Composite Automotive Trim Part Textured Skin Process

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Solution Overview

Problem

Current overmolding processes for producing composite automotive trim parts are costly, require oversized tools, and result in long cycle times and imperfect quality, particularly for large and aesthetic pieces.

Innovation Solution

A method involving the application of an aqueous thermoplastic dispersion derived from extrusion melt blending of thermoplastic polymer, dispersing agent, and water onto a rigid or foam substrate, followed by molding in a textured mold to create a composite part with a textured skin and substrate layer, using a compression molding machine or similar apparatus.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional overmolding processes are used to produce composite automotive trim parts, then the parts can be manufactured with multiple materials, but the process requires numerous costly tools, has long cycle times, and produces imperfect quality pieces

Engineering Contradiction:
Improvemanufacturing cost and tooling requirementsVSAvoidproduction rate and cycle time
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent combines multiple operations (spray application, drying, molding) into a single integrated process using one mold with multiple cavities. The mold receives sprayed dispersion in one cavity, transfers to another cavity for molding, eliminating the need for numerous separate tools and machines while maintaining multi-material composite production

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single mold performs multiple functions: it serves as both the application surface for the sprayed dispersion and the molding tool for forming the final part. The mold's multiple cavities allow simultaneous production of different sections, making one tool replace numerous specialized tools

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Area of stationary object

If traditional overmolding processes use oversized tools to accommodate large pieces, then large aesthetic parts can be produced, but the tools become very costly and require oversized machines

Engineering Contradiction:
Improvepart size capabilityVSAvoidtool cost and machine size
Core Design Contradiction:
Area of stationary objectVSEase of manufacture

Solution Approach 1:

The mold is divided into multiple cavities, each capable of receiving sprayed dispersion and forming different sections of the final part. This segmentation allows the production of large aesthetic parts by assembling multiple smallerformed sections within a single mold, avoiding the need for one oversized tool

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If movable blocks with hydraulic cylinders are used to achieve single-impression tooling, then both single-material and bi-material pieces can be obtained, but operating clearances are required and burrs appear on visible surfaces at high production rates

Engineering Contradiction:
Improvematerial type flexibilityVSAvoidsurface quality and burr formation
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent removes the movable blocks and hydraulic cylinders from the process entirely. Instead, the mold is stationary with multiple fixed cavities that receive sprayed dispersion and are filled by transfer, eliminating the mechanical complexity and clearance issues while maintaining the ability to produce both single-material and bi-material pieces

Inventive Principle:
Principle #2Taking out (Extraction)

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

This method enables the production of high-quality, aesthetically pleasing multi-material composite parts with a textured skin and substrate layer at high production rates, reducing costs and tooling requirements while improving finish and appearance.

Implementation Method 1

The process comprises the steps of spraying or casting an aqueous thermoplastic dispersion onto a rigid or foam substrate

Methodology Applied
Scientific EffectSpray: Spray

Implementation Method 2

C) heating the composite structure

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

E) closing the mold halves and contacting the composite structure; F) forming a rigid or foam substrate composite part

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 4

H) cooling the composite part

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 5

the aqueous thermoplastic dispersion is derived from the extrusion melt blending of a) a thermoplastic composition in the presence of b) at least one dispersing agent, and c) water

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Data Source

PatentEP3635042B1Process to make a composite automotive trim part
Publication Date: 2022.03.02 DOW GLOBAL TECHNOLOGIES LLC
  • EP3635042B1 patent drawingFigure 1

AI summary

The present invention relates to a method for producing a composite part comprising a textured skin and a rigid or foam substrate layer, in particular a composite automotive trim part. The method comprises the steps of spraying or casting an aqueous thermoplastic dispersion onto a rigid or foam substrate composite followed by forming the composite into a composite part comprising a textured skin and a rigid or foam substrate layer. Preferably, the dispersion is derived from the extrusion melt blending of thermoplastic polymer, a dispersing agent, and water.