Fiber-Reinforced Composite Molding with Notched Prepreg Flaps

Solution Overview

Problem

Conventional methods for producing three-dimensional molded articles of fiber-reinforced composite materials with high curvature suffer from instability, unsatisfactory uniformity, and productivity issues due to wrinkle formation and fiber disorder during press-molding, especially when using prepregs with complex shapes.

Innovation Solution

A method involving the formation of notches or cutouts in prepregs to create partially separated flaps and residual portions, which are then arranged and overlapped to form a three-dimensional shape, preventing wrinkle formation and ensuring uniform fiber arrangement, using press dies with specific designs to maintain shape accuracy and prevent interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If manual laying of prepreg with notches or cutouts is used to form high curvature three-dimensional shapes, then wrinkle formation is prevented, but production stability and uniformity deteriorate

Engineering Contradiction:

Improvewrinkle formationVSAvoidproduction stability

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The overlapping portions of the prepreg sheets serve as self-positioning features that automatically guide the laying process. The notches or cutouts create flaps that naturally overlap and interlock with adjacent sheets, enabling the material to self-align and self-position without requiring manual intervention or complex positioning mechanisms, thereby achieving both wrinkle prevention and production stability

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The notches or cutouts are pre-formed in the prepreg sheets before the molding process. This preliminary action creates predetermined overlapping regions that will automatically engage during the molding process, ensuring proper alignment and preventing wrinkles before the actual forming occurs, thus improving both appearance quality and production stability

Inventive Principle:

Principle #10Preliminary action

2Shape

If manual laying of prepreg is used to overlap end edge parts of notches or cutouts, then high curvature shapes are formed, but productivity deteriorates

Engineering Contradiction:

Improvehigh curvature shapeVSAvoidproduction efficiency

Core Design Contradiction:

ShapeVSProductivity

Solution Approach 1:

The overlapping portions of the prepreg sheets serve as self-positioning features that automatically guide the laying process. The notches or cutouts create flaps that naturally overlap and interlock with adjacent sheets, enabling the material to self-align and self-position without requiring manual intervention or complex positioning mechanisms, thereby achieving both wrinkle prevention and production stability

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The notches or cutouts are pre-formed in the prepreg sheets before the molding process. This preliminary action creates predetermined overlapping regions that will automatically engage during the molding process, ensuring proper alignment and preventing wrinkles before the actual forming occurs, thus improving both appearance quality and production stability

Inventive Principle:

Principle #10Preliminary action

3Productivity

If insufficient or unstable overlapping of end edge parts is allowed, then productivity is improved, but wrinkle formation and fiber disorder increase

Engineering Contradiction:

Improveproduction speedVSAvoidwrinkle formation and fiber disorder

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The overlapping portions of the prepreg sheets serve as self-positioning features that automatically guide the laying process. The notches or cutouts create flaps that naturally overlap and interlock with adjacent sheets, enabling the material to self-align and self-position without requiring manual intervention or complex positioning mechanisms, thereby achieving both wrinkle prevention and production stability

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The notches or cutouts are pre-formed in the prepreg sheets before the molding process. This preliminary action creates predetermined overlapping regions that will automatically engage during the molding process, ensuring proper alignment and preventing wrinkles before the actual forming occurs, thus improving both appearance quality and production stability

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 method enables the stable and efficient production of fiber-reinforced composite materials with high curvature and uniform quality, preventing wrinkles and fiber disorder, resulting in improved strength and appearance, and can be applied to various complex shapes such as semi-spherical and container-like forms.

Implementation Method 1

press-molding is carried out by a press die

Methodology Applied

Scientific EffectPressure: Pressure Increase

Implementation Method 2

heating and curing are carried out to complete the molding process

Methodology Applied

Scientific EffectHeating: Heating

Data Source

PatentUS8790563B2Method of producing molded article of fiber-reinforced composite material and the molded article

Publication Date: 2014.07.29 MITSUBISHI CHEM CORP

AI summary

A method is presented for stably, highly, and efficiently producing a three-dimensional molded article of a fiber-reinforced composite material having a three-dimensional shape, uniform quality, and free from wrinkles by press molding a plurality of prepregs cut out in a predetermined shape and also to a molded article.