Paper Surface Treatment with Water-Swellable Polymer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for enhancing the mechanical strength of paper by using starch as a binding agent face challenges due to harsh drying conditions, which prevent starch granules from gelatinizing, leading to inadequate adhesive force and mechanical properties.
Innovation Solution
A method involving the application of a mixture comprising a polysaccharide and an aqueous dispersion of anionic water-swellable polymer particles, along with mineral or organic salts, to create a resilient environment for starch granules, improving gelatinization and mechanical strength under drastic drying conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a harsh drying profile is used to remove water quickly, then productivity is improved, but the starch granules fail to gelatinize and mechanical strength deteriorates
Solution Approach 1:
The patent introduces polyacrylamide polymer as an intermediary substance that mediates between the harsh drying conditions and the starch granules. The polymer creates a protective environment that allows starch to gelatinize even under rapid drying conditions, enabling both high productivity and maintained mechanical strength
Solution Approach 2:
The patent changes the chemical parameters of the drying environment by adding polyacrylamide polymer to the starch suspension. This modification alters the drying dynamics and starch gelatinization behavior, allowing the system to withstand harsher drying profiles while maintaining product quality
2Force
If aqueous starch solution is used as binding agent, then adhesive force is improved, but COD increases and mould/bacteria formation occurs
Solution Approach 1:
The patent changes the chemical composition parameters by replacing part of the aqueous starch solution with polyacrylamide polymer. This substitution reduces the organic load (COD) and eliminates the substrate for mould and bacteria growth while maintaining the necessary adhesive properties through the polymer's binding capabilities
Solution Approach 2:
The patent creates a composite binding system combining starch and polyacrylamide polymer in a single suspension. This composite material leverages the adhesive properties of starch while the polymer component reduces harmful effects, achieving a synergistic effect that addresses both adhesion and environmental concerns
3Productivity
If spray nozzles are used to deposit starch suspension, then application efficiency is improved, but heavy maintenance is required
Solution Approach 1:
The patent modifies the physical parameters of the starch suspension by adding polyacrylamide polymer, which improves the flow and deposition characteristics of the suspension. This allows for more efficient spray application with reduced clogging and better atomization, thereby decreasing maintenance frequency
Solution Approach 2:
The patent formulation allows for the use of simpler, more durable spray nozzle designs that can handle the modified suspension better. The polyacrylamide-modified suspension is less prone to causing nozzle wear and clogging, effectively extending nozzle life and reducing maintenance costs
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 method significantly enhances the mechanical strength of paper by maintaining a moist atmosphere for starch granules, leading to improved adhesive force and resistance against delamination, even under harsh drying conditions.
Implementation Method 1
the water-retaining capacity of the water-swellable polymer imparts a moist atmosphere to the starch granules
Implementation Method 2
Starch granules require a high temperature, water and time to «burst/explode» to achieve gelatinization of the starch
Data Source
AI summary
This method for treating the surface of paper and/or one of the layers thereof, comprises the following successive steps:i) Supplying an aqueous suspension S of polysaccharide;ii) Supplying an aqueous dispersion D comprising (a) particles of at least one anionic water-swellable polymer P and (b) at least one compound selected from a mineral salt, an organic salt, an organic dispersing polymer and the mixtures thereof;iii) Mixing the suspension S and the dispersion D to obtain a mixture M;iv) Applying the mixture M to the surface of the paper and/or to at least one of the layers thereof.