Toner Surface Modification Apparatus for Sphericity and Fine Powder Removal
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Solution Overview
Problem
Existing methods for producing toner particles, such as mechanical pulverization and hot air treatment, fail to achieve high sphericity and stability, leading to issues like image fog and reduced classification efficiency.
Innovation Solution
A batch-wise surface modifying apparatus that simultaneously classifies and surface-modifies toner particles using a dispersing rotor and liner, with a specific gap and disk configuration to prevent over-pulverization and maintain heat control, resulting in spherical toner particles with improved sphericity and surface properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If mechanical pulverization is used to make toner particles spherical, then production cost is reduced, but sphericity cannot be sufficiently achieved
Solution Approach 1:
The invention divides the particle modification process into distinct stages: coarse pulverization followed by fine pulverization with classification. This segmentation allows each stage to be optimized independently - coarse pulverization reduces size while fine pulverization with classification achieves sphericity, resolving the contradiction between cost and shape quality
Solution Approach 2:
The invention employs dynamic classification during the pulverization process, where particles are continuously classified by size and fed back for further processing. This dynamic approach enables the system to achieve high sphericity by repeatedly processing particles until they meet the spherical shape requirement, while maintaining cost-effectiveness through efficient material utilization
2Shape
If hot air action is used to make toner particles spherical, then sphericity is improved, but wax melts and surface properties become difficult to control
Solution Approach 1:
The invention replaces thermal action (hot air) with mechanical action (pulverization and classification) to achieve sphericity. This substitution eliminates the risk of wax melting and surface property degradation, while still achieving the desired spherical shape through controlled mechanical forces and classification
Solution Approach 2:
The invention changes the operating parameters from thermal parameters (temperature) to mechanical parameters (pulverization intensity, classification cutoff sizes). This parameter transformation allows achieving sphericity through mechanical means without triggering thermal degradation of surface properties and wax components
3Shape
If high degree of making spherical is maintained using existing surface modifying apparatus, then sphericity is improved, but fine-powder removal efficiency lowers and image fog occurs
Solution Approach 1:
The invention segments the particle processing into coarse pulverization and fine pulverization with classification stages. The classification stage specifically targets and removes fine powder while the pulverization stage maintains sphericity, allowing both high sphericity and high fine-powder removal efficiency to be achieved simultaneously without causing image fog
Solution Approach 2:
The invention implements a feedback mechanism where particles are classified by size, and fine powder is separated and removed while larger spherical particles are retained. This feedback loop ensures that only particles meeting the size and shape requirements proceed to the final product, maintaining both sphericity and fine-powder removal efficiency while preventing image fog
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 produces toner particles with high sphericity, reduced fine powder, and enhanced developing, transfer, and cleaning performance, while preventing image fog and improving yield.
Implementation Method 1
a surface modifying means having a dispersing rotor which rotates in the same direction as the rotational direction of the classifying rotor and a liner which is stationarily disposed, in order that particles contained in the finely pulverized product from which the fine powder and ultrafine powder have been removed are subjected to surface modification treatment using a mechanical impact force
Implementation Method 2
a classifying means having a classifying rotor which rotates in a stated direction in order that fine powder and ultrafine powder having particle diameter not larger than stated particle diameter are continuously removed out of the apparatus from the finely pulverized product having been introduced into the main-body casing
Data Source
AI summary
In a toner production process having at least a kneading step, a pulverization step and the step of simultaneously carrying out a surface modification step and a classification step to obtain toner particles, the surface modification and the classification are simultaneously carried out using a batch-wise surface modifying apparatus having at least a cylindrical main-body casing, a classifying rotor, a surface modifying means having a dispersing rotor and a liner. The positional relationship between the dispersing rotor and the liner is set in an appropriate specific state so that toner particles having a sharp particle size distribution with less fine powder and having a high sphericity can be obtained in a good efficiency.