Understanding Laser Cutting

Posted on: 16 March 2020

Laser cutting is a process of focusing a laser beam on a material surface to either engrave an image, words or patterns on it or cut into the material to get the desired shape or cut out. Here's what you need to know about laser cutting:

The Meaning of the Word Laser

LASER stands for Light Amplification through Stimulated Emission of Radiation. This radiation can heat, melt and vaporise materials; since it can be channelled and controlled, laser cutting is made possible.

Different Varieties of Laser Cutting

You might come across flame, fusion and remote cutting:

  • Flame Cutting

A flame laser cutting method utilises oxygen as an assist gas to increase energy input through the creation of an exothermic reaction (a reaction that releases energy).

  • Fusion Cutting

A fusion laser cutting method utilises nitrogen, which is an inert gas used to mainly remove any molten material from the kerf (the cut surface).

  • Remote Cutting

The remote laser cutting method does not utilise any gas. It is mostly used for thin sheets because it partially ablates the surface of materials.

CNC (Computer Numerical Control)

Laser cutting cannot be guided by human hands; if this was the case, many mistakes would be made leading to a waste of resources. That is why CNC is used; the design of the cut is fed into a computer and then the computer handles the rest. Precision is crucial during laser cutting.

What Materials Can Laser Cutting Cut?

Laser cutting can be used on stainless steel, brass, titanium, aluminium, wood, cardboard, thermoplastics, etc.

What Makes Laser Cutting Suitable to Cut the Materials Mentioned Above?

Some factors have to be considered; for example, how does heat affect the material? Does it melt too much in such a way that the desired result cannot be achieved? Does the material catch fire? Does the material emit too much smoke or discolour? Does the material to be cut emit any harmful gases when heated?

The answers to these questions help determine which materials can be cut using laser cutting and which ones cannot.

Materials That Cannot Be Cut Using Laser Cutting

PVC, polypropylene, polystyrene, fibreglass, foodstuffs, polycarbonate, ABS, epoxy, etc. Such materials either catch fire or produce poisonous gases or smoke.

An Important Note

Laser cutting should only be done by a competent, qualified, licensed and experienced laser cutting specialist. He or she has to be able to choose the right method for the particular material being cut and be able to monitor the cutting process. Dealing with hot materials is also risky and care must be taken.