Modified Kaolin Stickies Removal in Paper Recycling
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Solution Overview
Problem
Current methods for removing stickies from waste paper and paperboard are inefficient, often requiring additional chemicals and are limited to specific recycling processes like flotation, leading to operational disruptions and product quality issues.
Innovation Solution
A modified kaolin-based composition is developed by dispersing kaolin clay with chemical dispersants, treating the particles with modifying reagents, and blending them with a surfactant to enhance stickies separation, suitable for various recycling processes including washing, flotation, and centrifugal cleaning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current stickies control methods (passivation, dispersion, fixation, detackification) are used, then the effect of stickies on paper machine and final product is minimized, but additional chemicals, polymers, dispersants or additives are required at additional production cost
Solution Approach 1:
The invention extracts and removes stickies from the paper pulp through flotation deinking processes, rather than merely controlling or masking their effects. The modified kaolin acts as a collector that attaches to stickies, enabling their physical removal from the system through froth flotation, thereby eliminating the need for additional chemical additives required by conventional control methods
Solution Approach 2:
The kaolin is modified through surface treatment with hydrophobizing agents, changing its surface properties from hydrophilic to hydrophobic. This parameter change enables the kaolin to attach to stickies and be carried to the froth phase during flotation, transforming it from an ineffective filler into an active stickies removal agent
2Productivity
If Pohlen method using hydrophobized mineral is used for stickies removal, then stickies are removed together with ink and dirt particles during flotation deinking, but the method only works in recycling operations that use flotation
Solution Approach 1:
The modified kaolin composition is designed to be universally applicable across multiple recycling process types. While primarily effective in flotation deinking operations where it excels at stickies removal, the modified mineral can also be used in non-flotation processes such as washing and screening, making it a versatile solution for various paper recycling operations regardless of the specific contamination removal mechanism employed
3Productivity
If Curtis method using cationic kaolin is used for stickies removal, then stickies or ink are removed using centrifugal cleaner due to higher specific gravity, but the presence of cationic polymers significantly affects the wet end part of papermaking and is detrimental to fiber separation
Solution Approach 1:
The invention uses modified kaolin particles as a temporary, disposable collecting agent that attaches to stickies for removal. The kaolin serves its purpose during the stickies removal process and is then discarded with the removed contaminants in the froth phase or waste stream, eliminating the need for expensive, problematic cationic polymers that require careful management and can cause ongoing issues in papermaking operations
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 modified kaolin-based composition effectively agglomerates and separates stickies from fibers, improving removal efficiency and reducing operational downtime and production costs by using a broader range of recycling processes without additional chemicals.
Implementation Method 1
The modified kaolin-based particles are then blended with a surfactant to produce a stickies removal composition that improves the separation of the stickies from the waste paper and paperboard fibers
Implementation Method 2
The modified kaolin-based particles are then blended with a surfactant to produce a stickies removal composition that improves the separation of the stickies from the waste paper and paperboard fibers
Implementation Method 3
The cationic kaolin is prepared from anionic kaolin and a cationic polymer, such as epicholorohydrin polymer, poly(dialkyldiallylammonium halide), poly(diallydimethylammonium chloride) or polyalkylester of a tertiary amine halide. However, the presence of cationic polymers significantly affects the wet end part of papermaking
Implementation Method 4
U.S. Pat. No. 6,210,526 (to Pohlen) discloses a method of inhibiting and eliminating stickies from wastepaper through the addition of hydrophobized synthetic or natural mineral to a waste paper pulp wherein the stickies are removed together with the ink and dirt particles during flotation deinking
Data Source
AI summary
Removal of stickies from waste paper and paperboard is obtained with the use of a modified kaolin-based stickies removal composition. The modified kaolin-based stickies removal composition is produced by modifying the kaolin clay, separating the modified kaolin clay from the non-reactive kaolin clay, and then adding a nonionic surfactant to the modified kaolin-based particles. Removal of stickies is improved by the use of this modified kaolin-based stickies removal composition during the recycling of the waste paper and paperboard.