Fold-Flat Wedge Container With Hinged Leak-Proof Side Walls

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Solution Overview

Problem

The use of plastic packaging for wedge-shaped products, such as cheese, is undesirable from an environmental standpoint, despite its effectiveness in sealing and allowing controlled gas exchange, and existing paper-based packaging methods lack flexibility and ease of assembly.

Innovation Solution

A method for producing a container using a laminate of card and film, where the bonding between container halves occurs along an unsupported film flap, allowing for asymmetrical folding and hinging of side walls, and a continuous film surface to prevent leakage, enabling easy assembly and hermetic or controlled gas flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If plastic packaging is used for wedge-shaped products, then sealing effectiveness and gas control are improved, but environmental harm increases

Engineering Contradiction:
Improvesealing effectivenessVSAvoidenvironmental harm
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention changes the material parameter from plastic to a laminate structure of paperboard and plastic film, maintaining the sealing functionality while reducing environmental impact. The plastic film layer preserves the gas control and sealing properties, while the paperboard outer layer reduces overall plastic usage and environmental harm.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The packaging uses a composite laminate structure combining paperboard and plastic film layers. This composite material approach allows the plastic film to provide necessary sealing and gas control functions while the paperboard provides structural support and reduces the total amount of plastic required, thus maintaining reliability while reducing environmental harm.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If card-based packaging is used instead of plastic, then environmental harm is reduced, but flexibility and ease of assembly deteriorate

Engineering Contradiction:
Improveenvironmental harmVSAvoidease of assembly
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The laminate structure combines paperboard with plastic film, where the plastic film provides flexibility and ease of assembly similar to pure plastic packaging, while the paperboard layer reduces environmental harm. The bonding between layers creates a unified structure that maintains both environmental benefits and operational flexibility.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The packaging applies different material properties to different regions: the outer paperboard layer provides structural rigidity and environmental benefits, while the inner plastic film layer provides flexibility and ease of assembly where needed. This local differentiation of material qualities resolves the contradiction between environmental harm and ease of assembly.

Inventive Principle:
Principle #3Local quality

3Strength

If bonding occurs between laminated regions, then structural strength is improved, but ability to pivot from fold-flat configuration deteriorates

Engineering Contradiction:
Improvestructural strengthVSAvoidability to pivot
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The bonding is segmented to occur only at specific locations (side walls and apex) rather than across the entire structure. This allows the base and other regions to remain unbonded and flexible, enabling easy pivoting from the fold-flat configuration while still providing structural strength at the critical bonded joints.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bonding is applied locally at specific regions (side walls and apex) rather than uniformly across the entire container. This local bonding provides structural strength where needed while leaving other regions unbonded and flexible, allowing easy pivoting from the fold-flat configuration.

Inventive Principle:
Principle #3Local quality

4Adaptability or versatility

If asymmetrical folding is implemented, then container versatility is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvecontainer versatilityVSAvoidmanufacturing complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The container design employs asymmetrical folding patterns that allow the same blank to produce different container configurations (wedge-shaped, tray-like, sandwich containers). This asymmetry provides versatility in container shapes while the underlying laminated structure and bonding method remain consistent, limiting the increase in manufacturing complexity.

Inventive Principle:
Principle #4Asymmetry

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 method results in a flexible, leak-proof container that can be easily assembled and filled, reducing plastic use while maintaining effective sealing and gas control, suitable for various product shapes and sizes.

Implementation Method 1

The bonding between the two halves of the container along a side wall takes place between a flap of film which is not supported with underlying card. This creates a free edge of card adjacent to the flap of film thereby creating a region along the side wall about which the container can readily pivot from the fold-flat configuration.

Methodology Applied
Scientific EffectSealing:

Implementation Method 2

A method for producing a container using a laminate of card and film

Methodology Applied
Scientific EffectLamination: Lamination

Data Source

PatentEP4361057B1Method for forming a container in a fold flat configuration
Publication Date: 2025.12.03 PROAMPAC HOLDINGS INC
  • EP4361057B1 patent drawingFigure 1
  • EP4361057B1 patent drawingFigure 2~3
  • EP4361057B1 patent drawingFigure 4A

AI summary

A wedge shaped container formed from a folded web of flexible material. The container comprises a base 1, a rear wall 2 connected to the base, and a pair of upstanding side walls decreasing in height from the rear wall to the opposite end of the base. Each side wall is formed of two side wall panels 4,6 connected at an edge of the base and connected by a hinge joint. From a fold-flat configuration, folding of the rear wall 2 away from the base 1 causes the side wall panels 4,6 to be folded inwardly into the erected configuration. The container may have an integral lid 8. The invention also extends to a method of making a blank using a sequence of cuts to create unsupported file regions.