Inkjet Image Formation with Speed-Adaptive Pretreatment
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Solution Overview
Problem
Ink jet printing apparatuses using a two-liquid coagulation system face limitations in increasing printing speed and stability due to roller coating methods, leading to issues like film strength decrease, blocking, curling, and cockling, especially at higher transportation speeds.
Innovation Solution
An image forming apparatus that switches between a two-liquid coagulation system and a one-liquid coagulation system based on transportation speed, along with adjustable drying intensity, ink droplet volume, and printing resolution to balance high image quality and productivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If roller coating method is used for pretreatment liquid coating, then coating stability is improved, but transportation speed cannot be increased further
Solution Approach 1:
The patent replaces the mechanical roller coating method with a spray coating method. The spray coating device includes a spray head that sprays pretreatment liquid onto the recording medium in a controlled manner, allowing for higher transportation speeds while maintaining coating stability. This substitution of mechanical coating with spray-based coating enables the system to operate at faster speeds without compromising coating quality.
Solution Approach 2:
The patent changes the coating parameters by introducing a spray coating mechanism that can adjust spray pressure, spray angle, and pretreatment liquid flow rate independently. This allows optimization of coating parameters at higher transportation speeds, maintaining stable coating while enabling increased speed operation.
2Productivity
If transportation speed is increased to improve productivity, then printing speed is improved, but film strength decreases and blocking occurs
Solution Approach 1:
The patent applies pretreatment liquid to the recording medium before ink jetting, creating a preliminary coating layer that enhances film strength. This preliminary action ensures that when ink is jetted at high speeds, the resulting film maintains sufficient strength and resistance to blocking, even though the overall process time is reduced.
Solution Approach 2:
The pretreatment liquid acts as an intermediary substance between the recording medium and the ink. It forms a bridge layer that improves ink adhesion and film strength, allowing high-speed printing without compromising the mechanical properties of the printed film.
3Productivity
If transportation speed is increased, then productivity is improved, but drying time is shortened leading to curling and cockling
Solution Approach 1:
The patent applies pretreatment liquid to the recording medium in advance, which facilitates faster drying of the ink after jetting. This preliminary coating preparation allows the ink to dry more efficiently at higher transportation speeds, reducing curling and cockling issues that would otherwise occur due to insufficient drying time.
Solution Approach 2:
The spray coating method allows for precise control of pretreatment liquid application parameters, creating an optimal coating thickness and composition that enhances drying speed. This enables the system to maintain adequate drying time even at increased transportation speeds, preventing curling and cockling.
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
Enables high-quality printing and high productivity by adapting to different transportation speeds, reducing drying time requirements, and maintaining film quality.
Implementation Method 1
a printing head that jets ink to the recording medium coated with the pretreatment liquid
Implementation Method 2
ink is jetted after transported paper is coated with a pretreatment liquid to coagulate a coloring material
Data Source
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AI summary
Provided are an image forming apparatus 1 and a method of manufacturing a printed material, capable of meeting user requirements for both high image quality printing and high productivity printing. The image forming apparatus 1 includes: a transport mechanism 11 that transports a recording medium P; a coating device 24 that coats the recording medium P with a pretreatment liquid; an inkjet head 46; and a processor 300, in which the processor 300 is configured to, in a case where the recording medium P is transported at a first transportation speed and an ink is jetted from the ink jet head 46 to form an image on the recording medium P, perform control to cause the coating device 24 to perform coating with the pretreatment liquid, and in a case where the recording medium P is transported at a second transportation speed faster than the first transportation speed to form the image on the recording medium P, perform control to cause the coating device 24 not to perform coating with the pretreatment liquid.