Molded Article Core Layer Geometry for Non-Circular Blow-Molding

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Solution Overview

Problem

Existing molded articles made from single materials face challenges in achieving non-circular symmetry during blow-molding, leading to structural weaknesses and process inefficiencies, particularly when transitioning from symmetric preforms to asymmetric containers.

Innovation Solution

A multi-layered molded article design with a core layer of varying radial thickness and materials, including a second polymeric material with higher intrinsic viscosity and thermal crystallization rate, to control non-uniform blow-molding and achieve aesthetic variations in the final container.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a symmetric preform is used for blow-molding, then the manufacturing process is simplified and material distribution is uniform, but the ability to produce non-circular symmetric containers is compromised and structural weaknesses occur

Engineering Contradiction:

Improvepreform manufacturing simplicityVSAvoidcontainer symmetry control

Core Design Contradiction:

Ease of manufactureVSShape

Solution Approach 1:

The core layer is designed with non-uniform radial thickness, creating localized regions of different thickness to control the blow-molding process. This allows specific areas of the preform to expand differently during blow-molding, enabling the production of non-circular symmetric containers while maintaining overall manufacturing simplicity

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention introduces asymmetry in the core layer geometry (non-uniform radial thickness) to break the circular symmetry of the preform. This controlled asymmetry in the core layer translates to controlled non-uniform expansion during blow-molding, allowing production of asymmetric container shapes while maintaining manufacturing efficiency

Inventive Principle:

Principle #4Asymmetry

2Device complexity

If a single-material preform is used, then the manufacturing process is simple and cost-effective, but the ability to enhance specific properties like oxygen impermeability is limited

Engineering Contradiction:

Improvematerial layer structureVSAvoidbarrier property

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The invention uses a multi-layer composite structure consisting of an outer layer, inner layer, and core layer made from different polymeric materials. The core layer material is specifically selected to provide enhanced barrier properties (oxygen impermeability) while the outer and inner layers provide structural integrity and moldability, creating a composite material system that achieves both simplicity and enhanced functionality

Inventive Principle:

Principle #40Composite materials

3Ease of manufacture

If uniform core layer thickness is used, then the manufacturing process is straightforward, but non-uniform blow-molding and aesthetic variations in the final container cannot be achieved

Engineering Contradiction:

Improvecore layer formation simplicityVSAvoidblow-molding control precision

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The core layer is designed with locally varied radial thickness, where different regions have different thicknesses. This local quality variation in the core layer directly controls the blow-molding process, allowing precise control over the expansion of different preform regions and enabling aesthetic variations in the final container shape and surface characteristics

Inventive Principle:

Principle #3Local quality

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 multi-layered design enables precise control over blow-molding processes, enhancing structural integrity and allowing for aesthetic variations in the final container, addressing the limitations of single-material preforms.

Implementation Method 1

the rate of thermal crystallization of the first polymeric material being substantially less than that of the second polymeric material

Methodology Applied

Scientific EffectThermal crystallization: Crystallisation

Implementation Method 2

a radial thickness of the core layer being selectively varied to govern non-uniform blow molding of the molded article into the final-shaped container

Methodology Applied

Scientific EffectBlow-molding:

Data Source

PatentUS20250256442A1Molded article with selectively varied core layer geometry and hot runner nozzles for producing same

Publication Date: 2025.08.14 HUSKY INJECTION MOLDING SYST LTD

AI summary

A molded article suitable for subsequent blow-molding into a final-shaped container. The article includes a neck portion; a gate portion; and a body portion extending between the neck portion and the gate portion, at least a majority of the body portion having an overall shape which is symmetric about a body axis extending longitudinally through a center of the body portion. The body portion includes an inner exterior layer and an outer exterior layer of a first polymeric material; and a core layer of a second polymeric material disposed between the inner exterior layer and the outer exterior layer. A radial thickness or a material of the core layer is selectively varied to govern non-uniform blow molding of the molded article into the final-shaped container.