Thermoplastic Cast with Foam Buffer Pad for Ventilation and Comfort

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Solution Overview

Problem

Conventional thermoplastic casts with mesh forms cause discomfort due to hard surfaces, poor ventilation, and increased inconvenience, especially when exposed to moisture, leading to pain and difficulty in bathing or showering.

Innovation Solution

A thermoplastic cast with a mesh structure and a buffer pad made of foam, where the foam is bonded to the structure using insert injection molding without adhesives, providing a Shore C hardness of 45 or less, and optionally covered with a rubber outer layer for additional cushioning and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a mesh form structure is used for the cast, then ventilation is improved, but the surface becomes hard and causes discomfort to the user

Engineering Contradiction:
ImproveventilationVSAvoidhard surface discomfort
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The cast combines a mesh form structure (providing ventilation) with a foam buffer pad layer (providing softness and comfort). This composite structure allows the cast to simultaneously achieve good ventilation through the mesh and comfort through the foam buffer, resolving the contradiction between ventilation and surface hardness.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If a lower pad is placed around the damaged area before the cast, then comfort is improved, but ventilation deteriorates and the pad becomes wet during showering

Engineering Contradiction:
ImprovecomfortVSAvoidventilation
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The foam buffer pad is integrated directly into the cast structure as an inherent component rather than being a separate lower pad. This merging eliminates the ventilation problem caused by separate pads while maintaining comfort, as the foam is directly bonded to the mesh structure and provides cushioning without trapping moisture.

Inventive Principle:
Principle #5Merging (Combining)

3Strength

If adhesive is used to bond the foam buffer pad to the structure, then bonding strength is improved, but manufacturing complexity and environmental harm increase

Engineering Contradiction:
Improvebonding strengthVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent replaces the chemical bonding method (adhesive) with a mechanical bonding method (insert injection molding). The foam buffer pad is injected directly into the mold cavity and mechanically interlocked with the mesh structure, eliminating the need for separate adhesive application steps and reducing manufacturing complexity while maintaining strong bonding.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If the cast is made to be durable and reusable, then durability is improved, but comfort may deteriorate due to hard surfaces

Engineering Contradiction:
ImprovedurabilityVSAvoidcomfort
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The cast uses a composite structure where the mesh form structure provides durability and structural integrity, while the foam buffer pad provides comfort and softness. This allows the cast to be both durable and comfortable, resolving the contradiction between durability and comfort.

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 cast provides improved comfort, ventilation, and durability by absorbing impacts and maintaining structural integrity, while allowing for easy cleaning and reuse, reducing user discomfort and inconvenience.

Implementation Method 1

absorb an impact applied to a damaged area

Methodology Applied
Scientific EffectImpact absorption: Damping

Implementation Method 2

The buffer pad may be bonded to the structure by insert injection molding without using an adhesive

Methodology Applied
Scientific EffectInsert injection molding:

Data Source

PatentEP3332753B1Thermoplastic cast
Publication Date: 2023.04.26 OPENM INC
  • EP3332753B1 patent drawingFigure 1
  • EP3332753B1 patent drawingFigure 2
  • EP3332753B1 patent drawingFigure 3

AI summary

A thermoplastic cast according to an embodiment of the present invention includes a structure having a mesh form and a thermoplastic property, an outer cover provided on an outer surface of the structure, a buffer pad provided on an outer surface of the outer cover and having elasticity, and a finishing material provided on an outer surface of the buffer pad and configured to come into contact with a user's body. Melting points of the outer cover, the buffer pad, and the finishing material are higher than that of the structure. The finishing material has a porosity different from that of the buffer pad.