Spherical Metal Particles for Laser Marking Plastics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing laser marking and welding technologies for plastics face challenges in achieving high-contrast marking without coloration, while avoiding the use of toxic substances and expensive materials, and in preventing streaks and flow lines in transparent plastics.
Innovation Solution
The use of spherical metal particles as a laser marking agent with a specific particle size distribution, free from antimony and antimony-containing compounds, which absorb laser light to create high-contrast markings without coloring the plastics and are cost-effective and non-toxic.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If pearlescent pigments or metallic effect pigments are used as laser absorbers, then laser marking interaction is improved, but the plastic becomes colored or metallic-colored and streaks or flow lines appear
Solution Approach 1:
The patent changes the physical form parameter of metal particles from platelet-shaped to spherical. This parameter change eliminates the orientation and alignment issues that cause streaks and flow lines, while maintaining high laser energy absorption capability through the spherical geometry
Solution Approach 2:
The patent replaces expensive pearlescent pigments and metallic effect pigments with inexpensive spherical metal particles. The spherical metal particles achieve the same laser absorption function at lower cost without the harmful side effects of coloration and streaking
2Measurement precision
If high concentration of absorbers is used to achieve satisfactory contrast, then laser marking contrast is improved, but the plastic is automatically colored
Solution Approach 1:
The patent changes the shape parameter from platelet to sphere, which fundamentally alters how the particles interact with laser light and plastic matrix. Spherical particles provide high contrast markings without causing plastic coloration even at effective concentrations, unlike platelet-shaped particles
3Use of energy by moving object
If platelet-shaped metal particles are used, then laser absorption is improved, but orientation in injection molding causes flow lines and streaks
Solution Approach 1:
The patent applies spheroidality by using spherical metal particles instead of platelet-shaped particles. The spherical geometry has no preferred orientation, eliminating the flow lines and streaks caused by platelet alignment during injection molding, while maintaining effective laser absorption
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
This solution allows for high-contrast, streak-free laser marking and welding of transparent plastics with improved dot precision and cost-effectiveness, using spherical metal particles that absorb laser light effectively without causing coloration or toxicity issues.
Implementation Method 1
Both are brought about as a result of absorption of the laser energy in the plastics material... the heating of the plastics materials as a result of absorption of the laser energy in the joining region is so great that the material melts
Data Source
AI summary
The invention relates to the use of spherical metal particles, which are free of antimony and/or antimony-containing compounds, as a laser marking agent or laser weldability agent in a plastic, wherein the particle size distribution of the spherical metal particles, as determined by means of laser granulometry, in the form of the volume-averaged cumulative undersize particle size distribution, has a D99 value of <110 μm, a D90 value of <75 μm, and a D50<45 μm. The invention further relates to a laser-markable and/or laser-weldable plastic which a laser marking agent consisting of spherical metal particles, which are free of antimony and/or antimony-containing compounds, wherein the particle size distribution of the spherical metal particles, as determined by means of laser granulometry, in the form of the volume-averaged cumulative undersize particle size distribution, has a D99 value of <110 μm, a D90 value of <75 μm, and a D50<45 μm.