Anti-falsification Watermark Paper via Controlled Moisture Pressing

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Solution Overview

Problem

Conventional methods for creating watermarks in paper result in uneven fiber distribution, leading to reduced paper strength and unclear watermark patterns, particularly for highlight patterns.

Innovation Solution

A method involving drying paper to a water content of 10%-25% and pressing it with rolls or plane plates featuring convex, concave, or combined patterns under controlled pressure to form clear and strong anti-falsification watermarks, using rolls or plates with Shore A hardness greater than 99.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional methods press convex and/or concave patterns on papermaking forming wires to create watermarks, then watermark patterns are formed, but uneven fiber distribution occurs and paper strength is reduced

Engineering Contradiction:
Improvewatermark pattern formationVSAvoidpaper strength
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The invention applies preliminary action by controlling water content to 10%-25% before pressing, which optimizes the paper's physical state for watermark formation. This preliminary moisture control allows the paper to be sufficiently pliable for pattern transfer while maintaining fiber integrity and strength, avoiding the fiber distribution problems of conventional wet pressing.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If conventional methods vary partial water penetration via welding, weaving or agglutination on forming wires, then watermark patterns are created, but fiber distribution becomes uneven and areas with less fibers have reduced strength

Engineering Contradiction:
Improvewatermark pattern clarityVSAvoidlocal paper strength
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The invention applies parameter changes by controlling water content within the specific range of 10%-25% and applying pressure in the range of 50N-1.5KN/cm. These parameter optimizations enable clear watermark formation through controlled fiber compression and rearrangement without creating areas of severely reduced fiber density, thus maintaining overall paper strength.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If pressure is applied to form watermarks on moist paper, then watermark patterns are created, but the paper may be too soft causing uneven fiber distribution

Engineering Contradiction:
Improvewatermark pattern definitionVSAvoidfiber distribution uniformity
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The invention optimizes parameters by controlling water content to 10%-25% and applying pressure between 50N-1.5KN/cm. This parameter control allows the paper to maintain sufficient structural stability during pressing, enabling clear watermark formation while preventing excessive fiber displacement and maintaining uniform fiber distribution.

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 method produces watermarks with smooth, continuous transitions between light and shade, improving clarity and maintaining paper strength by avoiding uneven fiber distribution.

Implementation Method 1

pressing partial or full surface of the paper by rolls or plane plates with convex patterns, concave patterns or combination of convex and concave patterns roll to form watermarks. The pressure is 50N-1.5KN/cm when pressing the paper.

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

The surface material of one of the rolls is plastic or rubber whose shore A hardness is more than 99.

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP1975311B1Anti-falsification watermark paper and method of making same
Publication Date: 2017.05.31 CHINA BANKNOTE PRINTING & MINTING
  • EP1975311B1 patent drawingFigure 1
  • EP1975311B1 patent drawingFigure 2a~4c

AI summary

An anti-falsification watermark paper, a method of making the same and the apparatus for performing the method is disclosed. The method comprises the following steps. The moist paper is predried after shaping step. The predried paper is pressed by a dandy roll or a plate which comprising concave, bulgy or scraggy patterns in part or in full to form watermarks. The moist paper is redried after the pressing step.