Vehicle Outer Trim Film Stack for Partial Translucency

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Solution Overview

Problem

Existing methods for manufacturing vehicle exterior cladding components lack an efficient and versatile process for creating partially translucent exterior trim parts with integrated decorative elements and functional features.

Innovation Solution

A method involving a film stack composed of a colored film with perforations and a design film, bonded with an adhesion promoter, is injected into a mold to form a base body using transparent plastic, with a sealing layer applied to enhance translucency and integrate functional elements like heating wires or LEDs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If existing manufacturing processes are used for exterior trim parts, then production is straightforward, but partial translucency and integration of functional elements cannot be achieved

Engineering Contradiction:
Improvepartial translucency and functional element integrationVSAvoidmanufacturing process complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple functions (translucency, decoration, adhesion, and functional element integration) into a single multi-layer film stack structure. The film stack integrates a carrier film, adhesion promoter layer, decorative layer, and color-imparting layer, allowing all these functions to be achieved through one component rather than separate manufacturing steps.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The film stack is divided into distinct functional layers, each serving a specific purpose. The carrier film provides structural support and translucency, the adhesion promoter layer ensures bonding, the decorative layer provides aesthetic appearance, and the color-imparting layer enables selective light transmission. This segmentation allows independent optimization of each layer's properties.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If a multi-layer film stack with perforations is used, then partial translucency and functional element integration are enabled, but manufacturing precision requirements increase

Engineering Contradiction:
Improvefunctional element integrationVSAvoidperforation and layer alignment precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The film stack is pre-assembled with all layers and perforations created before insertion into the injection molding tool. The perforations are punched through the carrier film in advance, and the layers are pre-aligned and bonded together. This preliminary preparation ensures precise alignment and reduces the complexity of the injection molding process.

Inventive Principle:
Principle #10Preliminary action

3Strength

If injection molding is used to bond the film stack, then strong adhesion is achieved, but control over which areas are pressed into perforations becomes challenging

Engineering Contradiction:
Improveadhesion strengthVSAvoidcontrolled pressing into perforations
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The injection molding process is designed to apply pressure selectively to specific areas of the film stack. The mold cavity geometry and injection parameters are controlled so that only certain regions of the decorative layer and adhesion promoter layer are pressed into the perforations, while other areas remain unaffected. This allows localized adhesion control.

Inventive Principle:
Principle #3Local quality

4Reliability

If a sealing layer is applied to seal the colored film and pressed areas, then protection and encapsulation are improved, but manufacturing steps and time increase

Engineering Contradiction:
Improvesealing and protectionVSAvoidmanufacturing cycle time
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The sealing layer application is combined with the injection molding process. The sealing layer is applied in the same molding cycle as the base body formation, eliminating the need for a separate sealing step. This integration maintains reliable sealing while improving manufacturing efficiency.

Inventive Principle:
Principle #5Merging (Combining)

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

Enables the production of partially translucent exterior trim parts with integrated decorative and functional features, offering design flexibility and improved adhesion through material bonding and sealing, suitable for various vehicle components.

Implementation Method 1

injecting a plasticized plastic material forming the base body into the cavity, wherein the plastic material consists of a plastic material that is transparent or translucent to visible light, wherein the plasticized plastic material is injected in such a way that it back-injects the film stack and thereby bonds with the film stack

Methodology Applied
Scientific EffectInjection molding:

Implementation Method 2

The adhesion promoter of the adhesion promoter layer is preferably intended to improve or enable the adhesion between polypropylene and polyurethane

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 3

Introducing a plurality of perforations into the color film, wherein the perforations completely penetrate the carrier film and the color layer to thereby enable partial translucency of the color film

Methodology Applied
Scientific EffectLight transmission: Light

Data Source

PatentEP4578622B1Method for producing a partially translucent outer trim part for a vehicle
Publication Date: 2026.04.29 RESRG AUTOMOTIVE SE & CO KG
  • EP4578622B1 patent drawingFigure 1~2
  • EP4578622B1 patent drawingFigure 3
  • EP4578622B1 patent drawingFigure 4

AI summary

The invention relates to a method for producing a partially translucent exterior trim part for a vehicle, wherein the exterior trim part has a base body (1), comprising the following steps: providing a color film (2) which has at least one carrier film (2a) made of a plastic material that is transparent or translucent to visible light and an opaque and color-imparting layer (2b) arranged on the carrier film (2a), providing a design film (3) which has at least one carrier film (3a) made of a plastic material that is transparent or translucent to visible light, a transparent or translucent adhesion promoter layer (3b) and a transparent or translucent decorative layer (3c) arranged between the carrier film (3a) and the adhesion promoter layer (3b), introducing a plurality of perforations (4) into the color film (2),wherein the perforations completely penetrate the carrier film (2a) and the color layer (2b) to thereby enable partial translucency of the color film (2), forming a film stack (5) from the color film (2) and the design film (3), wherein the adhesion promoter layer (3b) of the design film (3) lies against the side of the carrier film (2a) of the color film (2) facing away from the color-imparting layer (2b), inserting the film stack (5) into an injection molding tool having at least two mold halves (6, 7) which, in the closed state, form a cavity (8) defining the base body (1) between them, wherein the color-imparting layer (2b) of the color film (2) of the film stack (2) lies against the inner wall of one of the mold halves (6) or is opposite the inner wall of one of the mold halves (6), injecting a plasticized plastic material forming the base body (1) into the cavity (8),wherein the plastic material consists of a plastic material that is transparent or translucent to visible light, wherein the plasticized plastic material is injected in such a way that it back-injects the film stack (5) and thereby bonds with the film stack (5), wherein partial regions (9) of the decorative layer (3c) and the adhesion promoter layer (3b) arranged above the decorative layer (3c) are pressed into the perforations (4) of the colored film (2) by the injection pressure and/or the after-pressure of the plastic material forming the base body (1), applying a sealing layer (10) that seals the colored film (2) and the partial regions (9).