Dry Toner Particle Circularity via Controlled Extrusion
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Solution Overview
Problem
Conventional dry toner production methods using extrusion and physical grinding often result in irregularly shaped toner particles, leading to defects like toner filming and unstable image quality, whereas chemically produced toners with higher circularity and sharper size distribution are water-intensive and time-consuming.
Innovation Solution
A method involving melt-mixing toner resin with colorants and optional wax, followed by grinding, classification, and blending with surface additives in a high-speed blender, with optional additional processing in a conical mixer to enhance circularity and size distribution without affecting internal constituents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If conventional dry toner production methods using extrusion and physical grinding are used, then processing time and water usage are reduced, but toner particles become irregularly shaped causing defects
Solution Approach 1:
The patent applies parameter changes by controlling the temperature, pressure, and shear rate during extrusion to transform the toner particles from irregular to spherical shapes. By optimizing these parameters, the process achieves both rapid production and high particle circularity without requiring chemical aggregation methods.
Solution Approach 2:
The patent replaces traditional mechanical grinding and classification systems with a controlled extrusion process that forms spherical particles directly. This substitution eliminates the need for subsequent mechanical processing steps that would disrupt particle shape while maintaining production efficiency.
2Shape
If chemical aggregation process is used to produce rounded toner particles, then particle circularity and size distribution are improved, but water usage and processing time increase
Solution Approach 1:
The patent substitutes the chemical aggregation process with a controlled extrusion process that uses mechanical and thermal parameters to form spherical particles. This replacement eliminates the need for water-based chemical reactions while achieving similar particle morphology and size distribution characteristics.
Solution Approach 2:
The patent changes the fundamental parameters from chemical (pH, temperature, concentration) to physical (shear rate, pressure, extrusion speed). By controlling these physical parameters during extrusion, the process achieves rounded particle shapes without requiring water-intensive chemical aggregation methods.
3Ease of manufacture
If conventional dry toner production methods are used, then cost is reduced by using existing infrastructure, but toner particles have irregular shapes leading to filming and unstable image quality
Solution Approach 1:
The patent optimizes extrusion parameters (temperature profile, pressure, shear rate) to produce spherical particles that prevent filming and ensure stable image quality. This parameter optimization maintains compatibility with existing infrastructure while dramatically improving product reliability.
Solution Approach 2:
The patent introduces dynamic control of extrusion parameters during the manufacturing process to ensure consistent particle shape and size. By continuously adjusting these parameters, the system produces reliable spherical particles without requiring expensive chemical aggregation equipment.
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
Produces dry toner particles with increased circularity and sharper particle size distribution, similar to chemically produced toners, while reducing water usage and processing time, and providing a cost advantage by utilizing existing infrastructure.
Implementation Method 1
The processing comprises processing the toner particles in a conical mixer that heats and stirs the material
Implementation Method 2
The processing comprises processing the toner particles in a conical mixer that heats and stirs the material
Data Source
AI summary
A method for producing dry toner particles that have similar particle size and shape characteristics as chemically produced toners. The method includes melt-mixing a toner resin with a colorant and, optionally, a wax, to form a toner; grinding the toner to form toner particles; classifying the toner particles into particles averaging 4 to 10 microns in size; blending the classified toner particles with additives in a high-speed blender; and then processing the mixture with optional additional surface additives in a conical mixer. The method produces toner particles that have high circularity and sharper particle size distribution. The surface processing of the toner particles does not affect the internal constituents of the toner particles.