Understanding The Difference between Laser Marking, Engraving And Etching

Feb 13, 2020

scientific-laserLaser marking, laser etching, and laser marking have gained significant popularity in recent years because of the government and industry regulations related to clearly legible identification of products and parts. These three laser-related services are used extensively these days as permanent marking solutions to make different products and parts distinctly identifiable.

The technologies behind laser engraving, cutting, and etching appear to be quite similar. However, there are quite a few differences between these three processes. These differences mostly relate to how they mark a surface, including how the laser functions to alter the appearance of the surface.

The surface of the material is discolored during the process of laser marking. However, laser engraving and etching mark the surface by removing a part of the surface. Between engraving and etching, there is a major difference in terms of depth of surface penetration by the laser.

Let us now take an in-depth look at each of these processes to understand how they differ.

laser-machine

Laser Marking: In this process, the laser beam only makes a slight alteration to the properties or appearance of the surface material.

  • This involves slowly moving a low-powered laser beam across the material to create high-contrast marks without causing any disruption of the material.
  • Interaction between the laser and the material results in oxidation below the surface and the material is turned black.
  • In order to anneal the surface, only low temperatures are applied to metals.
  • The entire surface remains intact throughout the process.

Mentioned below are the ways laser marking differs from laser engraving and etching.

  • It is not as common as engraving and etching.
  • For plastic materials, it is also known as laser dark marking, laser coloration, and charring. In the case of metal, it is also referred to as annealing.
  • Coloration, carbon migration, annealing, and foaming are types of laser marking.
  • Extremely popular in the medical device industry, particularly for marking on titanium and stainless steel parts.
  • Laser markers are considered to be ideal for logos, QR codes, bar codes, etc.

Laser Engraving: This process physically removes a material surface using laser beam from a laser engraver machine. Removal of the material creates a cavity on the surface, through which, an image is displayed.

  • A high amount of heat is created, causing the material to vaporize.
  • It is a fast process where vaporization continues with every pulse.
  • An easily noticeable surface cavity is created.
  • Deeper marks can be created by repeating the same process with several passes.

Technically speaking, engraving can be referred to as a subsection of laser marking. However, it still differs from marking in many ways.

  • The most common option for creating something customized or personalized.
  • The fastest way of marking with a laser.
  • It is better to avoid engraving for safety-critical However, it can be great for parts with high wear and tear probability.
  • The engraving depth can’t be more than 0.020″ for metals.
  • Works on almost all types of surface including wood, metal, plastic, glass, and leather.

Laser Etching: As briefly mentioned earlier, this process is a subset of laser engraving and involves the melting of a material surface because of the heat generated by a laser beam. A raised mark is created by the expansion of the molten material. Unlike with laser engraving, in etching, the typical depth is less than 0.001”.

Its difference with marking and etching includes the following.

  • By changing the metals’ surface finish, etching enhances their contrast and alters reflectivity.
  • It works on plated, anodized, or bare metal surfaces, as well as ceramics and polymers.