Stretch Blow-Molded Container Shoulder Hinge Design

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Plastic containers produced through stretch blow molding often deform due to volume changes in filled products, leading to instability and external appearance issues, which existing solutions address by increasing wall thickness or using complex and costly flexible bases, but these solutions are not cost-effective or practical for widespread use.

Innovation Solution

A plastic container design featuring at least two hinge-like areas in the shoulder section with reduced wall thickness, allowing axial mobility of the container neck to compensate for volume changes, such as vacuum formation or expansion, while maintaining stability and ease of production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If wall thickness is increased to prevent deformation, then container strength is improved, but manufacturing cost and weight increase

Engineering Contradiction:
Improvecontainer strengthVSAvoidmanufacturing cost
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent applies local quality by creating hinge-like areas with reduced wall thickness only in specific locations where flexibility is needed, rather than uniformly increasing wall thickness throughout the container. This allows the container to deform locally at the hinge areas to compensate for volume changes, preventing overall deformation while using less material and reducing manufacturing costs.

Inventive Principle:
Principle #3Local quality

2Stability of the object's composition

If flexible base is used to compensate volume changes, then container stability is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvecontainer stabilityVSAvoidstructure complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent segments the shoulder section into multiple hinge-like areas, each capable of independent deformation. This segmentation allows the container to compensate for volume changes through distributed local deformations rather than requiring a complex flexible base structure, thereby maintaining stability while reducing device complexity.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If hinge-like areas with reduced wall thickness are created, then adaptability to volume changes is improved, but local strength decreases

Engineering Contradiction:
Improveadaptability to volume changesVSAvoidlocal strength
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The patent utilizes flexible shells by creating hinge-like areas with reduced wall thickness that can bend and deform elastically. These thin-walled hinge areas act as flexible elements that accommodate volume changes through controlled deformation, while the overall container structure maintains sufficient strength through the combination of these flexible zones with adjacent stiffer sections.

Inventive Principle:
Principle #30Flexible shells and thin films

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 effectively compensates for volume changes without significant weight or material increases, ensuring stability and maintaining the container's appearance, allowing for cost-effective production and use with various closure parts, including those that enable upside-down storage.

Implementation Method 1

The shoulder portion (4) has at least two circumferentially extending hinge-like areas (7, 8) which are spaced apart and have a reduced wall thickness relative to the adjacent portions

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3212372B1Stretch blow-molded plastic container, in particular plastic bottle, for compensating volume changes of the filling material, and preform
Publication Date: 2020.03.18 ALPLA WERKE ALWIN LEHNER
  • EP3212372B1 patent drawingFigure 1~3b
  • EP3212372B1 patent drawingFigure 4a~5b
  • EP3212372B1 patent drawingFigure 6~7

AI summary

The invention relates to a plastic container (1), which has a container body, the one longitudinal end of which is closed by a container bottom and the other longitudinal end of which is adjoined by a shoulder segment, and a container neck, which adjoins the shoulder segment. The shoulder segment has at least two hinge-like regions (7, 8) extending in the circumferential direction, which regions are arranged at a distance from each other and have a wall thickness that is reduced in comparison with the adjoining regions. The stretch blow-molded plastic container has a total stretch ratio greater than 11 and a longitudinal stretch ratio of 2.5 to 3.5.