Cardboard Tray Locking Mechanism for Adhesive-Free Strength
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Solution Overview
Problem
Existing cardboard trays require additional mechanical or chemical means, such as tacks and adhesives, to maintain strength, which is undesirable for recycling, environmental impact, and cost efficiency.
Innovation Solution
A cardboard tray design featuring a locking mechanism with uninterrupted flanges formed by a locking sheet portion and locking opening, allowing flange parts to connect without adhesives, ensuring strength and enabling closure with a foil.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If additional means like tacks, strings, or adhesives are used to ensure sufficient strength of the cardboard tray, then the strength is improved, but the recycling efficiency and cost efficiency deteriorate
Solution Approach 1:
The flange parts are divided into neighboring segments that are connected through a locking mechanism. The locking sheet portion and locking opening create discrete connection points between flange segments, allowing the tray to maintain strength through distributed structural connections rather than continuous adhesive bonding, thereby improving recyclability and cost efficiency.
Solution Approach 2:
The locking mechanism is self-forming through the interaction of the locking sheet portion and locking opening during the folding process. The structure itself creates the connection without requiring external adhesives or mechanical fasteners, achieving both strength and ease of manufacture/recycling.
2Strength
If a locking mechanism with uninterrupted flanges is used to connect neighbouring flange parts, then the strength is improved and material waste is reduced, but the device complexity increases
Solution Approach 1:
The locking sheet portion and locking opening are integrated into the same continuous sheet of cardboard from which the tray is formed. This merging of the locking mechanism components with the tray structure itself eliminates the need for separate fastening parts, reducing device complexity while maintaining strength and reducing material waste.
Solution Approach 2:
The locking mechanism utilizes the third dimension by having the locking sheet portion extend through the locking opening in the perpendicular flange part. This vertical through-connection creates a three-dimensional interlocking structure that provides strength without requiring complex lateral connections or additional components.
3Adaptability or versatility
If the uninterrupted flange is directed away from the receiving space to provide closure area, then the ability to close the tray is improved, but the access to the receiving space is reduced
Solution Approach 1:
The flange is segmented into multiple neighboring parts that are distributed around the circumference of the tray. This segmentation allows the closure function to be distributed across multiple points rather than requiring a single large flange, thereby maintaining closure capability while minimizing the impact on the receiving space opening.
Solution Approach 2:
The locking sheet portion extends only partially through the locking opening, creating a form-fit connection that provides sufficient strength without requiring the flange to occupy excessive space. This partial action achieves the necessary closure function while minimizing interference with the receiving space.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A cardboard tray (1, 101, 201) folded from a sheet of cardboard (301, 401, 501), an assembly of a cardboard tray and a foil and a sheet of cardboard arranged for being folded into a cardboard tray, wherein said cardboard tray comprises sheet portions defining a bottom wall (3) and side walls (5) defining a receiving space (2) of said cardboard tray, said side walls being connected, via respective first folding lines (7), to said bottom wall, wherein said cardboard tray further comprises flange parts (9, 11) connected, via respective second folding lines (13), to said side walls at a side of said side walls facing away from said bottom wall, wherein neighbouring flange parts of said flange parts are connected to each other via a locking sheet portion (15) of one of said neighbouring flange parts, wherein said locking sheet portion is connected, via a third folding line (17), to said one of said neighbouring flange parts and extends at least partly through a locking opening (19) provided in said sheet of cardboard, which locking opening is preferably provided in the other of said neighbouring flange parts, for said connecting of said neighbouring flange parts and realizing an uninterrupted flange (21) along a circumference of said cardboard tray.