1. Field of the Invention
The present invention relates to containers for frangible articles and, more particularly but not exclusively, to containers formed by vacuum-forming and used as egg boxes.
2. Background Art
It is known in the art to obtain trays by thermoforming techniques, especially vacuum-molding, and to stack them one into the other. It is also known to use such trays to define containers for frangible articles, such as egg box (see Applicant's Canadian Patent No. 2,028,229).
These manufacturing techniques produce cost-efficient containers that are often recyclable and stackable in opened positions so as to require little storage space. Moreover, the containers resulting from such manufacturing techniques are advantageously transparent/translucent, such that a consumer may view the frangible contents of the container without having to open the container. Whether the frangible articles be colored eggs from Auracana hens, hand-picked tomatoes or the like, the plastic sheet containers allow the product to be exposed, while providing some form of shielding against impacts and tampering.
As such containers are made of thin sheets of plastic, the geometry of these containers must be defined so as to provide suitable structural integrity to the container taking into account the manipulations the container goes through.
The containers accommodating these contents must often be stacked one on another in refrigerated cabinets of food markets. For instance, when such containers are used as egg boxes of large size, it appears that containers supporting the weight of other filled containers may not present a sufficient level of rigidity to prevent deformation. More specifically, containers have been known to collapse at their corners.
Moreover, as they are conveyed on automated production lines and equipment, these containers often sustain lateral pressure that may damage their corners. As damage to the frangible articles results in major inconveniences (e.g., loss of profitability, maintenance required to clean up, waste of products), it is desirable to improve the structural integrity of the containers for frangible articles.