RGB Laser Marking of Carbonizable Polymer Substrates

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Solution Overview

Problem

Existing methods fail to create tactile markings with variable color and high detail on easily carbonizable polymeric substrates like polycarbonate, which are secure, durable, and resistant to interference, while maintaining the emboss effect and brightness.

Innovation Solution

A method using computer-controlled RGB or IR lasers to apply relief markings with emboss effect by varying laser power for color and height, creating punctual protrusions that correspond to pixels in a graphical marking, ensuring the marking is an integral part of the substrate and difficult to alter without damaging it.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If laser engraving is used to create tactile markings on polycarbonate substrates, then the marking becomes visible and tactile, but the marking turns black and loses brightness

Engineering Contradiction:
Improvetactile marking detailVSAvoidmarking brightness
Core Design Contradiction:
Manufacturing precisionVSIllumination intensity

Solution Approach 1:

The patent changes the laser processing parameters by using lower power levels and different pulse durations to create tactile relief without excessive carbonization. By controlling the energy input more precisely, the marking maintains brightness while still providing tactile feedback through the embossed effect.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes the phase transition of polycarbonate from solid to foamed state through controlled laser heating. This phase change creates the tactile relief structure without complete carbonization, allowing the marking to remain bright while providing the desired embossed effect.

Inventive Principle:
Principle #36Phase transitions

2Manufacturing precision

If higher laser power is used to increase marking visibility and tactile effect, then the emboss effect improves, but the substrate degrades and the marking becomes too dark

Engineering Contradiction:
Improveemboss effect qualityVSAvoidsubstrate degradation
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent employs periodic laser pulsing with specific duty cycles to achieve the desired tactile effect. By applying laser energy in controlled pulses rather than continuous high power, the substrate has time to dissipate heat between pulses, preventing thermal degradation while still achieving the embossed effect.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent applies partial laser energy just enough to create the tactile relief and visual marking without excessive energy that would cause substrate degradation. This partial action approach achieves the minimum necessary effect while avoiding harmful side effects.

Inventive Principle:
Principle #16Partial or excessive action

3Productivity

If conventional laser marking is used on polycarbonate, then the marking is created quickly, but the marking can be altered or removed without damaging the substrate

Engineering Contradiction:
Improvemarking application speedVSAvoidmarking security
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent creates the tactile relief structure during the initial laser marking process, embedding the security feature into the substrate itself rather than applying it as a separate layer. This preliminary integration makes the marking permanent and difficult to alter or remove without affecting the substrate.

Inventive Principle:
Principle #10Preliminary action

4Adaptability or versatility

If variable color marking is attempted on polycarbonate substrates, then the marking becomes more informative, but the process complexity increases

Engineering Contradiction:
Improvecolor variation capabilityVSAvoidlaser control system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent uses dynamic laser power adjustment during the marking process to create variable color effects. By modulating the laser power levels and pulse durations in real-time, the system produces different color shades from the same polycarbonate substrate without requiring multiple laser sources or complex filtering systems.

Inventive Principle:
Principle #15Dynamics

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 high-security, easily recognizable, and durable tactile markings with precise detail and color variation, enhancing document security by making alterations impossible without substrate degradation.

Implementation Method 1

spot irradiation of the polymer substrate undergoing carbonization by means of a computer-controlled RGB or IR laser

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 2

polymer substrate undergoing carbonization

Methodology Applied
Scientific EffectCarbonization: Pyrolysis

Implementation Method 3

the beam of which modifies the polymeric substrates undergoing carbonization

Methodology Applied
Scientific EffectThermal modification: Heat Treatment

Data Source

PatentEP4209354A1A method of production of a carbonizable polymer substrate with a tactile marking in form of a relief and a secured polymer substrate obtained by this method
Publication Date: 2023.07.12 POLSKA WYTWORNIA PAPIEROW WARTOSCIOWYCH
  • EP4209354A1 patent drawingFigure 1~2(b)
  • EP4209354A1 patent drawingFigure 3~4
  • EP4209354A1 patent drawingFigure 5~7

AI summary

The present invention relates to a method for the manufacture a carbonizable polymeric substrate having a tactile relief marking with an emboss effect, in particular a data carrier substrate for documents with security features, the method comprising securing the carbonizable polymeric substrate of step b) by applying to the substrate a marking in the form of a relief with an emboss effect, by spot irradiation of a carbonizable polymer substrate by means of a computer-controlled RGB laser, the beam of which modifies the carbonizable polymer substrates at least in a part of the area, preferably over the entire area, the markings being obtained in the form of a relief with an emboss effect are obtained by creating punctual protrusions.