Egg Carton Mating Cell and Lid Post Structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing egg cartons, both pulp and plastic, face issues with dimensional stability and egg protection due to mechanical forces and environmental changes during handling and transport, leading to egg breakage and handling difficulties.
Innovation Solution
A plastic egg carton design featuring mating cell and lid posts with planar ramp surfaces that increase compressive strength and resistance to side impacts, allowing for better egg protection and alignment, while maintaining a standard footprint to accommodate larger eggs without increasing carton size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If flexible walls are used between cell pockets to protect eggs, then egg protection is improved, but the carton becomes vulnerable to compressive and lateral impact forces during handling and stacking
Solution Approach 1:
The carton structure is segmented into rigid cell pockets formed by vertical partitions, with each cell containing an egg. The flexible membrane is segmented to fit within each cell rather than forming continuous walls between cells, allowing each cell to be independently protected while maintaining overall structural integrity.
Solution Approach 2:
The carton combines rigid plastic material for the cell pockets and partitions with a flexible membrane material for the cell interiors. This composite structure provides both the rigidity needed to resist impact forces and the flexibility needed to protect eggs from direct contact with rigid surfaces.
2Strength
If pulp cartons are used to provide stiffness when dry, then structural rigidity is improved, but the cartons become soggy and lose dimensional stability when exposed to humidity changes
Solution Approach 1:
The material parameter is changed from pulp (paper-based) to plastic, which fundamentally alters the material's response to humidity. Plastic maintains consistent dimensional properties across varying humidity conditions, eliminating the soggy problem while preserving structural rigidity through the molded cell pocket design.
3Strength
If stiff locking flaps and hinges are used in pulp cartons to provide secure closure, then closing strength is improved, but the lid does not line up with the base tray resulting in improper carton level
Solution Approach 1:
The hinge is designed with controlled flexibility rather than complete rigidity. The hinge allows for slight movement and adjustment during the closing process, enabling the lid to self-align with the base tray. This dynamic flexibility compensates for manufacturing tolerances while still providing secure closure through the locking mechanism.
Solution Approach 2:
The locking flaps are positioned and sized to engage with corresponding features on the base tray before final closure is complete. This preliminary engagement guides the lid into proper alignment with the base tray, ensuring that the carton closes level and square.
Data Source
AI summary
Plastic egg cartons having mating cell and lid posts for improved egg protection. The carton has a base tray and hinged lid, the tray including a plurality of cells for receiving individual eggs, and the tray having a plurality of cell posts each formed at an intersection of four adjacent cells as an extension of the sidewalls of the four adjacent cells. Preferable, each cell post has four generally planar ramp surfaces, one disposed respectively on each of the four sidewall extensions. The lid has a plurality of lid posts for mating with the cell posts when the lid is in a closed position.