Method for preparing ink film constructions
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Solution Overview
Problem
Current inkjet printing technologies face challenges in achieving high-quality ink film constructions on fibrous substrates, particularly due to issues like ink penetration, surface wetting, and image quality, which are exacerbated by the physical properties of the substrates, and existing solutions like coated substrates are costly and impractical for all printing applications.
Innovation Solution
The development of ink film constructions featuring continuous ink dots with specific viscosity ranges and nitrogen concentration gradients, adhered to uncoated or coated fibrous substrates, where the ink dots have controlled thickness and convex shapes, ensuring minimal penetration and improved surface adhesion, using an intermediate transfer member with modified surface chemistry to manage ink spreading and drying.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If inkjet printing is performed directly onto porous fibrous substrate, then printing process is simple, but image quality deteriorates due to ink penetration and substrate wicking
Solution Approach 1:
The patent introduces an intermediate transfer member (ITM) as a mediator between the inkjet print head and the fibrous substrate. The ITM receives the inkjet image, allows it to dry, and then transfers it to the substrate. This intermediary approach prevents direct ink-substrate interaction that causes quality issues, while maintaining process simplicity.
Solution Approach 2:
The inkjet image is formed and dried on the intermediate transfer member before being transferred to the final substrate. This preliminary formation and drying step ensures the ink is properly set and prevents unwanted penetration or wicking when the image contacts the fibrous substrate.
2Manufacturing precision
If specially coated substrates are used to control ink absorption, then image quality improves, but cost increases
Solution Approach 1:
The intermediate transfer member serves as a mediator that enables high-quality imaging on ordinary, uncoated substrates. By forming and drying the ink image on the ITM first, the system achieves controlled ink deposition without requiring expensive specially coated substrates.
Solution Approach 2:
The system uses ordinary, inexpensive fibrous substrates instead of expensive specially coated ones. The substrate's role is limited to receiving the pre-formed image, and its ordinary composition is sufficient when combined with the intermediate transfer approach.
3Manufacturing precision
If coated substrates are used to prevent ink penetration, then image quality improves, but substrate surface remains wet requiring additional drying steps
Solution Approach 1:
The ink image is formed and dried on the intermediate transfer member before transfer to the substrate. This preliminary drying action ensures the ink is completely dry, eliminating the need for additional drying steps after substrate application and preventing smearing during handling.
Solution Approach 2:
The intermediate transfer member acts as a drying chamber where the inkjet image can be fully dried in a controlled environment before contacting the substrate. This separates the drying function from the substrate, eliminating the need for post-substrate drying steps.
4Quantity of substance
If excessive wetting of substrate occurs, then ink penetration increases, but substrate cockling occurs and duplex printing becomes difficult
Solution Approach 1:
The ink image is formed and dried on the intermediate transfer member before transfer to the substrate. This preliminary formation ensures minimal ink transfer to the substrate, preventing excessive wetting, cockling, and maintaining substrate flatness for duplex printing.
Solution Approach 2:
The intermediate transfer member mediates the ink transfer process, allowing precise control of ink deposition on the substrate. This controlled transfer prevents excessive wetting and the associated substrate deformation issues.
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 approach results in high-quality ink film constructions with improved optical density and uniformity, reduced substrate interaction, and enhanced printing performance on both coated and uncoated papers, enabling efficient and cost-effective short-run digital printing.
Implementation Method 1
using an intermediate transfer member with modified surface chemistry to manage ink spreading and drying
Implementation Method 2
The ink film constructions comprise continuous ink dots, which may by way of example be obtained by ink jetting technology
Data Source
Figure 1A~1B
Figure 2A~2C
Figure 2D~2F
AI summary
An ink film construction including: (a) a first printing substrate selected from the group consisting of an uncoated fibrous printing substrate, a commodity coated fibrous printing substrate, and a plastic printing substrate; and (b) an ink dot set contained within a square geometric projection projecting on the first printing substrate, the ink dot set containing at least 10 distinct ink dots, fixedly adhered to a surface of the first printing substrate, all the ink dots within the square geometric projection being counted as individual members of the set, each of the ink dots containing at least one colorant dispersed in an organic polymeric resin, each of the dots having an average thickness of less than 2,000nm, and a diameter of 5 to 300 micrometers; each ink dot of the ink dots having a generally convex shape in which a deviation from convexity, (DCdot), is defined by: DCdot = 1 - AA/CSA, AA being a calculated projected area of the dot, the area disposed generally parallel to the first fibrous printing substrate; and CSA being a surface area of a convex shape that minimally bounds a contour of the projected area; wherein a mean deviation from convexity (DCdot mean) of the ink dot set is at most 0.05.