Cleaning Blade Surface Layer Hardness Gradient
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Solution Overview
Problem
Conventional cleaning blades fail to effectively remove polymerization toner from image bearers due to slippage through gaps, leading to defective cleaning, and suffer from turn-up, abnormal noise, and wear issues, especially at higher speeds and with micro waviness, resulting in torque increases and color shifts in tandem systems.
Innovation Solution
A cleaning blade with an elastic member and a surface layer containing a siloxane-based compound, featuring a hardness gradient from the surface to the base material, and an average film thickness of 10 µm to 500 µm, which prevents tip ridge turn-up and excessive wear, maintaining cleaning performance over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the contact pressure between the cleaning blade and image bearer is increased to suppress slippage and enhance cleaning ability, then the cleaning performance is improved, but turn-up is caused leading to local wear and eventual missing of the tip ridge
Solution Approach 1:
The cleaning blade is designed with a surface layer having different hardness properties than the base material. The surface layer has lower hardness (2.5-32.5 N/mm²) to prevent turn-up and wear, while the base material maintains the necessary elasticity and contact pressure. This local differentiation of material properties resolves the contradiction between achieving sufficient contact pressure for cleaning and preventing wear that would reduce service life.
2Duration of action of stationary object
If the film thickness of the surface layer is increased to prevent wear and turn-up, then the durability is improved, but the manufacturing precision and edge accuracy are degraded
Solution Approach 1:
The patent specifies a controlled film thickness range of 10-500 µm for the surface layer, which is sufficient to prevent wear and turn-up while maintaining manufacturing feasibility. By optimizing this parameter within the given range, the patent achieves both durability and acceptable manufacturing precision, avoiding the extremes that would cause either excessive wear or manufacturing difficulties.
3Productivity
If the image forming speed is increased to meet demand for speed-up, then the productivity is improved, but the image bearer is finely vibrated due to axial deviation and the cleaning blade fails to cope with the vibration and micro waviness
Solution Approach 1:
The cleaning blade's contact pressure and surface layer properties are optimized to maintain effective cleaning contact even under vibration conditions at high speeds. The elastic member and surface layer configuration allows the blade to adapt to micro waviness and axial deviation while maintaining sufficient contact for effective cleaning, thus preserving cleaning performance despite the vibrational effects of high-speed operation.
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 cleaning blade effectively suppresses abnormal noise and wear, maintains long-term cleaning ability, and prevents color shifts by ensuring proper contact and reduced friction, even at high speeds and with micro waviness, enhancing followability and durability.
Implementation Method 1
The surface layer contains a siloxane-based compound... effectively suppresses abnormal noise and wear, maintains long-term cleaning ability... reduced friction
Implementation Method 2
an elastic member to contact a surface of a cleaning target member... elastic member made of a polyurethane elastomer
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
A cleaning blade includes an elastic member to contact a surface of a cleaning target member. The elastic member includes a base material and a surface layer on at least a part of a lower surface of the base material including a contact part. Martens hardness of the surface layer has a gradient of decrease from a surface of the surface layer toward the lower surface of the base material in a film thickness direction. The Martens hardness is 2.5 to 32.5 N/mm2 in a range from a vicinity of the surface (with a load of 1 μN) to a deepest part in the film thickness direction (with a load of 1000 μN). An average film thickness of the surface layer is 10 μm or more to 500 μm or less. A content of a siloxane-based compound in the surface layer is 4 to 15% by mass.