Multi-Layer UV-Curable Ink Printing for Flat Fabric Surface Finish

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Solution Overview

Problem

Existing methods for printing UV-curable layers on fabrics used in apparel and footwear face challenges in achieving a flat surface finish due to the uneven nature of the underlying fabric, leading to irregularities and imperfections.

Innovation Solution

A process involving a printer that applies multiple layers of UV-curable ink, where each layer is partially cured to flatten the surface before the next layer is applied, using a combination of radiation events to ensure full curing and surface smoothness, allowing for the creation of a flat reference layer independent of the fabric's unevenness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If multiple layers of UV-curable ink are applied on uneven fabric, then the surface flatness is improved, but the number of printing and curing cycles increases

Engineering Contradiction:
Improvesurface flatnessVSAvoidprinting and curing cycles
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The printing process is divided into multiple sequential layers, where each layer is printed and cured independently. This segmentation allows the surface flatness to be progressively improved layer by layer, with each layer correcting imperfections from the previous layer while maintaining manageable curing cycles through optimized UV radiation parameters.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A flat reference layer is created before applying the final decorative or functional layers. This preliminary flat layer serves as a smooth foundation that eliminates the need for subsequent surface correction cycles, thereby improving overall surface flatness while actually reducing the total number of printing and curing cycles required.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If multiple printing and curing cycles are used to achieve flat surface, then the surface smoothness is improved, but the production time increases

Engineering Contradiction:
Improvesurface smoothnessVSAvoidproduction time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

A flat reference layer is created before applying the final decorative or functional layers. This preliminary flat layer serves as a smooth foundation that eliminates the need for subsequent surface correction cycles, thereby improving overall surface smoothness while actually reducing the total production time required.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The UV radiation parameters (intensity, duration, wavelength) are optimized for each printing cycle to achieve effective curing in minimal time. By adjusting these parameters, the curing process becomes more efficient, maintaining high surface smoothness standards while reducing the time spent on each printing and curing cycle.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If a flat reference layer is created before final layers, then the surface uniformity is improved, but the total number of layers increases

Engineering Contradiction:
Improvesurface uniformityVSAvoidnumber of layers
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

A flat reference layer is created before applying the final decorative or functional layers. This preliminary flat layer serves as a smooth foundation that eliminates the need for subsequent surface correction cycles, thereby improving overall surface uniformity. While it does increase the number of layers, it consolidates multiple potential correction layers into a single foundational layer.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The flat reference layer is applied specifically in areas where surface uniformity is critical, such as beneath logos or decorative elements. This localized approach ensures surface uniformity where it matters most while minimizing the overall number of layers needed across the entire fabric surface.

Inventive Principle:
Principle #3Local 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

The process effectively produces a series of flat layers that can serve as a reference for further printing, enhancing the smoothness and flatness of the final surface, improving the appearance and functionality of the printed articles by ensuring uniformity and stability.

Implementation Method 1

Each printed layer is then cured by a predetermined radiation event. The printed layers are then fully cured by a second predetermined radiation event.

Methodology Applied
Scientific EffectUV curing: Photopolymerisation

Data Source

PatentEP3411521B1Method for applying layers on fabric
Publication Date: 2021.03.24 NIKE INNOVATE CV
  • EP3411521B1 patent drawingFigure 1
  • EP3411521B1 patent drawingFigure 2
  • EP3411521B1 patent drawingFigure 3

AI summary

A process for printing multiple layers on a fabric or other material using UV- curable ink that includes a step of printing a first layer on the material and another step of partially curing the first layer. A next step includes printing a partially UV-transparent layer over the first layer and fully curing the UV-transparent layer while simultaneously fully curing the first layer.