Foam Molded Product with Compressive Deformation Layer

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional foam molded products face challenges in achieving high surface smoothness, excellent design surface mold followability, and rigidity due to issues such as contraction deformation, poor mold followability, and light scattering from pre-expanded particles, which affect their impact resistance and scratch resistance.

Innovation Solution

A foam molded product with a three-layer structure comprising a surface layer, a compressive deformation layer, and a foam layer, where the compressive deformation layer is formed using pre-expanded particles with specific hardness and a controlled compression ratio to prevent contraction stress transmission and enhance mold followability and rigidity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the surface of the foam molded product is melted to form a non-foam layer, then scratch resistance and rigidity of the surface are improved, but the foam layer below is simultaneously heated causing contraction deformation during cooling

Engineering Contradiction:
Improvescratch resistanceVSAvoidcontraction deformation
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The foam molded product is divided into distinct layers: a skin material layer (0.1-5.0mm thick) that provides surface strength and scratch resistance, and a foam layer beneath that provides shock absorption and impact resistance. This segmentation allows each layer to perform its specific function without interfering with the other, preventing contraction deformation while maintaining surface quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses a composite structure combining a skin material (solid resin or fiber-reinforced material) with a foam material. This composite approach allows the skin material to provide the necessary surface strength and scratch resistance, while the foam layer provides shock absorption, resolving the contradiction between surface strength and contraction deformation.

Inventive Principle:
Principle #40Composite materials

2Shape

If a compressed layer is formed at the surface to improve surface smoothness, then high strength and smooth surface are achieved, but a turtle shell pattern of interfaces remains and mold followability significantly decreases

Engineering Contradiction:
Improvesurface smoothnessVSAvoidmold followability
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The skin material layer is applied only at the surface region where smoothness and mold followability are required, while the foam layer maintains its cellular structure in the interior regions where shock absorption is needed. This local differentiation resolves the contradiction between surface smoothness and overall mold followability.

Inventive Principle:
Principle #3Local quality

3Shape

If a thin skin material is used to provide design surface, then exterior appearance is improved, but undulations of the foam molded product surface are transferred to the skin material reducing texture quality

Engineering Contradiction:
Improveexterior appearanceVSAvoidtexture quality
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The foam layer acts as a cushioning layer between the mold surface and the thin skin material layer. It absorbs and isolates undulations and irregularities from being transferred to the skin material, allowing the skin material to maintain high texture quality and exterior appearance without being affected by underlying surface imperfections.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

4Weight of moving object

If the foam molded product is used as structural material replacing solid resin, then low density and high heat insulation are achieved, but impact resistance and scratch resistance become poor

Engineering Contradiction:
ImprovedensityVSAvoidimpact resistance
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The foam molded product is segmented into a skin material layer for surface protection and a foam layer for core functionality. The skin material layer provides scratch resistance and impact resistance, while the foam layer provides low density and heat insulation, resolving the contradiction between weight reduction and strength enhancement.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention creates a composite material structure combining skin material with foam material. This allows the product to simultaneously exhibit the light weight and heat insulation properties of foam, along with the surface strength and scratch resistance of solid resin or fiber-reinforced materials.

Inventive Principle:
Principle #40Composite materials

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 solution provides a foam molded product with high surface smoothness, excellent design surface mold followability, and improved rigidity, enabling its use in structural components like engine covers while maintaining mechanical strength and impact resistance.

Implementation Method 1

heating pre-expanded particles to perform melting and compressive deformation

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

compressing the foam product to mold dimensions through a pressing mechanism to form a surface layer and a compressive deformation layer

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 3

cooling the mold to solidify the surface layer and obtain a foam molded product

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentEP3778177B1Foam molding and method for producing same
Publication Date: 2022.04.27 ASAHI KASEI KOGYO KABUSHIKI KAISHA
  • EP3778177B1 patent drawingFigure 1
  • EP3778177B1 patent drawingFigure 2
  • EP3778177B1 patent drawingFigure 3

AI summary

Provided are a foam molded product and a method of producing the same. The foam molded product is a molded product containing a resin and including a surface layer, a compressive deformation layer, and a foam layer. The thickness of the surface layer is 0.1 mm to 5.0 mm. The compressive deformation layer is located between the surface layer and the foam layer. Foam particles forming the compressive deformation layer have an average H/L of 0.5 or less (H: length in compression direction; L: length in perpendicular direction relative to compression direction). Foam particles forming the foam layer have an expansion ratio of not less than 3.0 times and less than 30 times.