Shoe Sole Shaping Insert for Multi-Density Injection Molding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing multi-density shoe soles are complex and require extensive machinery, making it difficult to achieve localized variations in density and design without significant modifications to the mould and tooling.
Innovation Solution
A shoe sole shaping insert is placed inside the injection chamber to create cavities for different sole materials, allowing for multi-density soles to be manufactured without removable mould plates or differently shaped pistons, enabling swift design changes and precise material composition adjustments without altering the machinery or tooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If removable mould plates are used to create cavities for different sole materials, then multi-density soles can be manufactured with localized variations, but the device complexity and machinery requirements increase significantly
Solution Approach 1:
The invention extracts the cavity-forming function from the permanent mould structure and places it in a temporary insert that can be easily inserted and removed. This allows the mould to transition between single-density and multi-density configurations without requiring complex removable plate mechanisms or automated arm systems.
Solution Approach 2:
The insert acts as a temporary, easily replaceable component that defines the cavity shape only during the injection process. After injection, the insert is removed and can be replaced with a different insert for design variations, eliminating the need for expensive, complex tooling changes.
2Manufacturing precision
If removable mould plates are used for multi-density sole production, then different density areas can be created, but the mould height increases and requires additional space in the factory
Solution Approach 1:
The insert is nested inside the injection chamber, fitting within the existing mould cavity space. This nested configuration allows the insert to define localized cavities without increasing the overall mould height, as the insert occupies the same vertical space that would otherwise be filled with single-density material.
3Manufacturing precision
If conventional moulds are modified to manufacture multi-density soles, then localized material variations are achieved, but the cost and time for tooling modifications increase
Solution Approach 1:
The invention segments the cavity definition function into a separate, interchangeable insert component. This allows the main mould structure to remain unchanged while the insert can be easily modified or replaced to achieve different density distributions, material compositions, and visual appearances without expensive tooling rework.
Solution Approach 2:
By changing the insert geometry or material properties, the patent enables rapid adjustment of the sole's density distribution, material composition, and visual characteristics. This parameter-based control through insert variation is much more cost-effective than modifying the permanent mould structure.
4Measurement precision
If automated mechanical arms are used to move removable plates, then plate positioning is precise, but the factory space requirements and operational complexity increase
Solution Approach 1:
The insert is designed to be self-positioning within the injection chamber, utilizing the existing mould geometry and injection mechanisms for accurate placement. This eliminates the need for external automated positioning systems, reducing factory space requirements while maintaining positioning precision through the insert's geometric fit with the mould cavity.
Data Source
AI summary
A method for manufacturing a multi-density shoe sole is described, the method incorporates repeated injections of sole material onto a shoe upper mounted on a last and placed in a mold. The mold has an injection chamber, moveable side frames, a vertically moveable bottom piston and a shoe sole shaping insert which is placed in the mold prior to a first injection and removed from the mold after said first injection and prior to a second injection. The entire body of the shoe sole shaping insert is placed inside the injection chamber during the first injection. The shoe sole shaping insert acts as a dummy during the first injection, and leaves after its removal a cavity which in a later injection step is filled with another sole material, either another color or another density. Also disclosed is an insert used in a mold for injection molding of shoe soles.