Dual-Laser Marking for Thin Workpiece Deformation

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Solution Overview

Problem

Existing laser-based marking technologies cause deformation in thin metal and plastic workpieces due to high-temperature processing, which is undesirable for maintaining the aesthetic appeal of marked products.

Innovation Solution

A method and system where two lasers are used to heat opposite sides of the workpiece while marking one side, minimizing deformation by synchronously operating fiber lasers with uniform parameters and configurations, including a controller to regulate the process and maintain workpiece stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high-temperature laser marking is applied to thin metal and plastic workpieces, then marking speed and efficiency are improved, but workpiece deformation occurs which deteriorates aesthetic appearance

Engineering Contradiction:
Improvemarking speedVSAvoidworkpiece deformation
Core Design Contradiction:
ProductivityVSShape

Solution Approach 1:

The patent applies preliminary anti-action by using a second laser to preheat the back side of the workpiece before the primary marking laser acts on the front side. This preheating creates thermal compensation that counteracts the thermal stress and deformation that would otherwise occur during high-temperature marking, enabling fast marking speeds without aesthetic degradation

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The patent changes the thermal parameters by introducing a dual-laser system where the second laser modifies the temperature distribution profile within the workpiece. By controlling the power, wavelength, and scanning pattern of the second laser, the internal stress field is altered to prevent deformation while maintaining the high-temperature conditions needed for efficient marking

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If single-sided laser marking is performed on thin workpieces, then process simplicity is maintained, but uneven heat distribution causes workpiece deformation

Engineering Contradiction:
Improvemarking process simplicityVSAvoidworkpiece structural stability
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The patent transitions from single-sided to dual-sided laser application, adding a spatial dimension to the heating process. The second laser targets the back side of the workpiece, creating a three-dimensional thermal field that distributes heat more evenly through the thin material, thereby preventing deformation while maintaining process simplicity through automated dual-laser coordination

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 effectively prevents visible deformation in thin metal and plastic workpieces during marking, ensuring the quality and appearance of the marked products.

Implementation Method 1

heating the opposite sides of the workpiece to be treated while marking one of the heated sides

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 2

The industrial market place has been in need for a way to easily mark metal and plastic with unique identifiers

Methodology Applied
Scientific EffectHeat treatment: Heat Treatment

Implementation Method 3

Fiber laser annealing creates a permanent mark induced by heat without removing or compromising the material

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentEP2704872B1Laser-based marking method and apparatus
Publication Date: 2020.07.15 IPG PHOTONICS CORP
  • EP2704872B1 patent drawingFigure 1

AI summary

A method for marking a thin workpiece is designed to prevent deformation of the workpiece. A plurality of lasers are opposed to respective opposite sides of the workpiece so as to both sides are heat treated. The lasers can operate synchronously with the respective emitted beams aligned wit one another. As a result, the workpiece does not exhibit signs of deformation upon the completion of the marking. The workpiece is made either from plastic or metals and has a thickness not exceeding 2 millimeters. The lasers each are configured as either a fiber laser or a gas laser. The marking can be performed by lasers which are configured uniformly or non-uniformly and includes annealing, engraving and ablating. The marking can be performed synchronously or sequentially. The multi-surface marking could also be used to cause "distortion of the surface in a more controlled or desired fashion.