Multilayer Container Mold Flow Inhibition Design

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Solution Overview

Problem

Current multi-layer container manufacturing methods face challenges in achieving both excellent delamination resistance and gas barrier properties without increasing production costs or using complex molding processes, as existing methods often require special apparatus or result in poor shape formation.

Innovation Solution

A mold design with a hot-half portion and a cold-half portion, featuring a junction portion upstream of the gate and a second resin flow path with convex portions to inhibit resin flow, allowing for a laminate structure with a concave gas barrier layer that suppresses delamination and enhances gas barrier properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a multi-layer container is manufactured using conventional injection molding methods, then the production cost is reduced and the process is simplified, but delamination occurs between different resin layers resulting in poor gas barrier property

Engineering Contradiction:
Improvedelamination resistanceVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention introduces a flow inhibition means in the resin flow path before injection, which preliminarily controls the resin flow pattern. This preliminary action creates a specific flow state that prevents delamination during subsequent injection and molding processes, solving the delamination problem without requiring complex post-processing or special molding techniques

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The flow inhibition means acts as an intermediary element in the resin flow path. It mediates between the resin injection system and the mold cavity, controlling the resin flow to achieve uniform layer formation and prevent delamination without requiring changes to the resin materials or complex molding procedures

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If special back flow control apparatus is used to prevent delamination, then delamination resistance is improved, but production cost increases

Engineering Contradiction:
Improvedelamination resistanceVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention replaces expensive special back flow control apparatus with a simple, inexpensive flow inhibition means integrated into the mold. This simple structure achieves the same delamination prevention effect without the high cost of complex control systems, making the solution economically viable for mass production

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The invention extracts the essential function of flow control from complex back flow control apparatus and implements it through a simple flow inhibition means in the resin flow path. This extraction eliminates unnecessary complexity and cost while maintaining the delamination prevention function

Inventive Principle:
Principle #2Taking out (Extraction)

3Object-affected harmful factors

If conventional molding methods are used, then production cost is reduced, but gas barrier property is insufficient due to delamination

Engineering Contradiction:
Improvegas barrier propertyVSAvoidmanufacturing process simplicity
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The flow inhibition means performs preliminary control of resin flow to ensure proper layer formation and bonding before the actual injection and molding. This preliminary action prevents delamination that would compromise gas barrier property, achieving excellent oxygen and carbon dioxide barrier performance with a simple modified molding process

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the flow parameters of the resin by introducing the flow inhibition means, which controls the resin flow rate and distribution. This parameter change ensures uniform resin distribution and proper layer adhesion, improving gas barrier property without requiring complex multi-step processes

Inventive Principle:
Principle #35Parameter changes

4Reliability

If complex molding processes are applied to improve delamination resistance, then delamination resistance is improved, but the shape formation of the container becomes poor

Engineering Contradiction:
Improvedelamination resistanceVSAvoidcontainer shape formation
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The flow inhibition means performs preliminary flow control that simultaneously improves delamination resistance and shape formation. By controlling the resin flow pattern before injection, it ensures proper layer adhesion while maintaining excellent shape formation, eliminating the need for complex post-molding processes that might compromise shape quality

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2561970B1Multilayered container, die for multilayered container, and method for producing multilayered container
Publication Date: 2021.07.21 MITSUBISHI GAS CHEM CO INC
  • EP2561970B1 patent drawingFigure 1~3
  • EP2561970B1 patent drawingFigure 4~6(d)
  • EP2561970B1 patent drawingFigure 7(a)~8

AI summary

Provided is a multi-layer container excellent in delamination resistance and gas barrier property, which can be manufactured without employing any molding method involving a special apparatus, which increases a production cost, and a complicated step. Specifically, the multi-layer container includes a laminate structure of three or more layers having at least a gas barrier layer between an innermost layer and an outermost layer, in which the gas barrier layer in a site formed of the laminate structure has a portion having a thickness 0.01 to 0.9 times as large as the maximum thickness of the gas barrier layer. Further, provided are a mold suitable for manufacturing the multi-layer container, and a manufacturing method for a multi-layer container using the mold.