Semi-Corrugated Paperboard Panels With Cross-Flute Bond Lines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The corrugated industry faces challenges in reducing paper basis weights without compromising the structural integrity and strength of corrugated boxes, as lightweight liners and mediums are prone to failure in high-speed manufacturing processes, and there is a need for alternative designs to match packaging requirements beyond mere basis weight reductions.
Innovation Solution
The invention introduces semi corrugated board production through modified corrugating rolls with slots and creasing tools, allowing for flute formation in the cross-machine direction and creasing in the machine direction, eliminating the top liner and creating cross flute bond lines, which stabilize the fluted medium and enhance bonding with the bottom liner, resulting in panels with reduced fiber content and increased strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If paper basis weights are reduced to lower cost and reduce environmental impact, then fiber content and production cost decrease, but structural integrity and strength of corrugated boxes deteriorate
Solution Approach 1:
The invention segments the traditional 3-ply corrugated board structure into a 2-ply structure by eliminating the top liner. The fluted medium is creased in the machine direction to create self-supporting segments that maintain structural integrity without requiring a top liner, thereby reducing fiber content while preserving strength.
Solution Approach 2:
The invention introduces creasing in the machine direction (a new dimensional approach) to the traditional cross-machine fluting. This creates a grid-like structure with enhanced dimensional stability that maintains box strength with fewer plies, resolving the contradiction between reduced fiber content and maintained structural integrity.
2Quantity of substance
If very lightweight liners and mediums are used to reduce basis weight, then fiber consumption decreases, but the ability to withstand high-speed manufacturing process deteriorates
Solution Approach 1:
The fluted medium is creased in the machine direction before the top liner would normally be applied. This preliminary creasing action creates structural reinforcement that allows lightweight materials to withstand the stresses of high-speed manufacturing without compromising durability.
Solution Approach 2:
The invention creates a composite structure where the fluted medium with machine-direction creases forms a self-supporting framework. This composite approach using a single material with dual-directional structural features (fluting cross-machine + creasing machine-direction) replaces traditional multi-ply constructions, enabling lightweight yet durable packaging that survives high-speed manufacturing.
3Strength
If conventional corrugated board structures are used to ensure strength, then packaging requirements are met, but fiber content and production cost increase
Solution Approach 1:
The invention extracts and eliminates the top liner from the traditional 3-ply corrugated board structure. The fluted medium with machine-direction creases is sufficient to provide the necessary structural strength, allowing removal of the top liner and associated adhesive, thereby reducing fiber content and production cost while maintaining packaging strength.
Solution Approach 2:
The invention changes the structural parameters of the fluted medium by adding machine-direction creasing to the traditional cross-machine fluting. This parameter change creates a grid structure with enhanced stiffness and strength-to-weight ratio, enabling reduced fiber content while maintaining or improving packaging strength.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The semi corrugated board process enables the production of panels with up to 30% less fiber content while maintaining or enhancing strength, offering a range of products like 2-ply, 3-ply, and 5-ply panels that match various packaging needs, including doublewall and triplewall configurations, with improved flexural stiffness and resistance to compression.
Implementation Method 1
flutes are formed in the medium... It is these flutes that ultimately space apart the top and bottom liners to form corrugated board
Implementation Method 2
the fluted medium that is suitably attached to the liners by a starch based adhesive
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A means of making a multi ply structural panel by eliminating the top liner in the corrugating process. The present invention is made possible through modification to the corrugating rolls of the singlefacer. The design modification to the rolls involves incorporation of slots that run around the circumference of one roll and mating creasing tools incorporated around the circumference of the other of the corrugated roll set. These slots and creasing tools are incorporated across the existing flutes of the corrugating rolls.