Semi-Continuous Toner Production Reactor Design

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Solution Overview

Problem

Continuous processes for producing toner particles face challenges such as blockages in conduits due to solid products and altered reaction kinetics, making them unsuitable for commercial use, while batch processes are inefficient and time-consuming.

Innovation Solution

A semi-continuous process combining batch and continuous reaction schemes, where aggregated particles from a batch reactor are treated in a continuous reactor with controlled temperature and flow conditions to achieve coalescence and finishing processes, reducing ramping and coalescence time to about 5 minutes or less.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a continuous process is used for producing toner, then productivity and reaction efficiency are improved, but conduit blockages occur due to solid products

Engineering Contradiction:
Improveproduction capacityVSAvoidconduit blockage risk
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The continuous process is segmented into multiple functional zones within the reactor: a first zone for aggregation reactions and a second zone for coalescence reactions. This segmentation allows solid toner particles to form and grow in the first zone, then continue maturing in the second zone without blocking conduits, as the reaction chambers are internally configured to handle solid-liquid slurries continuously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A slurry medium serves as an intermediary carrier, suspending solid toner particles and reaction byproducts throughout the continuous process. The slurry allows solid products to be transported through the reactor system without clogging conduits, maintaining continuous flow while accommodating solid particle formation and growth.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of time

If a continuous process is used for producing toner, then reaction time is reduced, but reaction kinetics are altered affecting product quality

Engineering Contradiction:
Improvereaction timeVSAvoidtoner particle quality
Core Design Contradiction:
Loss of timeVSManufacturing precision

Solution Approach 1:

The reactor employs dynamic temperature control with separate temperature zones: the first zone operates at a temperature conducive to aggregation, while the second zone operates at a different temperature optimized for coalescence. This dynamic thermal profile allows rapid processing while maintaining appropriate reaction kinetics for each stage, preserving toner particle quality despite reduced overall reaction time.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Different regions of the reactor are assigned different local conditions: the first zone provides conditions optimized for aggregation (specific temperature, mixing intensity), while the second zone provides conditions optimized for coalescence (different temperature, flow characteristics). This local optimization ensures each reaction stage proceeds with appropriate kinetics, maintaining product quality throughout the accelerated continuous process.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If batch process is used for producing toner, then reaction control is simplified, but productivity and efficiency are reduced

Engineering Contradiction:
Improvereaction control simplicityVSAvoidproduction efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The process transitions from discrete batch operations to continuous operation, where reactants continuously flow through the reactor and products continuously exit. This eliminates idle time between batches, maintains constant reaction conditions, and maximizes equipment utilization, dramatically improving productivity while the modular reactor design keeps control straightforward.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The reactor is pre-configured with integrated mixing elements, heating/cooling zones, and flow control mechanisms that automatically maintain optimal reaction conditions throughout continuous operation. This preliminary design of the reaction environment eliminates the need for manual intervention between batches, maintaining ease of operation while achieving continuous high-speed production.

Inventive Principle:
Principle #10Preliminary 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

This hybrid process increases production capacity, reduces impurities and secondary reactions, and achieves comparable toner properties to batch-produced toners with improved efficiency and yield.

Implementation Method 1

The heating and cooling elements can be positioned along the communication devices and along the flow path of the continuous reactor to provide a controlled or particular temperature profile for the communicated reactants within the communication device and the reactor

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

The heating and cooling elements can be positioned along the communication devices and along the flow path of the continuous reactor to provide a controlled or particular temperature profile

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 3

A pump or urging device causes movement the slurry from the batch reactor to the continuous reactor

Methodology Applied
Scientific EffectPumping: Pump

Implementation Method 4

The continuous reactor can comprise one or more temperature regulating devices, such as, a heating or cooling element, which can comprise a liquid, such as, an oil, that bathes the directed parallel flow path to provide the appropriate temperature or temperature profile along the flow path

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 5

The reaction apparatus can be operated under pressure to reduce reagent and fluid boiling points and to ensure unimpeded or continuous movement and uniform flow of the reaction mixture through the reactor

Methodology Applied
Scientific EffectPressure: Pressure Increase

Data Source

PatentUS8956797B2Batch/continuous production of toner
Publication Date: 2015.02.17 XEROX CORP

AI summary

A process for forming toner using an emulsion/aggregation scheme wherein particle aggregation occurs in a batch reactor and coalescence occurs in a continuous reactor. In embodiments, a continuous reactor comprises four sections joined in series.