The Lowdown on laser Engraving

Laser Engraving has evolved dramatically over the previous decade or so. When I started working in this business, if you needed to have a laser at your manufacturing facility or shop it’s important to have THREE THINGS: Highly Trained Personnel, Patience and very DEEP pockets.

In the previous 10-years or so, computing power, solid-state lasers and deployment of advanced software has helped to drop the prices considerably, the required skillset to own and operate a system is also quite low and improved reliability means that system maintenance has become significantly simplified.

So, let’s get to the meat of this Article.

Laser MARKING: TIPS and TRICKS

1. First and Foremost, ensure you have the correct Wavelength!

The Wavelength of the laser is critical to laser etching.

ORGANIC MATERIALS:

For example, Let’s say your major business is custom firearms. Most people begin with a simple CO2 laser having a Wavelength of 10,600nM. These are low-value, low-barrier techniques meant for engraving and marking organic materials. Wood, Paper, Glass and Stone to name a few. A CO2 laser is a GREAT selection for engraving and marking the Wood Butt Stocks and Polymer Grips of guns, but isn’t going to do a lot in the way in which of engraving the steel parts of the firearm.

METALS:

In order to successfully mark and engrave with any depth in metals, we need to change the wavelength. Here, the appropriate wavelength for MOST common metals is about 1uM. Why do I say about? Simply put, there’s a number of variations  for the 1uM laser, generally clumped together as the ever-present “YAG”. In reality, the YAG is the Nd:YAG with a central emission of 1,064nM. But then there’s the Nd:YVO4, the Nd:YLF and the mainstream FIBER laser with it is proprietary glass-doped capture medium. Each of these lasers are 1uM lasers, however they have barely different wavelengths from 1,064nM, 1,057nM, 1,070nM and so forth. Additionally, every type of laser has different pulse characteristics and that can play a serious function in the proper selection.

Why does Lens Selection matter?

You would be surprised at the number of times I have to explain the importance of optics to people. It’s a primary and required step in choosing the proper software for the job and there is a core component everyone ought to unserstand. Lets look at the basics

SPOT SIZE!

SPOT SIZE vs FOCAL LENGTH:

The Spot size of a laser is critical. Let me simply repeat that. The Spot measurement of a laser is important! Simply put, you want a certain amount of energy to do the work. Remember when, as children,  a few of us would take a magnifying glass outdoors and burn ants? Remember how as we discovered that when we adjusted the focus, the wood would just start to smolder, and because the spot became smaller and smaller near the focal point the wood would really begin to char and burn? And as we went too close in, the spot would develop once more and the burning stopped? That is a GREAT demonstration of fluence. Fluence is the time period which equates to the easiest understanding of Energy over a given Area.

In our instance above, the Sun’s power was focused (until a cloud passed by). We adjusted the Energy/Unit of Area by focusing the lens to it’s tightest focus. If you consider a pizza. When you buy a Large versus a Small pie, the diameter might double. Let’s say a Large is 20″ diameter and a Small is 10″. But you don’t get twice as much, you really get quite a bit more as a result of the diameter doubling because the AREA goes up by a factor of 4!! This is the same for the laser. If we HALF the spot-measurement we INCREASE the energy density not by twice, but by a factor of 4!!

We’ll continue this and other choice suggestions within the subsequent article, but ,for now if you would like to find out more about laser engraving or laser cutting then I suggest you visit www.krintech.co.uk

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