Fixing Roller Thermal Conductivity and Nip Width Optimization
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Solution Overview
Problem
Existing fixing rollers for high-speed printers are unsuitable due to early wear of the fluororesin layer on silicone rubber and inadequate nip width, leading to issues with durability, heat resistance, and image quality.
Innovation Solution
A fixing apparatus with a heat roller having a thermal-conductivity-enhanced rubber layer and a fluororesin layer, where the rubber layer thickness ranges from 200 μm to 600 μm and the fluororesin layer thickness ranges from 80 μm to 300 μm, combined with a pressure roller of 70 mm or more diameter, to enhance heat transfer and maintain image quality at high speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fluororesin layer is formed on a silicone rubber layer to improve durability and heat resistance, then durability and heat resistance are improved, but the fluororesin layer is worn early in high-speed printers
Solution Approach 1:
The invention changes the thickness parameter of the rubber layer to 200-600 μm (thicker than conventional rollers) and optimizes the rubber hardness to 40-80 degrees JIS-A. These parameter changes allow the rubber layer to provide sufficient cushioning and heat conduction while reducing mechanical stress on the fluororesin layer, thereby preventing early wear in high-speed printing conditions.
Solution Approach 2:
The invention uses a composite structure with a thermal-conductivity-enhanced rubber layer as the base and a fluororesin layer as the outer layer. The rubber layer provides elasticity, cushioning, and heat conduction, while the fluororesin layer provides durability and non-stick properties. This composite structure allows each layer to perform its optimal function without compromising the other.
2Area of stationary object
If the diameter of fixing rollers is increased to provide sufficient nip width for high-speed printers, then nip width is improved, but the rollers become larger and more complex
Solution Approach 1:
The invention increases the diameter parameter of the fixing rollers to provide sufficient nip width for high-speed printing. The larger diameter allows the rollers to maintain adequate contact width (nip width) even at high rotational speeds, ensuring proper heat transfer and pressure distribution across the recording medium.
3Manufacturing precision
If a rubber layer with sufficient thickness is used to provide cushioning and heat conduction, then image quality is improved, but heat transfer efficiency decreases
Solution Approach 1:
The invention optimizes the rubber layer thickness to 200-600 μm, which is thicker than conventional rollers to provide sufficient cushioning for high-quality image fixation. Simultaneously, the rubber hardness is controlled at 40-80 degrees JIS-A to balance softness (for cushioning) and thermal conductivity (for heat transfer efficiency).
Solution Approach 2:
The invention creates a thermal-conductivity-enhanced rubber layer that combines rubber material with heat conduction enhancement. This composite material provides both the cushioning properties needed for image quality and improved thermal conductivity to maintain heat transfer efficiency despite the increased thickness.
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 solution provides secure fixing strength and high image quality even at high speeds, enabling continuous printing of over five million pages without issues related to fixing strength or durability.
Implementation Method 1
a rubber layer that is formed on the cylindrical core and includes a thermal-conductivity-enhanced rubber
Implementation Method 2
a heat source that generates heat to be supplied on a toner image formed on a recording medium
Implementation Method 3
a pressure roller that presses the recording medium against the heat roller
Data Source
AI summary
According to an aspect of the present invention, there is provided a fixing apparatus including: a heat roller that includes: a heat source that generates heat to be supplied on a toner image formed on a recording medium; a cylindrical core; a rubber layer that is formed on the cylindrical core and includes a thermal-conductivity-enhanced rubber, the rubber layer having a thickness of Tg that satisfies 200 μm≦Tg≦600 μm and having a rubber hardness defined by JIS-A hardness of Hg that satisfies 40 degrees≦Hg≦80 degrees; and a fluororesin layer that is formed on the rubber layer, the fluororesin layer having a thickness of Tj that satisfies 80 μm≦Tj≦300 μm and 2 Tj≦Tg≦10 Tj; and a pressure roller that presses the recording medium against the heat roller.