High-Viscosity Acrylic Coating for Digital-Printable Bookbinding Cloth

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Solution Overview

Problem

Current digitally printable cloths for bookbinding and printing do not achieve the same level of image reproduction, resolution, and color vividness as digital prints on paper, often resulting in imperfections like white dots and cracking due to inadequate ink adhesion and primer quality.

Innovation Solution

A fabric treated with a specific acrylic resin-based coating paste of high viscosity (7500-12000 cps) applied using air knife technology, combined with pre-treatment processes like desizing, optical whitening, and pore closure, to enhance ink adhesion and surface receptivity for HP INDIGO digital printing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional primers and coating methods are used on fabric, then the fabric can be printed with digital printers, but the image reproduction quality, resolution, and color vividness are inferior to digital prints on paper

Engineering Contradiction:
Improveimage reproduction qualityVSAvoidink adhesion
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent changes the viscosity parameter of the coating paste to at least 7500 cps (preferably 8000-12000 cps), which is significantly higher than conventional primers. This high viscosity prevents the paste from penetrating fabric pores during coating, creating a smooth surface layer that enables high-quality digital printing while maintaining reliable ink adhesion through the polymerization process at 200°C

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite coating system consisting of an acrylic resin-based paste combined with specific additives including non-silicone anti-foaming agents and polyurethane-based flow controllers. This composite formulation creates a homogeneous layer that provides both excellent surface quality for digital printing and strong ink adhesion properties

Inventive Principle:
Principle #40Composite materials

2Productivity

If liquid inks from digital printers are applied directly to fabric, then the printing process is simple and fast, but the inks do not adhere well to the fabric surface

Engineering Contradiction:
Improveprinting speedVSAvoidink adhesion
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies a high-viscosity acrylic resin-based paste to the fabric before printing as a preparatory step. This preliminary coating creates a receptive surface that bonds well with subsequent digital printer inks, eliminating adhesion problems while maintaining the speed and simplicity of direct digital printing processes

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If low viscosity primer is used to coat the fabric, then the coating process is easy and economical, but the primer penetrates fabric pores causing white dots and poor coverage

Engineering Contradiction:
Improvecoating process simplicityVSAvoidprimer coverage quality
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent dramatically increases the viscosity parameter of the coating paste to at least 7500 cps, preventing penetration into fabric pores during the coating process. This high viscosity ensures complete surface coverage without white dots while maintaining ease of application through the paste's smooth consistency and controlled flow properties

Inventive Principle:
Principle #35Parameter changes

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 treated fabric achieves improved image reproduction and resolution, increased color vividness, and better ink adhesion, ensuring high-quality digital prints comparable to paper, with enhanced machinability and compatibility with various digital printing technologies.

Implementation Method 1

components that at temperatures around 200°C for less than one minute initiate the state of polymerization

Methodology Applied
Scientific EffectPolymerization: Photopolymerisation

Data Source

PatentEP3397805B1Process for obtaining a cloth with high performances for digital printing and relative cloth
Publication Date: 2019.11.06 MFR DEL SEVESO
  • EP3397805B1 patent drawingFigure 1

AI summary

A description is given of a process for preparing cloths for bookbinding with gloss or matt finish, in cotton or viscose, suitable for being printed by digital printing, said process comprising the steps of A) preparing an unfinished cloth for bookbinding by desizing, washing, treating with optical white, sizing and drying; B) pre-treating the cloth obtained from step A) by applying, on at least one of the two sides, at least one composition for the closure of the pores of said cloth so as to make the surface planar; C) on the side of said fabric or said cloth intended to be printed, applying by coating a layer of a paste having a viscosity of at least 7500 cps, preferably comprised between 8000 and 12000 cps, and drying this layer; said paste being the mixture of at least one aqueous composition containing a 35% (dry) acrylic resin and components that at temperatures of around 200°C for less than one minute initiate the state of polymerization, and of at least one nonionic thickener, preferably of the polyurethane type; and D) calendering at ambient temperature the cloth obtained from step C).