Extracellular Polymers from Granular Sludge as Paper Sizing Agents

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Solution Overview

Problem

Conventional papermaking methods rely on expensive and environmentally damaging sizing chemicals to achieve water resistance, which are also in limited supply and not carbon-neutral.

Innovation Solution

Utilization of extracellular polymeric substances from granular sludge, specifically exopolysaccharides, as a sizing agent for paper, which are effective in providing water resistance without the need for further purification and can be obtained from wastewater treatment processes, reducing waste disposal costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional sizing chemicals (starches, rosin, alkyl ketene dimer) are used to achieve water resistance in paper, then the paper gains the required water resistance property, but the production cost increases and environmental damage occurs

Engineering Contradiction:

Improvewater resistanceVSAvoidenvironmental damage

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The invention converts waste sludge from wastewater treatment plants, which is normally a harmful environmental pollutant requiring costly disposal, into a beneficial sizing agent for paper. The extracellular polymeric substances in the sludge are utilized to provide water resistance to paper, thereby transforming an environmental problem into a valuable resource and eliminating disposal costs.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The invention utilizes substances that are already present in wastewater treatment sludge (extracellular polymeric substances with hydrophobic properties) to perform the sizing function. This self-service approach eliminates the need for separate sizing chemical production and application, reducing both cost and environmental impact while maintaining water resistance functionality.

Inventive Principle:

Principle #25Self-service

2Reliability

If conventional sizing chemicals are used to provide water resistance, then the paper achieves the required functionality, but the production cost increases due to expensive chemicals and disposal costs

Engineering Contradiction:

Improvewater resistanceVSAvoidproduction cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The invention replaces expensive conventional sizing chemicals with a free or low-cost alternative derived from waste sludge. The extracellular polymeric substances obtained from sludge provide effective water resistance at no additional material cost, and the process eliminates the need for purchasing and applying commercial sizing agents.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If conventional sizing chemicals are used, then water resistance is achieved, but the supply is limited and production is not carbon-neutral

Engineering Contradiction:

Improvewater resistanceVSAvoidavailability

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The invention utilizes extracellular polymeric substances from granular sludge that can be produced in large quantities through wastewater treatment processes. These substances serve multiple functions: they provide water resistance for paper sizing and simultaneously represent a scalable, sustainable resource that is not limited by the production constraints of conventional sizing chemicals.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Extracellular polymeric substances from granular sludge effectively enhance water resistance in paper, offering a cost-effective and environmentally friendly alternative to traditional sizing chemicals, with improved performance compared to known agents like alginate.

Implementation Method 1

These fibres contain hydroxyl groups. Hydrogen bonding between water molecules and the hydroxyl groups of the cellulose and/or hemicellulose fibres is energetically favourable

Methodology Applied

Scientific EffectHydrogen bonding:

Implementation Method 2

extracellular polymeric substances obtainable from granular sludge are suitable and effective for sizing paper... providing water resistance

Methodology Applied

Scientific EffectHydrophobic interaction:

Data Source

PatentUS9963829B2Extracellular polymers from granular sludge as sizing agents

Publication Date: 2018.05.08 HASKONING DHV NEDERLAND BV

AI summary

An invention in the field of papermaking that relates in particular to sizing paper. Problems with state of the art methods are that the sizing chemicals used are typically expensive; may be available only in limited supply; are produced using methods that are damaging to the environment; and whose production is far from carbon-neutral. It is an object of the present invention to provide an alternative to the methods of the prior art and to overcome one or more of the above mentioned disadvantages.