.16 kg); (γ) a flexural modulus which is higher than that of (A); (ii) from 35 - 90 % by weight of inorganic particles as filler; (iii) from 0.05 - 20 % by weight of a liquid (at 23 °C) as a plasticizer for the at least one first ethylene polymer (A) and/or the at least one second ethylene polymer (B); the % by weight of components (i) to (iii) being based on the total weight of the composition.