Polymer-Flocculated Paper Filler for Strength Retention
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Solution Overview
Problem
The use of fillers in paper production leads to a disruptive loss of strength due to their higher content, which is not effectively addressed by existing methods, and there is a need for improved fillers that maintain paper properties without significant deterioration.
Innovation Solution
A method involving the use of an aqueous polymer dispersion mixed with a flocculant and then dispersed with a pigment in solid form, forming a polymer-pigment compound that maintains particle fineness and enhances filler properties, using polymers like polyvinyl acetate and organic polyelectrolytes as flocculants, and pigments such as kaolin, to create a stable paper filler.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If filler content is increased to save costs and improve optical properties, then manufacturing cost is reduced and optical properties are improved, but paper strength deteriorates
Solution Approach 1:
A polymer is introduced as an intermediary substance that binds filler particles together to form aggregates. These aggregates behave as larger units that maintain fiber-to-fiber bonding capacity while incorporating multiple filler particles, thus preserving paper strength despite high filler content. The polymer acts as a bridge between filler particles and the fiber network.
Solution Approach 2:
The invention creates a composite filler structure consisting of polymer-bound filler aggregates. This composite material combines the cost-effective filler with the strength-providing polymer, resulting in a hybrid filler system that delivers both economic benefits and mechanical performance. The composite structure allows filler particles to be held together in clusters that maintain porosity and bonding capability.
2Ease of manufacture
If filler content is increased to improve cost efficiency, then manufacturing cost is reduced, but paper strength deteriorates
Solution Approach 1:
The polymer serves as a mediator that enables the use of higher filler content without sacrificing strength. By binding filler particles into aggregates, the polymer allows the papermaker to increase filler loading for cost savings while the aggregate structure maintains the necessary bonding capacity for paper strength.
3Strength
If filler particles are aggregated to maintain strength, then paper strength is preserved, but particle size distribution changes
Solution Approach 1:
The filler aggregation is controlled to create a segmented structure where multiple fine filler particles are grouped into larger aggregates. This segmentation allows the filler to occupy space more efficiently while maintaining the fine particle characteristics for optical properties. The polymer binds these segmented units together in a controlled manner.
Solution Approach 2:
The invention changes the effective particle size parameter by creating aggregates from fine filler particles. The aggregates have a larger hydrodynamic radius and different packing behavior compared to individual particles, which affects retention and distribution in the paper web while maintaining the fine particle surface area for optical performance.
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
This method allows for increased filler content without significant strength loss, maintaining paper properties and enabling higher filler ratios, as demonstrated by the fixation of polymer on the filler surface and improved paper strength development.
Implementation Method 1
mixing the aqueous polymer dispersion with a flocculant to obtain a mixture
Implementation Method 2
dispersing a pigment in solid form in the mixture
Data Source
Figure 1
Figure 2~3
AI summary
A process for producing a paper filler comprising the steps of: a) providing an aqueous polymer dispersion; b) mixing the aqueous polymer dispersion with a flocculant to obtain a mixture; c) dispersing a pigment in solid form in the mixture.