Corrugated Board Folding Structure for Stable Sharp Corners
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Solution Overview
Problem
The existing folding structures of corrugated cardboard suffer from springback and unstable corner shapes due to compression of the liner on the inner surface, leading to meandering ridges and arc-shaped apexes, making it difficult to maintain corners in a stable folded state.
Innovation Solution
A folding structure for corrugated cardboard comprising a first liner, a second liner, and a core, with a decorative sheet on the first liner, featuring a cutout portion with oblique sides and a recessed groove or cut line configuration that stabilizes the corner by reducing springback and meandering, using a recessed groove or cut line to control the folding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the corrugated cardboard is folded so that groove wall parts are brought into contact with each other to form a corner, then the corner structure is formed, but springback occurs and the corner shape becomes unstable with meandering ridges and arc-shaped apexes
Solution Approach 1:
A recessed groove is formed in advance at the bottom portion of the cutout portion before folding. This preliminary structural preparation guides the folding process and prevents springback by providing a predetermined path for the liner to follow during corner formation, ensuring stable and sharp corner apexes.
Solution Approach 2:
The bottom portion of the cutout portion is segmented by introducing a recessed groove that divides the structure into distinct regions. This segmentation allows the liner to fold along a controlled path rather than compressing uniformly, preventing meandering ridges and stabilizing the corner shape.
2Shape
If the liner is compressed on the inner surface side to form a corner, then the corner is formed, but the ridge shape becomes disordered and meandering
Solution Approach 1:
The recessed groove is formed in advance at the bottom portion of the cutout portion to establish a predetermined folding path. This preliminary action ensures that the liner follows a straight trajectory during folding, preventing meandering ridges and ensuring manufacturing precision of the corner shape.
Solution Approach 2:
The recessed groove modifies the geometric parameters of the cutout portion by creating a controlled depression at the bottom. This parameter change provides a physical guide that constrains the folding process, ensuring that the ridge forms straight rather than meandering.
3Shape
If the corrugated cardboard is folded to form a corner, then the corner structure is created, but the apex becomes arc-shaped without sharpness
Solution Approach 1:
A recessed groove is formed in advance at the bottom portion of the cutout portion to establish a sharp folding point. This preliminary structural feature ensures that the apex forms with precision and sharpness rather than becoming arc-shaped, as the groove provides a defined vertex for the corner.
Solution Approach 2:
The recessed groove changes the geometric parameters of the folding region by creating a controlled depression that concentrates the fold at a specific point. This parameter modification ensures sharp apex formation by preventing the liner from spreading out into an arc shape during folding.
Data Source
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AI summary
A folding structure of a corrugated cardboard including a first liner, a second liner, and a core interposed between the first liner and the second liner. A decorative sheet is attached to an outer surface of the first liner, the corrugated cardboard is formed with a cutout portion. A recessed groove or a cut line portion disposed along an extending direction of the cutout portion is provided on an opposite side of a surface of the first liner where the decorative sheet is provided, the recessed groove or the cut line portion is provided at a bottom portion of the cutout portion including the first oblique side portion and the second oblique side portion.