Separable Shoe Insert for Injection Molding

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for manufacturing shoe parts by injection molding are complicated and expensive due to the need for multiple injection channels, unsuitable for producing sole parts under the outsole, and result in melt scars on heel caps, limiting versatility and efficiency.

Innovation Solution

A method using separable shoe part shaping inserts with an upper and lower part, where the injection channel is placed between them, allowing for single-channel injection and subsequent separation to avoid visible melt impressions, enabling multi-density shoe part production without changing molds or pistons, and allowing for different material compositions and designs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple injection channels are placed in the mould to produce different shoe parts, then the ability to produce multiple shoe parts is improved, but the mould complexity and cost increase

Engineering Contradiction:

Improveability to produce multiple shoe partsVSAvoidmould complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The insert is divided into separable parts (first insert part and second insert part) that can be independently removed from the mould. This allows the injection channel to be segmented between the insert and mould, enabling single-channel injection for multiple parts without increasing mould complexity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The insert acts as an intermediary carrier that holds the injection channel and guides the injected material to different cavities. By placing the injection channel in the insert rather than directly in the mould, the system achieves multi-part production capability while keeping the mould structure simple

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If the injection outlet is placed on the visible back surface of the heel cap, then the injection process is simplified, but a melt scar is created on the visible surface

Engineering Contradiction:

Improveinjection process simplicityVSAvoidmelt scar on visible surface

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

Instead of placing the injection outlet on the visible surface, the outlet is inverted to the non-visible surface of the heel cap. The insert structure allows the material to be injected from the non-visible surface and flow through the heel cap interior, eliminating visible melt scars while maintaining manufacturing simplicity

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The insert structure creates different surface qualities: the visible surface of the heel cap has no injection outlet (avoiding scars), while the non-visible surface contains the outlet. This local differentiation resolves the conflict between ease of injection and surface quality

Inventive Principle:

Principle #3Local quality

3Device complexity

If a single injection channel is used in the mould, then the mould complexity is reduced, but the ability to produce multiple shoe parts with different densities is limited

Engineering Contradiction:

Improvemould simplicityVSAvoidability to produce multi-density shoe parts

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The insert is made dynamically removable and replaceable. Different insert configurations can be used for different injection cycles, allowing a single mould with simple structure to produce multiple shoe parts with different densities by changing the insert rather than the mould

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

By changing the insert configuration (different densities, shapes, or materials) while keeping the mould structure constant, the system achieves versatility in producing different shoe parts. The insert parameters can be varied without modifying the mould

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

This approach simplifies the manufacturing process, reduces costs, and allows for the production of complex shoe parts with varied densities and designs without visible melt scars, enhancing design flexibility and efficiency.

Implementation Method 1

a method for manufacturing one or more shoe parts by injection moulding of a material onto a shoe upper mounted on a last and injecting said material into a mould

Methodology Applied

Scientific EffectInjection molding:

Implementation Method 2

The mould is then opened after the material has cured

Methodology Applied

Scientific EffectCuring:

Data Source

PatentUS9764521B2Shoe part shaping insert to be placed in a mold

Publication Date: 2017.09.19 ECCO SKO A S

AI summary

The invention relates to a method for manufacturing a shoe part by injection molding a material into a mold where an insert is placed. The insert comprises at least two separable insert parts, an upper insert part and a lower insert part, providing an injection channel in the region of the separation area between the two parts. The insert is placed in the chamber and the injection material is injected through a sprue channel in the mold into the injection channel and into a cavity, whereby the shoe part is formed. The mold is opened after the injection material has cured and the insert is separated into the upper and lower insert parts, thereby exposing the cured material in the injection channel.