Packaging Board Sizing for Raw Edge Liquid Penetration Resistance
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Solution Overview
Problem
Current packaging boards face challenges with raw edge penetration from liquids and moisture during sterilization and filling processes, requiring complex pH control and multiple board grades for different applications, which is inefficient and prone to manufacturing issues.
Innovation Solution
A packaging board is developed using a combination of alkyl ketene dimer (AKD) size, stearic acid anhydride, wet-strength size, and an aluminium compound, which provides resistance to various liquids and thermal treatments without requiring pH adjustments, allowing for a single board grade to be used across multiple applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If dual sizing with rosin size and AKD size is used to achieve resistance to peroxides and lactic acid, then the packaging board can withstand different liquids, but the manufacturing process becomes complex with difficult pH control and risk of precipitation
Solution Approach 1:
The patent combines multiple sizing agents (AKD, ASA, and alum) into a single sizing system that can be applied under uniform alkaline conditions, eliminating the need for separate acidic and neutral sizing stages. This merging of functions allows the board to resist both peroxides and lactic acid without complex pH control
Solution Approach 2:
The sizing system uses alum as a universal mordant that works with both AKD and ASA under alkaline conditions, creating a multi-functional approach where a single pH regime supports multiple sizing mechanisms simultaneously, reducing manufacturing complexity while maintaining versatility
2Reliability
If multiple board grades are produced for different applications, then specific liquid resistance can be achieved, but production efficiency decreases and costs increase
Solution Approach 1:
The patent creates a universal board grade using a combination of AKD, ASA, and alum sizing that simultaneously provides resistance to peroxides, lactic acid, and other liquids. This single multi-functional board replaces the need for multiple specialized grades, increasing production efficiency while maintaining reliable performance across different applications
3Adaptability or versatility
If AKD size is used alone for dairy product packaging, then lactic acid resistance is achieved, but peroxide sterilization resistance is lost
Solution Approach 1:
The patent merges AKD sizing with ASA and alum sizing in a coordinated system where ASA provides peroxide resistance and AKD provides lactic acid resistance, with alum acting as a binding agent for both. This combined approach ensures both resistance properties are achieved simultaneously in a single sizing process
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 solution effectively prevents raw edge penetration in a wide range of conditions, including autoclaving and exposure to detergents, strong alcohols, and dairy products, while simplifying manufacturing and reducing costs by eliminating the need for pH control and allowing for larger-scale production with increased product purity.
Implementation Method 1
The fibrous base is sized with a combination of an alkyl ketene dimer (AKD) size, stearic acid anhydride
Implementation Method 2
wet-strength size and an aluminium compound, which provides resistance to various liquids and thermal treatments
Implementation Method 3
sized with a combination of an alkyl ketene dimer (AKD) size, stearic acid anhydride, wet-strength size and an aluminium compound
Implementation Method 4
An inner cutting edge (raw edge) of the board is exposed to liquid or moist products contained in a container, such as a disposable drinking cup, or a package, such as a milk or juice carton, so that the liquid has the possibility to get absorbed into the fibrous board base through this edge (raw edge penetration)
Data Source
AI summary
The invention relates to a packaging board comprising a fibrous base and one or more polymer coating layers on one or both sides of the fibrous base. According to the invention the fibrous base contains the combination of an alkyl ketene dimer size, stearic acid anhydride, a wet-strength size and an aluminium compound, which give the board resistance to aggressive liquids as well as thermal treatment, particularly an improved resistance to raw edge penetration in such circumstances. The invention further relates to containers and packages made of the board, for instance disposable drinking cups, dairy product cartons and auto-clave packages, as well as use of the board for such purposes.