Heating Roller Temperature Gradient for Startup Cockling
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Solution Overview
Problem
In printing systems, especially rotary presses and inkjet methods, issues such as image blur, color tone changes, and cockling (wave-shaped deformation) occur when using non-manufacturer-specified paper, leading to poor initial image quality and robustness concerns, and existing drying devices are complex and ineffective in preventing cockling during startup.
Innovation Solution
A recording medium heating device with multiple heating rollers and a controller that sets temperature gradients along the conveying path, where the roller closest to the exit has a lower temperature than those further away, to prevent cockling during startup and ensure efficient drying without causing deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple heating rollers are used to dry the recording medium, then drying efficiency is improved, but cockling (wave-shaped deformation) occurs during startup
Solution Approach 1:
The patent applies local quality by setting different temperature levels for different heating rollers based on their position in the conveying path. Specifically, heating rollers closer to the exit side are set to lower temperatures while those farther from the exit side are set to higher temperatures during startup. This localized temperature differentiation prevents uniform overheating that causes cockling, while still achieving effective drying through the gradient distribution of thermal energy across multiple rollers.
2Productivity
If heating temperature is increased to improve drying speed, then productivity increases, but cockling deformation worsens
Solution Approach 1:
The patent implements parameter changes by dynamically adjusting the temperature parameters of individual heating rollers based on their positional parameters in the conveying path. During startup, the system sets temperature parameters such that rollers nearer the exit operate at lower temperatures while rollers farther away operate at higher temperatures. This parameter differentiation allows the system to maintain high overall drying speed while preventing the uniform high-temperature exposure that leads to cockling deformation.
3Stability of the object's composition
If uniform temperature is applied across all heating rollers, then drying uniformity is improved, but cockling occurs due to excessive heat load
Solution Approach 1:
The patent resolves this contradiction by applying local quality principles through position-based temperature differentiation. Instead of uniform temperature application, each heating roller is assigned a specific temperature level according to its location in the conveying path, with exit-side rollers at lower temperatures and entrance-side rollers at higher temperatures during startup. This creates a controlled temperature gradient that maintains drying effectiveness while distributing heat load unevenly to prevent cockling.
4Productivity
If heating rollers are operated at high temperature during startup, then drying performance is improved, but service life of heating rollers decreases
Solution Approach 1:
The patent applies parameter changes by implementing time-based and position-based temperature control strategies. During the startup phase, heating rollers are operated at reduced temperature parameters compared to normal operation, with specific regard to their positional parameters. Exit-side rollers are set to lower temperatures while entrance-side rollers operate at moderately elevated temperatures. This parameter modulation maintains adequate drying performance while reducing thermal stress on the heating rollers, thereby extending their service life.
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 effectively reduces cockling and improves image quality by maintaining temperature control, minimizing heat load on the recording medium, and preventing deformation, allowing for uniform drying and extended service life of heating rollers.
Implementation Method 1
In printing systems, such as rotary presses, in order to evaporate the solvent of ink printed on a sheet, there is a technique in which a sheet is dried by multiple heating rollers provided on the conveying path of the sheet
Implementation Method 2
multiple heating rollers, including respective heaters, disposed on a conveying path of the recording medium
Data Source
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AI summary
A recording medium heating device (120, 350) that can heat and dry a continuous recording medium (10), includes multiple heating rollers(40a, 40b, 50a, 50b, 60a, 60b), including respective heaters(41a, 41b, 51a, 51b, 61 a, 61b), disposed on a conveying path of the recording medium; and a controller (80, 80b) to control the heaters of the heating rollers. In a starting period during which the recording medium heating device is started, the controller sets temperatures of the heaters to starting temperatures where a temperature of a heating roller positioned closest to an exit side of the conveying path is lower than a temperature of a heating roller positioned away from the exit side of the conveying path.