Stretch Blow Moulded Polyester Shell for Liquid Container Burst Strength
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Solution Overview
Problem
Existing containers for liquids, especially those with high internal pressures, are prone to explosive bursting when damaged, posing safety risks due to the high energy content of pressurized gas, and fail to maintain pressure effectively at elevated temperatures, leading to gas loss and quality deterioration in beverages.
Innovation Solution
A container with a stretch blow moulded polyester shell that envelops the casing, providing increased burst strength and resistance to explosive bursting, while allowing the casing to expand gradually rather than explosively, and featuring a design that is lighter and more resistant to damage, with embossing for enhanced puncture resistance and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a lightweight casing is used for the container, then the container weight is reduced, but the burst strength and resistance to explosive bursting is insufficient
Solution Approach 1:
The container combines a lightweight blow-moulded casing (PET or similar plastic) with an enveloping shell made of stretch blow-moulded polyester. This composite structure provides both weight reduction and enhanced burst strength, as the shell reinforces the lightweight casing without significantly increasing overall weight.
Solution Approach 2:
The shell envelops the casing in a nested configuration, where the inner casing holds the liquid and the outer shell provides structural reinforcement. This nested arrangement allows the lightweight casing to maintain its weight advantage while the outer shell adds the necessary burst strength and resistance to explosive failure.
2Strength
If the container is made with sufficient thickness to prevent explosive bursting, then the burst strength is improved, but the container weight increases
Solution Approach 1:
Instead of uniformly thickening the casing, the invention uses a composite structure where a thin lightweight casing is reinforced by an enveloping shell. This provides high resistance to explosive bursting without the weight penalty of a uniformly thick design.
Solution Approach 2:
The shell provides localized reinforcement where needed for burst resistance, rather than uniformly increasing thickness throughout the entire container. This allows the container to achieve high strength-to-weight ratio by concentrating material where it provides maximum protective benefit.
3Reliability
If the container is subjected to high internal pressure to maintain beverage quality, then the pressure stability is improved, but the risk of explosive bursting increases
Solution Approach 1:
The shell acts as a pre-established safety barrier that cushions against explosive bursting before it can occur. When the container is damaged, the shell contains the pressurized gas and prevents catastrophic failure, allowing the container to safely maintain high internal pressure during normal operation.
Solution Approach 2:
The shell converts the harmful effect of pressurized gas (which could cause explosive bursting) into a beneficial safety feature. The same pressurized gas that maintains beverage quality also tests and validates the shell's protective capability, ensuring that any failure will be controlled and non-explosive.
4Strength
If the container is designed with a cardboard or HDPE shell for protection, then the burst strength is improved, but the design freedom and external features are limited
Solution Approach 1:
The shell can be manufactured in various configurations, thicknesses, and structural designs to meet different burst strength requirements while maintaining design freedom. The stretch blow-moulding process allows for flexible design parameters including integrated handles, spigots, and other external features that would be difficult to achieve with traditional cardboard or rigid HDPE shells.
Solution Approach 2:
The stretch blow-moulded polyester shell provides a flexible form factor that can be easily shaped and designed with various external features. Unlike rigid cardboard or thick HDPE, this shell material allows for integrated design elements such as handles, stacking features, and decorative elements while maintaining adequate burst protection.
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 container exhibits a significantly higher burst strength and reduced gas loss, maintaining pressure stability and beverage quality, even at elevated temperatures, and allows for safer handling and disposal by preventing explosive bursting and minimizing gas escape.
Implementation Method 1
the casing is enveloped by a stretch blow moulded polyester shell... the internal pressure urges the casing against the shell
Implementation Method 2
with embossing for enhanced puncture resistance and stability
Data Source
AI summary
A container for liquids, such as beverages and oils, may include a blow moulded polyester casing, a valve for dispensing the liquid from the container, and an inlet for introducing a propellant. The casing may be enveloped by a stretch blow moulded polyester shell.