Marking items for reasons of security has been a valuable security technique for many years. It is now possible to use a laser to mark almost any surface and help prevent the item from being stolen. There are two main forms of laser marking:

• Laser Marking – This is the process of leaving a marking on an item by using a laser. The marking may be printed on, melted into the surface, charred, foamed or even changed in colour. The laser will not make any contact with the product being marked; a beam of highly concentrated light will create the marking on the object.
• Laser Etching – Laser etching is similar to laser marking, but it takes the process one step further. The chosen marking is literally etched into the surface of the material and cannot be removed, it will not wear over time or change color. Again, the laser will not touch the surface of the material being etched.

Lasers can be used on almost any material but there are special materials which have been developed to enhance the markings being made. It is the same machine which creates both laser marking and laser etching.

The machine

A laser machine requires a computer to control the actions of the laser; a laser to mark the material (the laser beam is usually approximately as thick as a pencil) and surface for the laser to act upon. The majority of machine have a static platform where only the laser will move, some machines allow the laser to move in one direction and the platform in the other. There are even some machines which allow you to fasten your material to a cylinder which is rotated around the fixed laser.

The point of the laser will be no more than a fraction of a millimeter and will heat the chosen material rapidly, vaporizing the material and leave an engraved mark. This can result in fumes which need to be efficiently removed from the room. The heat generated from a laser beam will quickly heat a machine as well and a good cooling system is essential.

The machine can be programmed to etch almost any design into the material. Even the speed of the laser can be controlled as this will affect the depth of the engraving. The machine is often part of a laser table set-up which ensures the machine is incredibly accurate.

Materials which can be engraved:

• Natural materials such as wood are easy to engrave with a low powered laser. Hard paper and fiberboard are also easily marked.
• Finished leather products can be engraved using a laser and the finished product appears similar to a branded item.
• Plastic is exceptionally easy to engrave and will happily take a variety of complex designs. However, Thermoforming plastic will melt around the engraving and will not provide a clear marking. For some products this is acceptable whilst others need to use specially developed laser plastics.
• Metal can be engraved with a commercial system. For a while it was the most difficult material to engrave with a laser due to melting issues. Metal engraving lasers have been developed which use shorter wavelengths to avoid any issues.
• Jewellery is much easier to engrave with a laser machine than by hand and it has been welcomed by jewellery manufacturers.

Specific industrial applications

Fiber lasers have become popular in the last ten years; they are able to engrave almost any image clearly into flexographic plates and cylinders. Industrial lasers operate at a much higher power and are able to destroy the unwanted material completely; leaving a very clean, accurate mark. The lasers are even able to be set to only penetrate the thin opaque black layer on a specially produced photopolymer plate.

Industrial lasers are also frequently used to engrave anilox rolls, create sub-surface laser engraving and direct photopolymer laser imaging. Technology is improving rapidly and images are becoming clearer and easier to add, in the future laser marking may infiltrate many other parts of our daily lives. Until that happens, let’s just enjoy the great benefits of the technology in the personal and business environment.

Author Bio:

This content has written by Michael Clark and Fimark.co.uk!