Integrated Molded Part Structure for Deformation-Safe Resin Joining

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for connecting fiber-reinforced resin members to frame structures face challenges such as deformation during integral molding, adhesive removal difficulties, and increased weight due to resin overflow, which compromise mechanical properties and efficiency in mass production.

Innovation Solution

An integrated molded part design comprising a structural member, resin structural member, and protective member, where the protective member's softening temperature exceeds both the resin and structural member's glass transition temperatures, ensuring controlled molding and preventing resin intrusion, with specific temperature and material relationships to maintain dimensional accuracy and lightweight properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a structural member is formed by injection molding, then integration with frame material is achieved, but the structural member may be deformed by heat transfer from the injected resin

Engineering Contradiction:
Improveintegration of structural member and frame materialVSAvoiddimensional accuracy of structural member
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by pre-heating the injected resin to a temperature below the glass transition temperature of the structural member before injection. This preliminary temperature control prevents thermal deformation of the structural member during the molding process, while still allowing integration to be achieved.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If a relatively large amount of adhesive is applied to ensure joint reliability, then joint strength is improved, but the burden of removing excessive adhesive increases

Engineering Contradiction:
Improvejoint reliabilityVSAvoidmass production efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent extracts the harmful element (excessive adhesive) from the system by applying adhesive control technology that limits adhesive to only the necessary amount for joint formation. This eliminates the need for adhesive removal operations, improving productivity in mass production while maintaining joint reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

3Strength

If the structural member is deformed during molding, then mechanical properties are deteriorated, but also resin flows into the deformed portion causing weight increase

Engineering Contradiction:
Improvemechanical propertiesVSAvoidweight of molded part
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent applies preliminary action by pre-controlling the temperature of the injected resin to prevent structural member deformation before it occurs. This prevents both the mechanical property deterioration and the subsequent resin overflow that would cause weight increase, addressing both issues simultaneously through proactive temperature management.

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

The integrated molded part suppresses deformation during molding, achieving high accuracy and stability in weight and dimensions, while maintaining mechanical integrity and reducing the need for adhesive removal, thus enhancing production efficiency.

Implementation Method 1

a glass transition temperature Ta (°C) of the structural member (a) and the softening temperature Tc (°C) of the protective member (c) satisfy the following relationship: Tc>Ta

Methodology Applied
Scientific EffectGlass transition temperature:

Implementation Method 2

the protective member (c) is in contact with both the structural member (a) and the resin structural member (b), and a softening temperature Tb (°C) of the resin structural member (b) and a softening temperature Tc (°C) of the protective member (c) satisfy the following relationship: Tc>Tb

Methodology Applied
Scientific EffectThermal protection: Thermal Insulation

Data Source

PatentEP4659932A1Integrally-molded product and method for manufacturing integrally-molded product
Publication Date: 2025.12.10 TORAY INDUSTRIES INC
  • EP4659932A1 patent drawingFigure 1A~3E
  • EP4659932A1 patent drawingFigure 4A~5B
  • EP4659932A1 patent drawing

AI summary

An integrated molded part of a structural member and a resin structural member in which deformation of the structural member that may occur during integral molding is suppressed and which has high accuracy in weight and dimensions is realized. An integrated molded part including a structural member (a), a resin structural member (b), and a protective member (c), wherein the protective member (c) is in contact with both the structural member (a) and the resin structural member (b), and a softening temperature Tb (°C) of the resin structural member (b) and a softening temperature Tc (°C) of the protective member (c) satisfy the following relationship. Tc>Tb