Polymer Additive for Paper Dry Strength and Recycling
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Solution Overview
Problem
Current methods for producing paper or cardboard often result in reduced dry strength due to deteriorating fibre quality from increased recycling rates and the use of inexpensive raw materials, which also leads to issues with water circuits in papermaking machines being decommissioned.
Innovation Solution
A method involving radical polymerization of monomers to create a starting polymer, followed by hydrolysis to form a final polymer A, which is then added to an aqueous fibrous material suspension and dewatered on a water-permeable substrate to produce paper or cardboard with improved dry strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If recycling rates of waste paper are increased, then raw material costs are reduced, but fibre quality deteriorates leading to reduced dry strength
Solution Approach 1:
The patent changes the chemical parameters of the polymer additive by controlling the ratio of amino groups to carboxyl groups (between 0.9:1 and 1.1:1) and adjusting the molecular weight and composition of the polymer to optimize its binding capability. This allows the polymer to effectively bind deteriorating fibres from recycled paper while maintaining good dry strength properties.
Solution Approach 2:
The patent uses a composite polymer additive containing both amino groups and carboxyl groups in specific ratios, combined with recycled fibrous material. This composite approach creates a synergistic effect where the polymer bridges and binds the deteriorating fibres together, maintaining structural integrity while using recycled materials.
2Quantity of substance
If grammage of paper or cardboard is reduced to save raw material, then material costs are reduced, but dry strength deteriorates
Solution Approach 1:
The patent optimizes the polymer parameters including the amino to carboxyl group ratio (0.9:1 to 1.1:1), molecular weight (10,000 to 1,000,000 g/mol), and composition to maximize binding efficiency. This allows achieving good dry strength even at reduced grammage levels by improving the binding capability per unit mass.
Solution Approach 2:
The patent creates a functional copy or replacement for the mechanical strength that would normally come from higher grammage or better fibre quality. The polymer additive performs the binding function that would otherwise require more material mass, allowing reduced grammage while maintaining strength.
3Loss of energy
If water circuits in papermaking machines are decommissioned, then energy consumption is reduced, but dewatering efficiency and fibre quality are affected
Solution Approach 1:
The patent adjusts the polymer parameters including amino to carboxyl group ratio and molecular weight to optimize its performance in low-water environments. The polymer maintains effective binding and dewatering capability even when water circuits are reduced or decommissioned, ensuring reliable operation with lower energy consumption.
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 enhances the dry strength of the final paper or cardboard product while allowing for industrial-scale production, maintaining or improving fibre quality and reducing material costs.
Implementation Method 1
hydrolysing the starting polymer V in order to obtain the final polymer A, wherein the N-C(═O)R1 groups of formula (I) of the monomers (i) polymerised into the starting polymer V hydrolyse at least in part and in so doing form primary amino groups
Implementation Method 2
adding a final polymer A to a first aqueous fibrous material suspension, whereby a second aquesous fibrous material suspension containing final polymer A is created
Implementation Method 3
dewatering the second aqueous fibrous material suspension containing final polymer A on a water-permeable substrate to form a wet paper structure
Implementation Method 4
dewatering the wet paper structure, whereby the paper or the cardboard is formed
Data Source
AI summary
Methods for producing paper or cardboard are provided that comprise the steps(A) adding a final polymer A to a first aqueous fibrous material suspension, whereby a second aqueous fibrous material suspension containing final polymer A is created,wherein the final polymer A is obtainable byradical polymerisation of the monomers (i), (ii), (iii), (iv), and (v) as described herein in the amounts provided herein; andhydrolysing the starting polymer V in order to obtain the final polymer A,(B) dewatering the second aqueous fibrous material suspension containing final polymer A on a water-permeable substrate to form a wet paper structure,(C) dewatering the wet paper structure, whereby the paper or the cardboard is formed.