Mould Bottom Mesh Posts for Blow Molding Heat Exchange

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Solution Overview

Problem

Current mold bases for blow molding and stretch blow molding face challenges in achieving homogeneous heat exchange and mechanical strength, particularly at the mold bottom, due to complex shapes and limited manufacturing techniques, leading to inefficiencies in thermal regulation and increased maintenance needs.

Innovation Solution

A one-piece mold base with a mesh of posts extending over a portion of the cavity, where each post forms an angle between 0° and 45° with the mold bottom's longitudinal axis, connected by flares to the internal surface, promoting fluid circulation and turbulence for enhanced heat exchange while maintaining mechanical strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If transverse channels are drilled in the base to improve heat exchange efficiency, then heat exchange efficiency is improved, but manufacturing complexity increases and sealing difficulties arise at interfaces

Engineering Contradiction:
Improveheat exchange efficiencyVSAvoidfluid circuit complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent merges the fluid circuit into the mold base itself by creating a cavity within the base that receives the fluid, eliminating the need for separate drilled channels and reducing manufacturing complexity while maintaining heat exchange efficiency

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent uses a mesh structure with multiple posts that creates a porous-like configuration for fluid circulation, allowing efficient heat exchange across the mold bottom surface without requiring complex sealed channels

Inventive Principle:
Principle #31Porous materials

2Temperature

If channels are drilled close to the internal surface to maximize heat transfer, then heat transfer efficiency is maximized, but the risk of opening onto the molding surface increases

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidmolding surface integrity
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent moves the fluid circuit from a horizontal channel configuration close to the surface to a vertical cavity configuration within the base, eliminating the risk of opening onto the molding surface while maintaining thermal contact through the base thickness

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The mesh of posts acts as an intermediary structure between the fluid cavity and the molding surface, allowing heat transfer while physically separating the fluid circuit from the molding surface to prevent opening

Inventive Principle:
Principle #24Intermediary (Mediator)

3Temperature

If a serpentine channel is milled to improve heat exchange homogeneity, then heat exchange homogeneity is improved, but manufacturing complexity and maintenance difficulty increase

Engineering Contradiction:
Improveheat exchange homogeneityVSAvoidmanufacturing simplicity
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The patent segments the fluid circuit into multiple smaller channels formed by the mesh of posts, creating homogeneous heat exchange across the surface while using simple vertical post structures that are easier to manufacture than complex serpentine channels

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the geometric parameters of the fluid circuit from continuous serpentine channels to a discrete mesh of vertical posts, simplifying manufacturing while achieving homogeneous heat distribution through the segmented structure

Inventive Principle:
Principle #35Parameter changes

4Temperature

If the mold bottom volume is increased to accommodate fluid circuits, then heat exchange capacity is improved, but space constraints in the crowded blow mold environment are violated

Engineering Contradiction:
Improveheat exchange capacityVSAvoidmold bottom volume
Core Design Contradiction:
TemperatureVSVolume of stationary object

Solution Approach 1:

The patent uses a thin-walled cavity structure within the mold base that accommodates the fluid circuit with minimal volume occupation, allowing efficient heat exchange without increasing the overall mold bottom volume

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent nests the fluid circuit cavity within the existing mold base structure, placing the fluid channels inside the base thickness rather than adding external volume, thus maintaining compact dimensions while providing adequate heat exchange capacity

Inventive Principle:
Principle #7Nested doll (Nesting)

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 design improves heat exchange homogeneity and mechanical strength, simplifies manufacturing, reduces maintenance, and ensures better fluid circulation, resulting in higher quality containers and reduced thermal inertia.

Implementation Method 1

a cavity (4) intended to receive a heat transfer fluid... for the circulation of the heat transfer fluid in the cavity

Methodology Applied
Scientific EffectHeat exchange: Convection

Implementation Method 2

heat exchange between the fluid and the material of the container

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

promoting fluid circulation and turbulence for enhanced heat exchange

Methodology Applied
Scientific EffectTurbulence: Turbulence

Data Source

PatentEP3880432B1Mould bottom for a mould for manufacturing thermoplastic containers
Publication Date: 2022.08.31 SIDEL PARTICIPATIONS SAS
  • EP3880432B1 patent drawingFigure 1
  • EP3880432B1 patent drawingFigure 2
  • EP3880432B1 patent drawingFigure 3~4

AI summary

The invention relates to a single-piece mould bottom (1) for a mould for producing containers by blow moulding or stretch blow moulding from plastic preforms, the mould bottom (1) comprising: - a moulding wall (2), - a cavity (4) intended to receive a heat-transfer fluid, delimited by a surface envelope including an inner surface (21) of the moulding wall (2), - a meshwork (6) of posts (61) extending into the cavity (4), characterised in that each post (61) is connected to the internal surface (21) of the moulding wall (2) by a first widening (62) of material, and in that a first section between the connection of the first widening (62) of material with the inner surface (21) of the moulding wall (2) defines, with a second section of the post (61), a ratio of between 10 and 15.