Never-Dried Fibre Paper Dimensional Stability via Wet Strength Resin
Solution Overview
Problem
Paper and board products face dimensional instability due to moisture changes, which existing technologies have not adequately addressed, especially in products like wallpapers and gypsum boards that are sensitive to humidity and water exposure.
Innovation Solution
A process involving a fibre slurry with never-dried cellulose fibres treated with a strength composition comprising a permanent wet strength resin component, such as polyamidoamine-epihalohydrin resin, and a sizing agent, which improves tensile strength and hydrophobicity, reducing wet expansion by at least 10% compared to untreated products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If cellulose fibres are used in paper or board products, then the material is naturally available and easy to process, but the dimensional stability deteriorates due to moisture absorption and swelling
Solution Approach 1:
The patent applies composite materials by combining cellulose fibres with synthetic polymer particles (0.1-5 mm in size) to create a hybrid structure. The polymer particles are distributed throughout the fibre matrix, forming a composite material that leverages the natural properties of cellulose while adding the dimensional stability of synthetic polymers. This composite approach directly addresses the contradiction by maintaining the ease of manufacture with cellulose while improving dimensional stability through polymer reinforcement.
Solution Approach 2:
The patent applies parameter changes by modifying the physical and chemical parameters of the paper or board structure through the addition of polymer particles. The particles change the moisture absorption characteristics and structural rigidity parameters of the material, allowing it to maintain dimensional stability while retaining the base cellulose composition. This enables the material to resist swelling and shrinking that would normally occur with moisture changes.
2Stability of the object's composition
If fillers are added to increase dimensional stability, then the dimensional stability improves, but the fibre bonding and strength may deteriorate
Solution Approach 1:
The patent applies parameter changes by carefully controlling the size parameter of the added particles (0.1-5 mm range) and their concentration in the fibre slurry. This parameter optimization allows the particles to provide dimensional stability without excessively interfering with fibre-to-fibre bonding. The specific size range ensures particles are large enough to provide structural support but small enough to distribute evenly without creating weak points in the fibre network.
Solution Approach 2:
The patent applies local quality by having the polymer particles distributed throughout the fibre matrix rather than concentrated in specific areas. This uniform distribution ensures that dimensional stability is provided locally throughout the entire material structure, while maintaining consistent fibre bonding characteristics across the paper or board product. Each local region benefits from the dimensional stability of nearby particles without compromising the overall fibre network integrity.
3Strength
If fibres are highly refined to improve bonding, then the bonding between fibres improves, but the dimensional stability worsens due to increased moisture sensitivity
Solution Approach 1:
The patent applies composite materials by combining refined fibres with polymer particles that have different moisture response characteristics. The refined fibres provide excellent bonding and surface properties, while the polymer particles compensate for the increased moisture sensitivity by providing a stable structural framework that resists swelling and shrinking, thus maintaining dimensional stability despite the high refinement level.
Solution Approach 2:
The patent applies parameter changes by adjusting the refinement parameter of fibres to achieve optimal bonding while introducing polymer particles that modify the overall moisture response parameter of the material. This allows the system to maintain high fibre bonding from refinement while the polymer component adjusts the dimensional stability parameter to compensate for any negative effects of refinement on moisture sensitivity.
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 process enhances the dimensional stability and wet strength of paper and board products, reducing wet expansion and maintaining strength properties while minimizing energy consumption and process complexity.
Implementation Method 1
a strength composition comprising a permanent wet strength resin component, such as polyamidoamine-epihalohydrin resin, and a sizing agent, which improves tensile strength and hydrophobicity
Data Source
AI summary
The present invention relates to a process for producing a paper or a board product having increased dimension stability comprising providing a fibre slurry comprising never-dried fibres, treating the fibre slurry with a strength composition, and forming a paper or a board product from the treated fibre slurry, wherein the strength composition comprises a permanent wet strength resin component and a sizing agent. The present invention further relates to a use of a strength composition for increasing dimensional stability of a paper and a board, and to a paper or a board product having improved dimensional stability.