Self-Collapsing Blow-Molded Thin-Walled Container

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Solution Overview

Problem

Existing large-capacity plastic jugs for water dispensing units are cumbersome, prone to mechanical damage, and suffer from air contamination during use, posing handling and sanitary issues, while previous thin-walled container solutions lack sufficient volume capacity and durability.

Innovation Solution

Development of blow-molded plastic thin-walled containers with a self-collapsing design, featuring a collapsible structure that maintains airtightness and mechanical strength, allowing for efficient handling and storage, and utilizing a manufacturing method involving stretch blow molding with specific stretching ratios and structural features like transversal grooves and retractable parts for enhanced compactability and ease of use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the wall thickness of plastic jugs is increased to 400-1500 μm to improve mechanical strength and resistance to abrasion, then the jugs become difficult to lift and manoeuvre due to increased weight and bulk

Engineering Contradiction:
Improvemechanical strength and resistance to abrasionVSAvoidweight and bulk
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The invention divides the container into two distinct parts: a thin-walled collapsible body (50-200 μm) for liquid storage and a separate thick-walled rigid base (400-1500 μm) for mechanical support. This segmentation allows each part to optimize its thickness for its specific function, resolving the contradiction between overall strength and weight.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention applies different wall thicknesses to different parts of the container based on local functional requirements. The base and neck areas receive thick walls (400-1500 μm) for structural integrity and abrasion resistance, while the body uses thin walls (50-200 μm) to minimize weight and enable collapsibility.

Inventive Principle:
Principle #3Local quality

2Weight of moving object

If thin-walled bottles are used to reduce weight and improve handling, then they become prone to mechanical damage and lack sufficient durability for returnable and refillable use

Engineering Contradiction:
ImproveweightVSAvoiddurability and resistance to mechanical damage
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The invention applies different wall thicknesses to different parts of the container based on local functional requirements. The base and neck areas receive thick walls (400-1500 μm) for structural integrity and abrasion resistance, while the body uses thin walls (50-200 μm) to minimize weight and enable collapsibility.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The container functions as a composite structure combining thin-walled flexible plastic for the body with thick-walled rigid plastic for the base and neck, creating a hybrid system that exhibits both collapsibility and mechanical durability.

Inventive Principle:
Principle #40Composite materials

3Strength

If rigid jugs are used to maintain structural integrity, then air enters the liquid during sampling to compensate for sampled volume, causing contamination

Engineering Contradiction:
Improvestructural integrityVSAvoidair contamination of liquid
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The invention transforms the static rigid structure into a dynamic collapsible structure. The thin-walled body can deform and collapse as liquid is dispensed, maintaining a seal that prevents air from entering the liquid, thereby eliminating contamination while preserving structural integrity through the rigid base.

Inventive Principle:
Principle #15Dynamics

4Productivity

If empty jugs are made rigid and returnable for refilling, then they require washing and treatment involving sanitary issues and organization of delivery circuits

Engineering Contradiction:
Improvereusability and refillabilityVSAvoidsanitary management and delivery circuit organization
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The invention employs a disposable thin-walled container design that eliminates the need for complex washing and refilling circuits. The thin-walled body can be easily separated and discarded after use, significantly simplifying sanitary management and logistics while maintaining productivity through continuous availability of new containers.

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

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 solution provides a cost-effective, airtight, and durable thin-walled container that can handle large volumes, prevents air contamination during use, and facilitates easy handling and storage by self-collapsing when empty, addressing the issues of bulkiness and sanitary concerns of previous designs.

Implementation Method 1

heating and stretching, in the axial and radial directions, by blow molding

Methodology Applied
Scientific EffectHeat treatment: Heat Treatment

Implementation Method 2

blow molding of a preform, with heating and stretching, in the axial and radial directions

Methodology Applied
Scientific EffectBlow molding:

Implementation Method 3

which, when empty, is capable of collapsing, under the effect of its own weight, in the axial direction

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP2938546B1Self collapsible blow moulded plastic thin-walled container
Publication Date: 2018.09.05 SOCIETE ANONYME DES EAUX MINERALES D EVIAN SAEME
  • EP2938546B1 patent drawingFigure 1A
  • EP2938546B1 patent drawingFigure 1B
  • EP2938546B1 patent drawingFigure 1A'~1D

AI summary

A blow molded bottle (1): a) which is self-collapsable during its emptying; b) which comprises at least two transversal grooves and/or ribs (6.1), preferably located in the tubular body portion (6), equipped with collapse starters (6.2); c) wherein the mean wall thickness (Tmean) of the tubular body portion (6) is - in an increasing order of preference - less than or equal to 200 μm preferably comprised between 90 and 130 μm. The invention also concerns a method, a preform (100) and a mold for the manufacture of said aforementioned container by blow moulding. The invention also concerns a method for bottling liquid into said bottles (1), a method for dispensing said liquid, a dispenser for implementing said method and a method for packing the thin-walled bottles, in view of storage and transportation.