Composite Preform Zonal Stitching for Corner Wrinkle Prevention

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for fabricating composite components with complex shapes, such as corners, often result in wrinkles or weak spots due to the difficulty in evenly distributing resin and reinforcing fibers, leading to poor quality and the need for manual strengthening.

Innovation Solution

A method involving stitching continuous reinforcing fibers in specific zones on a backing substrate, with reduced fiber and stitch densities in zones near complex surfaces, to prevent wrinkles and resin blocking during resin transfer molding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If uniform fiber and stitch density is used throughout the preform, then manufacturing simplicity is maintained, but wrinkles and weak spots occur in corner regions during molding

Engineering Contradiction:

Improvequality of composite componentVSAvoidcomplexity of fiber placement pattern

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies local quality by implementing different fiber densities and stitch densities in different zones of the preform. Specifically, corner zones have reduced fiber density and reduced stitch density compared to non-corner zones, allowing each region to have properties optimized for its specific geometric and functional requirements. This resolves the contradiction by improving manufacturing precision through localized optimization while managing complexity through a systematic zonal approach.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent segments the preform into multiple zones based on their geometric characteristics and molding behavior. Corner zones are identified and separated from non-corner zones, allowing independent optimization of fiber and stitch densities in each segment. This segmentation enables the resolution of wrinkles in corners without compromising the overall structural integrity, thereby improving manufacturing precision while organizing complexity into manageable segments.

Inventive Principle:

Principle #1Segmentation

2Stability of the object's composition

If high stitch density is used to secure fibers, then fiber placement stability is improved, but resin flow blocking occurs during resin transfer molding

Engineering Contradiction:

Improvestability of fiber placementVSAvoidthroughput of resin transfer molding

Core Design Contradiction:

Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent applies local quality by implementing variable stitch density across different zones of the preform. Corner zones have reduced stitch density compared to non-corner zones, allowing resin to flow more freely through corner regions during molding. This resolves the contradiction by maintaining sufficient fiber stability in high-stitch-density areas while enabling adequate resin flow in reduced-stitch-density areas, thereby improving both composition stability and molding productivity.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the stitch density parameter spatially across the preform, creating a gradient from high stitch density in non-corner zones to low stitch density in corner zones. This parameter variation allows the system to maintain fiber placement stability where needed while removing resin flow restrictions where corners require greater permeability, thus resolving the contradiction between stability and productivity.

Inventive Principle:

Principle #35Parameter changes

3Strength

If high fiber density is used to strengthen corners, then structural strength is improved, but resin impregnation becomes difficult leading to dry spots

Engineering Contradiction:

Improvestrength of corner regionsVSAvoiduniformity of resin distribution

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The patent applies local quality by implementing reduced fiber density in corner zones compared to non-corner zones. This allows resin to penetrate and impregnate corner regions more effectively, preventing dry spots and ensuring uniform resin distribution throughout the composite component. The fiber density is optimized locally to balance structural strength requirements with resin flow requirements, resolving the contradiction between strength and manufacturing precision.

Inventive Principle:

Principle #3Local quality

4Reliability

If manual strengthening is performed to fix wrinkles and weak spots, then component reliability is improved, but manufacturing time and cost increase

Engineering Contradiction:

Improvereliability of composite componentVSAvoidmanufacturing cycle time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-configuring the fiber placement pattern with appropriate density variations in corner zones before the molding process begins. This preliminary optimization of fiber and stitch density prevents wrinkles and weak spots from forming during molding, eliminating the need for subsequent manual strengthening operations. The reliability of the component is ensured through proactive design rather than reactive repair, thereby reducing manufacturing cycle time and eliminating the loss of time associated with manual interventions.

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 reduces wrinkling and resin blocking in composite components, eliminating the need for manual strengthening and enhancing the quality and throughput of the manufacturing process.

Implementation Method 1

sensing a position of the preform in a molding tool using a position sensor configured to detect at least one of the T third zones

Methodology Applied

Scientific EffectPosition sensing:

Implementation Method 2

using heating pads to heat regions of a molding tool near the N first zones

Methodology Applied

Scientific EffectThermal heating: Heating

Implementation Method 3

shaping the preform using the molding tool; and resin transfer molding the preform in the molding tool

Methodology Applied

Scientific EffectMechanical compression: Compression

Implementation Method 4

resin transfer molding the preform in the molding tool to create the composite panel

Methodology Applied

Scientific EffectResin impregnation: Diffusion

Data Source

PatentUS12275204B2Composite components and multi-zone fiber preforms for composite components

Publication Date: 2025.04.15 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A method for fabricating a composite panel comprising stitching a plurality of first continuous reinforcing fibers in N first zones and M second zones of a backing substrate of a preform. The N first zones are arranged near C corners of the composite panel, where C is an integer. The plurality of first continuous reinforcing fibers in the N first zones is arranged radially relative to the C corners. At least one of a fiber density of the plurality of first continuous reinforcing fibers in the N first zones that is less than a fiber density of the plurality of first continuous reinforcing fibers in the M second zones, and a stitch density of the plurality of first continuous reinforcing fibers in the N first zones that is less than a stitch density of the plurality of first continuous reinforcing fibers in the M second zones.