Liquid discharge apparatus
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Solution Overview
Problem
Existing direct-to-garment (DTG) printers face challenges in consecutively performing pretreatment, foundation formation, and color printing without deteriorating image quality, especially when dealing with fabrics that require high adhesiveness and fixability of ink.
Innovation Solution
A serial type liquid discharge apparatus with multiple heads and carriages, where a first head discharges a pretreatment liquid, a second head discharges white ink, and a third head discharges color ink, all in a specific nozzle resolution relationship and with controlled line feed and head arrangement, allowing for consecutive application of pretreatment, foundation formation, and color printing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the viscosity of the pretreatment liquid is increased or a large amount of the pretreatment liquid is applied to the fabric, then the adhesiveness of the image is enhanced, but the discharging property of the inkjet head is affected or the apparatus size increases
Solution Approach 1:
The patent applies parameter changes by adjusting the viscosity of the pretreatment liquid to an optimal range (10-100 cP) and controlling the application amount (0.1-10 mL/m²) to maintain both good discharging properties and image adhesiveness. This resolves the contradiction by finding the optimal parameter values that satisfy both requirements simultaneously.
2Device complexity
If a series of operations from pretreatment to printing is performed by the same apparatus, then apparatus cost and operation cost are reduced, but ink may be discharged to positions outside the application area or foundation area causing image deterioration
Solution Approach 1:
The patent implements feedback control by using a conveyance amount detection unit to monitor the actual conveyance amount of the fabric and a discharge amount detection unit to monitor the pretreatment liquid discharge amount. The controller adjusts the discharge amounts based on detected variations, ensuring precise application within the intended areas even when multiple operations are integrated in one apparatus.
3Manufacturing precision
If the resolution of the pretreatment liquid is higher than the resolution of color ink, then high quality images are formed, but control becomes more difficult in serial type DTG printers performing multi-pass printing
Solution Approach 1:
The patent applies dynamics by making the conveyance amount adjustable and controllable during the printing process. The conveyance amount detection unit detects variations in fabric conveyance, and the controller dynamically adjusts the discharge amounts of pretreatment liquid and ink accordingly. This dynamic control system handles the complexity of multi-resolution printing in serial type DTG printers while maintaining high image quality.
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
This configuration enables the DTG printer to consecutively apply pretreatment, form a foundation, and print with color ink as a single integrated apparatus, enhancing image robustness and quality while reducing apparatus size and operation costs.
Implementation Method 1
a first head to discharge a pretreatment liquid from first nozzles onto a medium
Implementation Method 2
a second head to discharge a white ink from second nozzles onto the medium, onto which the pretreatment liquid has been discharged
Implementation Method 3
a third head to discharge a color ink other than white from third nozzles onto the medium, onto which the pretreatment liquid and the white ink have been discharged
Implementation Method 4
The conveyor intermittently conveys the medium by an amount of line feed W of the medium in a sub-scanning direction orthogonal to the main scanning direction
Data Source
Figure 1A~1B
Figure 2A~2F
Figure 3A~3C
AI summary
A liquid discharge apparatus includes multiple heads (20) including a first head (11) to discharge a pretreatment liquid in resolution N1, a second head (12) to discharge a white ink in resolution N2, and a third head (13) to discharge a color ink in resolution N3, multiple carriages (20), and a conveyor (61). Expressions of N1 ≥ N2 ≥ N3, N1 / N3 = m, N2 / N3 = n, and m ≥ n are satisfied. The conveyor (61) intermittently conveys the medium by an amount of line feed W of the medium in response to one movement of the third head (13). The first head (11) is arranged at a first distance L1 from the second head (12). The second head (12) is arranged at a second distance L2 from the third head (13). Expressions of L1 = W × p, and L2 = W × q are satisfied.