Melt-Bonded PET Nonwoven Laminate for Stone-Chip Durability
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Solution Overview
Problem
Current nonwoven composites and moulded articles for automotive applications lack sufficient mechanical stability, durability, and resistance to stone-chipping, while also facing challenges in maintaining properties over long-term use and meeting stringent industry standards for structural parts like underbody shields and wheel arch liners.
Innovation Solution
A nonwoven laminate comprising a spunbond layer of PET and copolyester fibers, a needled staple fiber layer with monocomponent and multicomponent PET staple fibers, and optionally an additional spunbond layer with higher copolyester content, all melt-bonded together to enhance homogeneity, dimensional stability, and peel strength, reducing the elephant skin effect and enabling high heat resistance and recyclability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If nonwoven composites are used for automotive structural parts, then mechanical stability and durability are improved, but resistance against stone-chipping deteriorates
Solution Approach 1:
The patent uses a composite nonwoven laminate structure combining three different nonwoven layers (spunbond, needled, and hydrophobic treatment layers) to achieve both mechanical stability and stone-chipping resistance. Each layer contributes specific properties that complement each other, creating a synergistic effect that resolves the contradiction between strength and chip resistance.
Solution Approach 2:
The patent applies local quality by treating only the outer surface layer with hydrophobic additives and specific fiber orientation to enhance stone-chipping resistance, while maintaining the internal layers optimized for mechanical strength and acoustic properties. This localized treatment allows differentiation of functions across different regions of the material.
2Object-generated harmful factors
If nonwoven laminates are used for automotive parts, then acoustic shielding is improved, but mechanical durability deteriorates
Solution Approach 1:
The patent combines multiple nonwoven layers with different fiber types, densities, and treatments to simultaneously achieve acoustic shielding and mechanical durability. The needled layer provides acoustic absorption while the hydrophobically treated outer layer provides durability, creating a composite structure where each layer serves multiple functions.
Solution Approach 2:
The patent modifies physical and chemical parameters of the nonwoven layers, including fiber diameter distribution, basis weight, needling intensity, and hydrophobic treatment concentration, to optimize both acoustic performance and mechanical durability. These parameter adjustments allow tuning of the material properties to meet conflicting requirements.
3Strength
If hydrophobic additives are incorporated to improve stone-chipping resistance, then mechanical stability is improved, but recyclability deteriorates
Solution Approach 1:
The patent carefully controls the concentration and type of hydrophobic additives to achieve sufficient stone-chipping resistance while maintaining recyclability. By optimizing the additive dosage and selecting compatible materials, the patent finds a balance point where performance requirements are met without compromising the ability to recycle the material through standard processes.
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 provides nonwoven laminates and moulded articles with improved mechanical stability, acoustic properties, and resistance to stone-chipping, suitable for long-term use in automotive structural parts, while being cost-effective and recyclable, with reduced heat shrinkage and elephant skin formation.
Implementation Method 1
The layers are melt-bonded to each other
Data Source
AI summary
Subject of the invention is a nonwoven laminate, consisting of, in order (A) to (C): - a spunbond nonwoven layer (A) comprising fibres, which comprise polyethylene terephthalate (PET) and copolyester; - an optional spunbond nonwoven layer (B) comprising fibres, which comprise polyethylene terephthalate (PET) and copolyester, the nonwoven layer (B) having a higher copolyester content than nonwoven layer (A); - a needled staple fibre nonwoven layer (C), comprising: ∘ monocomponent polyethylene terephthalate (PET) staple fibres (c1), and ∘ multicomponent staple fibres (c2), which comprise at least a polyethylene terephthalate (PET) component and a copolyester component. wherein all layers are melt-bonded to each other. The invention relates also to moulded articles comprising the nonwoven laminate, to uses thereof and to production methods.