Moulded Pulp Egg Carton Side Edges That Prevent Unintended Opening

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Solution Overview

Problem

Conventional packaging units for products like eggs, such as egg cases, experience issues with the cover part moving relative to the bottom part due to handling forces, leading to unintended opening, which can cause product damage, packaging unit damage, and operational disruptions in automated packing lines, especially in flapless designs.

Innovation Solution

A packaging unit with a moulded pulp material featuring a self-aligning element on the side edges of the cover and bottom parts, which enhances the alignment and stability of the cover relative to the bottom, preventing unintended opening and improving strength and stability during handling, transport, and storage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the packaging unit uses a hinge connection for the cover part, then the packaging unit can be opened and closed, but the cover part may move relatively to the bottom part under handling forces, causing unintended opening

Engineering Contradiction:
Improveopening and closing functionalityVSAvoidstability during handling
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The side edge is divided into a first side edge portion and a second side edge portion separated by a recess. The first portion engages with the second portion of the opposite side edge to form a self-aligning element, creating a segmented structure that provides both opening/closing functionality and stability during handling.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The recess creates an asymmetric structure in the side edge, where one portion of the side edge extends further than the other. This asymmetry enables the self-aligning mechanism that prevents relative movement between cover and bottom parts while maintaining the hinge connection for opening and closing.

Inventive Principle:
Principle #4Asymmetry

2Reliability

If the packaging unit uses a lock mechanism, then the cover and bottom parts can be locked in closed position, but the lock may disengage under handling forces, causing unintended opening

Engineering Contradiction:
Improvelocking functionalityVSAvoidlock mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The self-aligning element is integrated into the side edge structure itself, merging the alignment function with the structural components. This eliminates the need for separate complex lock mechanisms while maintaining reliable locking through the engagement of the first and second side edge portions.

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If the packaging unit is designed as flapless, then the structure is simpler, but the cover part is more prone to moving forward relative to the bottom part, causing unlocking

Engineering Contradiction:
Improvestructural simplicityVSAvoidresistance to unintended opening
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The self-aligning element extends in the longitudinal direction of the packaging unit, adding a dimensional feature to the side edge. This longitudinal extension creates the first and second side edge portions that engage with each other, providing stability in the horizontal direction while maintaining the simple flapless design.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP4678563A2Packaging unit from a moulded pulp material with a self-aligning element and method for manufacturing such packaging unit
Publication Date: 2026.01.14 HUHTAMAKI MOLDED FIBER TECH
  • EP4678563A2 patent drawingFigure 1
  • EP4678563A2 patent drawingFigure 2
  • EP4678563A2 patent drawingFigure 3A~3B

AI summary

The present invention relates to a packaging unit from a moulded pulp material, a method for packing products, and a method for manufacturing such packaging units. The packaging unit comprises: - a bottom part with product receiving compartments for holding respective products, with the bottom part at least having a bottom front, a bottom surface, and two bottom sides; - a cover part at least having a cover front, a cover top, and two cover sides; - a hinge-element for hingedly connecting the cover and bottom parts; and - a lock for locking the bottom and cover parts in a closed position of the packaging unit, and wherein the bottom side and cover side comprise a side edge having a self-aligning element.