ASA Emulsion Rotor-Stator Mixing for Stable Particle Size

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Solution Overview

Problem

The existing process for manufacturing an emulsion of alkenyl succinic anhydride (ASA) in an aqueous solution of cationic starchy material results in unstable particle size distribution, leading to clogging issues in paper machine operations, which disrupts production and affects the quality of the final product.

Innovation Solution

A process involving the production of an ASA emulsion using an emulsification unit with a rotor/stator pair, where ASA and the aqueous solution of cationic starchy material are introduced separately into the emulsification chamber, and the emulsion is diluted downstream to increase fluid velocity and prevent clogging, utilizing separate inlets and a dilution device to maintain a stable particle size distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the emulsion is manufactured without a recirculation loop, then the manufacturing process is simpler and more efficient, but the particle size distribution becomes unstable leading to clogging

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidparticle size distribution stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-diluting the emulsion immediately after manufacturing in a single-pass process. The dilution step is built into the manufacturing flow before the emulsion enters the recirculation loop, ensuring particle size stabilization occurs proactively rather than reactively. This preliminary dilution prevents particle aggregation that would otherwise occur during subsequent handling and recirculation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces water as an intermediary substance to stabilize the emulsion. By adding water as a diluent in the dilution device, the system mediates between the manufacturing process and the recirculation loop, ensuring particle size remains stable without requiring the emulsion to recirculate back through the emulsification chamber.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If the emulsion particle size is reduced to improve bonding effectiveness, then hydrophobization properties improve, but clogging in transport pipes increases

Engineering Contradiction:
Improveparticle size controlVSAvoidclogging in transport pipes
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by controlling the dilution ratio and flow rate parameters in the dilution device. By adjusting these parameters, the system optimizes the balance between particle size distribution (for bonding effectiveness) and fluid velocity (to prevent clogging). The dilution modifies the emulsion's physical parameters to achieve both fine particle distribution and adequate flow characteristics.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses hydraulic principles by increasing fluid velocity through dilution to prevent clogging. The dilution device creates a higher flow velocity in the transport pipes, using the kinetic energy of the diluted emulsion to keep particles suspended and prevent deposition, thereby eliminating clogging while maintaining fine particle size distribution.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Reliability

If the emulsion is diluted to stabilize particle size distribution, then clogging is prevented, but the concentration of bonding agent decreases

Engineering Contradiction:
Improveparticle size distribution stabilityVSAvoidbonding agent concentration
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies partial action by implementing dilution to the extent necessary for stabilization without excessive dilution that would compromise bonding effectiveness. The dilution ratio is carefully controlled to provide just enough stabilization of particle size distribution while maintaining sufficient concentration of the bonding agent for effective hydrophobization of the paper substrate.

Inventive Principle:
Principle #16Partial or excessive action

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 process stabilizes the particle size distribution of the ASA emulsion, preventing clogging and ensuring continuous operation of the paper machine while maintaining the emulsion's effectiveness as a bonding agent.

Implementation Method 1

emulsification unit with a rotor/stator pair... mixing the ASA and the aqueous solution of cationic starchy material resulting from step a), in the emulsification chamber

Methodology Applied
Scientific EffectShear stress: Shear Stress

Implementation Method 2

the function of such compositions is to avoid the coalescence of the ASA particles by positive ionization of the surface of the particles

Methodology Applied
Scientific EffectIonic mechanism: Ion Repulsion/Attraction

Implementation Method 3

dilute the emulsion resulting from step d) in the immediate vicinity of the outlet of the emulsification unit... to obtain a minimum speed of the fluid in a pipe downstream of the dilution device, greater than 0.2 m/s

Methodology Applied
Scientific EffectFluid flow:

Data Source

PatentEP2929929B1Method for producing an alkenyl succinic anhydride emulsion
Publication Date: 2017.07.12 ROQUETTE FRERES SA
  • EP2929929B1 patent drawingFigure 1
  • EP2929929B1 patent drawingFigure 2
  • EP2929929B1 patent drawingFigure 3

AI summary

A process for the continuous production of an ASA emulsion in an aqueous solution of cationic starch, implemented using an emulsification unit (1) comprising an emulsification chamber (2) receiving a rotor (3)/stator (4) assembly, the process comprising the steps of: - a) preparing an aqueous solution of cationic starch having a dry matter content of between 7% and 12% by weight, - b) separately conveying the ASA and the aqueous solution of starch from step a) and feeding the emulsification chamber with ASA and the aqueous solution of starch from step a), respectively, by means of two separate fluid inlets (E1, E2), so as not to mix them before their introduction into the emulsification chamber (2), - c) mixing the ASA and the aqueous solution of cationic starch from step a) in the chamber emulsification (2),in order to obtain a dry weight ratio of cationic starch/ASA of less than 1, preferably between 0.2 and 0.6 and very preferably between 0.25 and 0.5, - d) produce in a single pass in the emulsification unit (1) an emulsion from the mixture of step c), without a recirculation loop, - e) dilute the emulsion from step d) by a factor between 4 and 21.