What is laser marking?

Laser marking is a contactless, direct inscription, marking or decoration process of objects by means of a focused light beam. This process can be used to permanently process all types of materials and surfaces. The process is characterized by its versatility, high durability and flexibility. There are different types of laser marking, which largely depend on the material and surface of the object to be engraved.

Advantages of laser marking

Flexibility
Detail reproduction
Good readability
Wide range of materials
Automation
Durability
Low maintenance
No consumables

How does laser marking work?

Laser is the abbreviation for "Light Amplification by Stimulated Emission of Radiation". In order to understand how it works, one should first look at the structure of a laser.

Basically, lasers consist of three components: the laser medium (solid, liquid, gaseous), a pump source and the resonator.

  1. Laser medium: This is used to generate the (laser) light by stimulated emission.
  2.  Pump source: Excites the laser active medium, a population inversion is generated in the laser medium.
  3.  Resonator: Essentially consists of 2 mirrors between which the light particles (photons) are reflected.

Electrons are brought to a higher energy level by the energy supplied by the pump source (optical pumping). Spontaneous emission causes light particles (photons) to be emitted, which are reflected back and forth between the two resonator mirrors. These generate more and more photons each time they pass through the laser medium again (stimulated emission). This process builds up like an avalanche, resulting in a concentrated beam of light. One of the mirrors is partially transparent and allows the light beam to escape - the actual laser beam.

When the laser beam hits a surface, it causes changes in the material. A distinction is made between material changes on the surface, below the surface or a coating removal (e.g. ink) from the surface. These depend on the laser marking process, which is largely dependent on the type of material to be engraved.

Laser marking processes:

Tempering

The laser beam activates oxidation processes by heating on the metal surface, which become visible as a brownish coloration on the surface, while the surface texture remains completely intact.

Removal of a top layer

The laser uses its effect to selectively remove the previously applied layer (e.g. with pad printing). The contrast or the desired marking is created by the color of the underlying base material or base coat.

Color change: foaming


The laser melts the matrix material in a targeted manner. Gas bubbles are formed, which are trapped during cooling. They form a raised mark that is relatively wide and diffusely reflects the light. Markings on dark plastic appear bright.

Color change: Carbonizing

The laser selectively burns the carbon-containing plastic molecules on the surface. Dark gas bubbles are formed, which are trapped during cooling. The surface remains largely intact and smooth. Marking appears dark.

Melting

The laser selectively melts the surface and easily penetrates the material. Due to the low penetration depth, the coating remains corrosion-resistant. The result is a highly reflective surface providing a high-contrast white engraving on dark metals such as hardened steel. 

Material removal

The laser ablates the base material to a depth of millimeters. The metal is liquefied at specific points or converted to a gaseous state and directly removed. This is also referred to as laser deep engraving.

Glass engraving

The laser beam penetrates the inside of the glass component. Microcracks are created at specific points, which represent the desired inscription. In this way, three-dimensional structures can be engraved.

Comparison of the processes

ProcessMaterialMaterial influenceContrast
TemperingMetalStructural changeDiscoloration due to temperature-dependent oxide layer formation
Removal of a top layerPaper, plastics, metal, glass, ceramicsRemoval of an absorbent top layerColor of the underlying material
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Our laser marking processes

MOF – Mark on the fly

  • High output
  • Marking takes place "on the fly"
  • Depending on laser source – with or without pigments
  • High durability
More information on MOF technology

MOF MAXI

  • Performance increase of up to 400 %
  • High ease of use - only one laser software and one production line
  • Connection to high-speed production processes
  • Arrangement of laser heads in series or parallel
Further information on MOF MAXI technology

MOF MULTI

  • Simultaneous marking of different positions on one component
  • Simplified process - no need for time-consuming turning of components
  • High ease of use - only one laser software and one production line
  • Ideal for marking connected codes
Further information on MOF MULTI technology

EDM – Encoder Driven Marking

  • High output
  • Marking takes place "on the fly" during rotation
  • Depending on laser source – with or without pigments
  • High durability
More information on EDM technology

More technologies

About Pad Printing

About Pad Printing

Print-Laser Combination

Print-Laser Combination
Yuen Wah Lee
Your contact

Yuen Wah Lee

You have a product that you want to mark, but do not know how? I will be happy to help you!

Phone No.: +49 7150 928-310