Overlapping LWRT and GMT Thermoplastic Underbody Panels

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Solution Overview

Problem

Current plastic components for motor vehicles made from thermoplastic materials face limitations in achieving complex geometries and strength, particularly in underbody panels, due to mechanical weak points from separate manufacturing processes and geometric restrictions.

Innovation Solution

A method and design where a GMT component with complex geometry is overlapped and consolidated with a LWRT component, eliminating air gaps and wrinkles by increasing wall thickness and using a sawtooth-like or meandering design, allowing for direct one-shot production without additional tools or welding systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If complex geometries are implemented using separate injection-molded inserts welded into the LWRT component, then the desired geometric complexity is achieved, but mechanical weak points are created and manufacturing complexity increases

Engineering Contradiction:
Improvegeometric complexityVSAvoidmechanical strength
Core Design Contradiction:
ShapeVSReliability

Solution Approach 1:

The patent merges the LWRT component and GMT component into a single integrated structure through overlapping and consolidation. The GMT component is pressed overlapping onto the LWRT component in a one-shot process, eliminating separate welding operations and creating a unified structure without mechanical weak points at connection interfaces.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent uses composite materials by combining LWRT (low weight reinforced thermoplastics) and GMT (glass mat reinforced thermoplastics) in an overlapping configuration. This composite construction allows the GMT component to provide structural strength while the LWRT component provides the base structure, achieving both geometric complexity and mechanical strength.

Inventive Principle:
Principle #40Composite materials

2Shape

If complex geometries are implemented using separate injection-molded inserts and welding, then the desired geometric complexity is achieved, but the number of manufacturing processes increases

Engineering Contradiction:
Improvegeometric complexityVSAvoidmanufacturing process complexity
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The patent combines multiple manufacturing operations into a single one-shot process. The LWRT component is formed first, then the heated GMT component is pressed overlapping onto it in the same manufacturing cycle, eliminating the need for separate injection molding and welding operations.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The LWRT component is pre-formed and consolidated before the GMT component is pressed onto it. This preliminary action allows the base structure to be prepared in advance, enabling the subsequent GMT component to be integrated directly without requiring separate manufacturing steps.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the LWRT component is pressed without consolidation, then production speed is maintained, but air gaps and wrinkles appear in the component

Engineering Contradiction:
Improveproduction speedVSAvoidsurface quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The LWRT component is pre-consolidated in the area where the GMT component will be pressed overlapping onto it. This preliminary consolidation action removes air gaps and prepares the surface in advance, ensuring high manufacturing precision when the GMT component is integrated, without requiring additional time during the main pressing operation.

Inventive Principle:
Principle #10Preliminary action

4Quantity of substance

If the GMT component flows over the dividing line during production, then material distribution is achieved, but the LWRT component wrinkles under the flow pressure

Engineering Contradiction:
Improvematerial distributionVSAvoidsurface quality
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The LWRT component is pre-consolidated in the overlap area before the GMT component is pressed onto it. This preliminary action creates a dense, wrinkle-resistant surface that can withstand the flow pressure of the GMT material during pressing, preventing surface defects while allowing proper material distribution.

Inventive Principle:
Principle #10Preliminary action

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 approach enhances strength, rigidity, and reduces production costs by integrating complex geometries like air ducts directly into the component, eliminating mechanical weak points and simplifying the manufacturing process.

Implementation Method 1

after heating above the melting temperature of the thermoplastic matrix

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

heating above the melting temperature of the thermoplastic matrix

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 3

the heated LWRT blank is formed and consolidated in a partial area, the slide is also advanced with the mold closed and the heated GMT blank is welded to the heated LWRT blank

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 4

the heated GMT blank is welded to the heated LWRT blank in its consolidated area

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP2468481B1Construction element made from plastic for a motor vehicle and method for producing such a construction element
Publication Date: 2015.01.14 HBW GUBESCH THERMOFORMING GMBH
  • EP2468481B1 patent drawingFigure 1~2
  • EP2468481B1 patent drawingFigure 3~4
  • EP2468481B1 patent drawingFigure 5a~5d

AI summary

The element (1) has a low weight reinforced thermoplastic (LWRT) blank (2) i.e. plate-like component, made of LWRT plastic. A glass mat reinforced thermoplastic (GMT) blank (3) is made of GMT plastic. The blanks are overlappingly arranged. The LWRT blank is designed consolidated in an overlapping region. The GMT blank includes projections in the overlapping region. The projections are formed by a sawtooth like or meander shaped design of the GMT blank in the overlapping region. The LWRT blank forms an underbody lining. The GMT blank forms an airduct i.e. braking air duct. An independent claim is also included for a method for manufacturing a construction element.