Fiber Width Adjustment Device Using Twisted Tape Overlap

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Solution Overview

Problem

Existing methods for adjusting the width of prepreg tapes or dry tapes for fiber reinforced plastics (FRP) molding are unstable and often result in uneven thickness and width due to contact with walls, leading to folds and difficulty in restoring the original width.

Innovation Solution

A fiber width adjustment device using a twisting mechanism and pressure unit to overlap and compress prepreg tapes, allowing for stable width adjustment by twisting and cutting the tapes, ensuring uniform thickness and responsiveness to width changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a width adjustment device is proposed to change the width of prepreg tapes or dry tapes by making them pass through a path whose width gradually decreases, then the width of the tape can be adjusted, but the adjustment is unstable and results in uneven thickness and width due to contact with walls

Engineering Contradiction:
Improvewidth adjustment precisionVSAvoidadjustment stability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The width adjustment process is segmented into two distinct stages: first, a twisting mechanism overlaps the tape in the width direction by twisting it; second, a pressure unit presses the overlapped tape in the thickness direction to produce a sheeted tape with adjusted width. This segmentation eliminates the instability caused by continuous narrowing paths and contact with walls.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of narrowing the path to adjust width (which causes instability), the invention inverts the approach by using a twisting mechanism to overlap the tape and then applying pressure. This reverse methodology achieves width adjustment without the harmful contact effects of the conventional narrowing path approach.

Inventive Principle:
Principle #13The other way round (Inversion)

2Manufacturing precision

If the tape is made to pass through a narrowing path to adjust width, then width change is achieved, but folds occur and restoration to original width becomes difficult

Engineering Contradiction:
Improvewidth adjustmentVSAvoidrestoration capability
Core Design Contradiction:
Manufacturing precisionVSEase of repair

Solution Approach 1:

The twisting mechanism performs preliminary overlapping action before the pressure unit applies final compression. This preliminary twisting creates a controlled overlap structure that can be precisely managed, preventing random folds and enabling easier restoration if needed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The twisting mechanism acts as an intermediary between the original tape and the final pressed configuration. It creates a controlled intermediate state (overlapped tape) that transitions smoothly to the final width-adjusted state, preventing direct contact-induced folds that would occur in narrowing path methods.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If conventional width adjustment methods are used, then some width change is achieved, but uniform thickness and reproducible width characteristics cannot be ensured

Engineering Contradiction:
Improvewidth uniformityVSAvoidreproducibility
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The pressure unit applies controlled pressure to the overlapped tape to produce a sheeted tape with uniform thickness. This pressing action provides feedback control that ensures consistent width and thickness characteristics across multiple operations, achieving reproducible results that conventional methods cannot attain.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The invention changes the physical state and parameters of the tape through a two-stage process: first twisting to overlap (changing geometric configuration), then pressing in the thickness direction (changing density and thickness parameters). These controlled parameter changes ensure uniform width and reproducible characteristics.

Inventive Principle:
Principle #35Parameter changes

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

The device enables precise and uniform width adjustment of prepreg tapes, preventing folds and ensuring reproducible, transient width characteristics, enhancing the stability and quality of FRP molding processes.

Implementation Method 1

The twisting mechanism is configured to overlap the tape in a width direction of the tape by twisting the tape

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

The pressure unit is configured to produce a sheeted tape, having an adjusted width, by pressing the overlapped tape in a thickness direction of the overlapped tape

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP4578638A1Fiber width adjustment device and method of molding composite material
Publication Date: 2025.07.02 SUBARU CORP
  • EP4578638A1 patent drawingFigure 1
  • EP4578638A1 patent drawingFigure 2
  • EP4578638A1 patent drawingFigure 3(A)~3(C)

AI summary

A fiber width adjustment device is for adjusting a width of a tape made of fibers before or after being impregnated with resin. The tape is a material for a fiber reinforced plastic. The fiber width adjustment device includes a twisting mechanism and a pressure unit. The twisting mechanism is configured to overlap the tape in a width direction of the tape by twisting the tape. The pressure unit is configured to produce a sheeted tape, having an adjusted width, by pressing the overlapped tape in a thickness direction of the overlapped tape.