Lofty Fibrous Trim Part Shrinkage Reduction

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Solution Overview

Problem

Moulded fibrous vehicle trim parts experience thickness shrinkage during the moulding process, leading to reduced noise-absorbing properties due to the softening and collapse of the fibrous structure, especially when using recycled polyester materials, which have lower softening temperatures and are less predictable.

Innovation Solution

Incorporating polysiloxane as a shrinkage-reducing additive in the sheath polymer of thermoplastic bicomponent filaments or staple fibers, allowing the fibrous structure to maintain its loftiness and open spaces, even when heated above the softening point, thereby reducing thickness shrinkage and preserving noise-absorbing properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If fibrous material is heated during moulding to consolidate the structure, then the material bonds form and structural integrity improves, but the fibrous structure collapses and thickness shrinkage increases

Engineering Contradiction:

Improvestructural integrityVSAvoidthickness

Core Design Contradiction:

StrengthVSLength of stationary object

Solution Approach 1:

The patent changes the chemical composition parameters of the binder polymer by incorporating shrinkage-reducing additives (silane-modified polymers, polysiloxanes, or crystalline nucleating agents) to modify the thermal behavior and shrinkage characteristics of the material during heating, allowing consolidation without excessive thickness loss

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system combining fibrous reinforcement (polyester, polypropylene, or natural fibers) with a specially formulated binder polymer containing shrinkage-reducing additives, where the binder provides both bonding and shrinkage control functions while preserving the lofted structure

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If recycled polyester is used to reduce material costs and improve sustainability, then environmental performance improves, but softening temperature decreases and thickness shrinkage increases

Engineering Contradiction:

Improveenvironmental impactVSAvoidthickness

Core Design Contradiction:

Object-affected harmful factorsVSLength of stationary object

Solution Approach 1:

The patent adjusts the chemical composition parameters of the binder polymer by adding shrinkage-reducing additives that compensate for the lower softening temperature of recycled polyester, allowing the material to maintain dimensional stability during moulding despite using recycled content

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the potential harm of recycled polyester's lower thermal stability into a benefit by using shrinkage-reducing additives that actually improve dimensional control, allowing the use of sustainable recycled materials without sacrificing part quality

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Strength

If the fibrous structure is densely packed to increase material density, then structural strength improves, but noise absorbing properties decrease

Engineering Contradiction:

Improvestructural strengthVSAvoidnoise absorption

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent optimizes the binder polymer composition with shrinkage-reducing additives that enable adequate bonding at lower binder concentrations, allowing the fibrous structure to remain loosely packed for noise absorption while still achieving sufficient structural strength through improved binder efficiency

Inventive Principle:

Principle #35Parameter changes

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 use of polysiloxane additives in the binder polymer significantly reduces thickness shrinkage, enabling the production of moulded parts with enhanced design freedom and acoustic performance, while allowing the use of both virgin and recycled polyester sources, maintaining similar noise-absorbing properties at comparable densities.

Implementation Method 1

the fibrous layer is consolidated by heating thereby melting the sheath polymer forming binding points between the filaments or staple fibers

Methodology Applied

Scientific EffectMelting: Melting

Implementation Method 2

the sheath of the bicomponent filament or staple fibre comprises at least a shrinkage reducing additive being a polysiloxane or polydimethylsiloxane

Methodology Applied

Scientific EffectShrinkage reduction:

Implementation Method 3

Although the material may be heated at least above the softening point of the core material of the bicomponent filaments or staple fibers

Methodology Applied

Scientific EffectSoftening:

Data Source

PatentUS11396159B2Lofty fibrous trim part

Publication Date: 2022.07.26 AUTONEUM MANAGEMENT AG

AI summary

Trim part for a vehicle, comprising at least a fibrous layer comprising of thermoplastic bicomponent filaments or staple fibers, consisting of a first polymer forming the sheath of the bicomponent filament or staple fiber and a second polymer forming the core of the bicomponent filament or staple fiber and whereby the fibrous layer is consolidated by heating thereby melting the sheath polymer forming binding points between the filaments or staple fibers, characterized in that at least the sheath of the bicomponent filament or staple fiber comprises a shrinkage reducing additive being at least a polysiloxane, preferably a polydimethylsiloxane.