PFA Surface Layer Control for Wear-Resistant Fixing Members
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrophotographic fixing members face challenges in achieving a balance between wear resistance, image glossiness, and flexibility to follow paper sheet unevenness due to issues with surface layer crystallinity and molecular rigidity, leading to reduced image quality.
Innovation Solution
The electrophotographic member comprises a base layer, an elastic layer, and a surface layer with a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) having controlled endothermic properties and spherulite size, ensuring an endothermic peak temperature of 304°C or less, an endothermic quantity of 21 J/g or more, and an area average spherulite diameter of 40 μm or less.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If PFA is gradually cooled to increase crystallinity and wear resistance, then wear resistance is improved, but surface smoothness is reduced due to large spherulite formation
Solution Approach 1:
The patent applies parameter changes by controlling the cooling rate during solidification to optimize the balance between crystallinity and spherulite size. By adjusting the cooling rate parameter, the patent achieves high wear resistance through increased crystallinity while preventing excessive spherulite growth that would compromise surface smoothness.
Solution Approach 2:
The patent employs preliminary action by introducing a nucleating agent before the solidification process to pre-establish numerous small spherulite nuclei. This preliminary nucleation prevents large spherulite formation during cooling, thereby maintaining surface smoothness while still achieving sufficient crystallinity for wear resistance.
2Strength
If PFA with high melting point is used to increase rigidity and wear resistance, then wear resistance is improved, but flexibility is reduced
Solution Approach 1:
The patent applies parameter changes by carefully selecting and controlling the melting point range of PFA (270-304°C) to achieve the optimal balance between rigidity for wear resistance and flexibility for following paper sheet unevenness. The patent also controls the endothermic quantity parameter to ensure appropriate molecular chain flexibility.
Solution Approach 2:
The patent uses composite materials by combining PFA with specific additives or blending it with other polymers to achieve the desired balance between wear resistance and flexibility. The composite structure allows the material to exhibit both the rigidity needed for wear resistance and the flexibility needed to conform to paper sheet surfaces.
3Manufacturing precision
If spherulite size is reduced to improve surface smoothness, then surface smoothness is improved, but wear resistance may be compromised
Solution Approach 1:
The patent employs preliminary action by introducing a nucleating agent before the solidification process to pre-establish numerous small spherulite nuclei. This preliminary nucleation ensures that many small spherulites form during cooling, achieving high surface smoothness while the collective crystalline structure provides sufficient wear resistance.
Solution Approach 2:
The patent applies parameter changes by optimizing the cooling rate and nucleating agent concentration to achieve the optimal distribution of spherulite sizes. By adjusting these parameters, the patent maximizes surface smoothness through small spherulites while maintaining adequate crystallinity for wear resistance.
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 configuration enhances wear resistance, maintains image glossiness, and improves flexibility to handle paper sheet unevenness, stabilizing high-quality electrophotographic image formation.
Implementation Method 1
the surface layer is heated to a temperature equal to or higher than the melting point of PFA, followed by gradual cooling
Implementation Method 2
an endothermic peak temperature in a second temperature raising process is 304°C or less
Implementation Method 3
increasing the degree of crystallinity of the PFA
Implementation Method 4
a large spherulite may be formed on the surface of the surface layer
Data Source
AI summary
An electrophotographic member comprising: at least a base layer; an elastic layer; and a surface layer in this order, wherein the surface layer comprises a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, at an endothermic curve upon performing two measurements at a ramp up rate and a ramp down rate both set at 20° C./min using a differential scanning calorimeter (DSC) with a sample sampled from the surface layer as a measurement sample, an endothermic peak temperature in a second temperature raising process is 304° C. or less, an endothermic quantity in a first temperature raising process is 21J/g or more, and D3 is 40 μm or less, where D3 represents an area average diameter of a spherulite at an outer surface of the surface layer.