Developing Roller Surface Layer for Wear and Peeling Resistance
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Solution Overview
Problem
Developing rolls in electrophotographic image forming apparatuses face durability issues due to the forces exerted during contact with the photoconductor drum and regulation blade, leading to wear and peeling of the surface layer.
Innovation Solution
A developing roll design comprising a metal core, a rubber elastic layer, and a rubber surface layer with specific compressive strength and toughness indices (X ≥ 65.6 N/mm³ and Y ≥ 229 µm) to enhance durability, minimizing abrasion and peeling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the developing roll is subjected to force from the doctor blade and contact with the photoconductor drum, then the developing function is achieved, but the durability of the developing roll deteriorates due to wear and peeling
Solution Approach 1:
The invention changes the physical-chemical parameters of the surface layer by controlling the polymerization conversion rate (70-90%) and adjusting the composition ratio of polymerizable monomers and oligomers. This optimization achieves the target compressive strength (X ≥ 65.6 N/mm³) while maintaining flexibility, thereby improving wear resistance and durability under operational forces from the doctor blade and photoconductor drum contact
Solution Approach 2:
The surface layer is constructed as a composite material system combining polymerizable monomers and oligomers with specific functional groups. This composite structure provides both the required mechanical strength (compressive strength X ≥ 65.6 N/mm³) and elasticity, creating a material that resists wear and peeling while maintaining the necessary flexibility for developing roll operation
2Reliability
If the surface layer is made harder to resist wear, then durability improves, but the roll becomes less flexible and more prone to cracking under repeated deformation
Solution Approach 1:
The invention optimizes the polymerization conversion rate parameter (70-90%) to achieve a balance between hardness and flexibility. This controlled parameter change ensures the surface layer attains sufficient compressive strength (X ≥ 65.6 N/mm³) for wear resistance while maintaining the elastic properties needed to withstand repeated deformation without cracking
Solution Approach 2:
The surface layer is designed with specific local properties by selecting monomers and oligomers with particular functional groups that provide both wear resistance and flexibility. This localized optimization of material composition ensures that the surface layer has the precise combination of hardness and elastic recovery needed to resist wear while preventing crack formation under operational stress
Data Source
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AI summary
A developing roll has a metal core member, an elastic layer disposed around the core member, and a surface layer disposed around the elastic layer. In the developing roll, a value X is equal to or greater than 65.6 N/mm3 and a value Y is equal to or greater than 229 µm. The value X is calculated from P1/(D2 × A) - P2/(D2 × A). P1 is the load required to displace the developing roll by a depth of 100 µm in a radial direction when a truncated cone-shaped metal probe having a distal end of which a diameter is 40 µm is pressed against the developing roll. D1 is the displacement of the developing roll caused by the probe under the load P1. A is the distal end area of the probe. P2 is the load required to displace a material roll by a depth of 100 µm in a radial direction when the probe is pressed against the material roll that includes the core member and the elastic layer and does not include the surface layer. D2 is the displacement of the material roll caused by the probe under the load P2. The value Y is the displacement of the developing roll caused by the probe when the probe, which is pressed against the developing roll and is displaced in a radial direction of the developing roll, pierces the surface layer.