Polyolefin Composition for Vehicle NVH Thermoforming

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Solution Overview

Problem

Conventional sound-deadening composites for automotive applications lack sufficient melt strength and elasticity, making them inadequate for forming complex articles through thermoforming processes, especially in applications requiring deep draws.

Innovation Solution

A polyolefin composition comprising a physical mixture of 97-90 parts by weight of a filled polyolefin composition, including linear or substantially linear ethylene polymers and 60-95 weight percent filler, combined with 3-10 parts by weight of functionalized polyethylene, which is extruded without prior melt blending to achieve a balance of melt strength and elongation for effective thermoforming.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional ethylene vinyl acetate based compositions are used, then adequate modulus and balanced properties are achieved, but sufficient elasticity for forming complex articles is lacking

Engineering Contradiction:
ImprovemodulusVSAvoidelasticity for forming
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The patent combines ethylene vinyl acetate polymer (providing modulus and balanced properties) with elastomeric polymer (providing elasticity) in a composite composition. This merging of two different polymer systems allows the composition to simultaneously achieve adequate stiffness for structural integrity and sufficient elasticity for forming complex articles through thermoforming processes

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention uses a composite material system consisting of ethylene vinyl acetate polymer combined with elastomeric polymer, filler, and optional plasticizer. This composite approach allows synergistic combination of properties: the ethylene vinyl acetate provides modulus and dimensional stability while the elastomeric component provides the necessary elasticity and flexibility for deep draw forming

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If conventional ethylene-alpha olefin based compositions with adequate elasticity are used, then formability is improved, but sufficient melt strength for thermoforming is lacking

Engineering Contradiction:
ImproveformabilityVSAvoidmelt strength
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The patent merges ethylene vinyl acetate polymer (providing melt strength) with elastomeric polymer (providing elasticity and formability). The ethylene vinyl acetate component maintains high melt strength necessary for thermoforming processes, while the elastomeric component contributes sufficient elasticity to enable forming of complex articles with deep draws

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention optimizes the composition parameters including the ratio of ethylene vinyl acetate to elastomeric polymer, filler content (60-90 parts per 100 parts polymer), and optional plasticizer content to achieve the desired balance between melt strength and elasticity. By carefully controlling these parameters, the composition attains both sufficient melt strength for thermoforming and adequate elasticity for complex article formation

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If filled thermoplastic compositions are used to achieve density and cost-effectiveness, then sound-deadening properties are improved, but melt strength and elasticity balance is compromised

Engineering Contradiction:
ImprovedensityVSAvoidmelt strength and elasticity balance
Core Design Contradiction:
Quantity of substanceVSStrength

Solution Approach 1:

The patent employs a composite material system where filled thermoplastic composition (providing density and cost-effectiveness) is combined with elastomeric polymer (providing elasticity). The filler content is optimized at 60-90 parts per 100 parts polymer to achieve adequate density for sound-deadening applications while the elastomeric component compensates for the stiffness introduced by filler, maintaining sufficient elasticity and melt strength balance for thermoforming

Inventive Principle:
Principle #40Composite materials

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 composition demonstrates excellent sound-deadening properties and is capable of deep draws during thermoforming, providing a flexible and formable solution for automotive applications such as carpet underlayment and insulation.

Implementation Method 1

a polyolefin composition comprising a filled polyolefin composition (A) comprising one or more elastomeric component (1) and one or more filler (2) and a functionalized polyethylene (B)

Methodology Applied
Scientific EffectPolymer chain entanglement:

Implementation Method 2

capable of deep draws while providing excellent sound-deadening properties. The composition of the present invention is well suited for sheet extrusion and subsequent use in a thermoforming process

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP3071644B1Improved polyolefin composition for vehicle noise vibration and harshness applications
Publication Date: 2018.07.18 DOW GLOBAL TECHNOLOGIES LLC
  • EP3071644B1 patent drawingFigure 1
  • EP3071644B1 patent drawingFigure 2

AI summary

The present invention relates to polyolefin compositions useful as sound-deadening sheeting for formed vehicle applications. Said polyolefin composition comprises a physical mixture of a filled polyolefin and a functionalized polyethylene wherein the filled polyolefin comprises an elastomer, preferably one or more linear ethylene polymer and/or substantially linear polymer and a filler, preferably calcium carbonate. Said composition demonstrates a good balance of melt strength and elongation such that it is particularly suitable for sheet extrusion and thermoforming articles therefrom.