FAQ - laser cutting, laser engraving, laser marking

Frequently asked questions about laser machines and the topics laser cutting, laser engraving and laser marking.

Where will the laser be used?

Lasers are versatile. They can be used in telecommunications, materials processing, medicine, surveying, science, analytics and so on.

What sort of lasers are there?

In materials processing, the two most common laser sources are CO2 lasers (10.6µm wavelength) and fibre lasers / Nd:YAG / Nd:YVO (1,064nm wavelength).

 

Lasermachines

How does a laser work?

A laser has a laser-active medium which (usually) also gives each laser its name. This laser-active medium can be found in a resonator. That means that it is placed between an end mirror (preferably 100% reflectivity) and a decoupling mirror. Depending on the type of laser, the latter has between 2% and 30% transmittivity. If the resonator is powered (“pumped”), the laser light is reflected back and forth between the two mirrors. As long as pump performance is maintained, the laser light will continue to be intensified each time it passes through laser-active medium and a certain percentage is emitted at the decoupling mirror. The result is a directed laser beam, (usually) with higher coherence and narrower emission bandwidth (high colour brilliance, i.e. the laser emissions are narrow-band / with only one wavelength / monochrome). Laser light is the energy form which can be focussed the best. An intensity of 10kW/cm² is needed just to melt metal surfaces.

What does the word laser mean?

LASER is an acronym and stands for “Light Amplification by Stimulated Emission of Radiation”. The stimulated emission was predicted by Albert Einstein in 1917.

How does a CO2 laser work?

A CO2 laser is a gas laser which is often used for materials processing. The laser-active medium is made up of a mixture of carbon dioxide, helium and nitrogen. The stimulation is caused be either: a) electromagnetic waves (typically 48MHz or 86MHz), which are transmitted into the resonator via antennae, or: b) via glow discharge in the gas mixture through applied high voltage (typically 20,000 - 30,000 volts).

JustLaser Laser Engraver

JustLaser Large Laser Cutter

How does a fibre laser work?

A fibre laser is a solid-state laser that has optical fibre properties. Fibre lasers are usually built for marking and engraving applications in accordance with the MOPA principle. MOPA means that a “master oscillator” (MO) is intensified using a “power amplifier” (PA). The master oscillator is a compact, passively cooled, maintenance-free laser with a typical output in the 100mW range. The power amplifier is a doped glass fibre, which is usually coiled in the laser source housing. This gives you a large amplification distance with a low construction volume. The power amplifier is provided with power by pump diodes, i.e. optically. The big benefit in comparison to “classical” Nd:YAG / Nd:YVO lasers is that each pump diode is separated spatially and mounted to its own heat sink. This alleviates the problem of high volumes of waste heat in small volumes. The light from the pump diodes is conducted to the power amplifier using fibre optic cables.

 

JustCut Metal-Laser Cutter

JustMark Lasermarker

Why are lasers dangerous?

Due to their easily focusable beams, lasers can generate extremely high intensities on work pieces. The power absorbed in a short time and in small volumes leads to an extremely high increase in temperature. If, for example, you want to cut metal, the temperature reached needs to be above the boiling temperature of the metal in question (e.g. 2,540°C for aluminium). You can guess what a temperature increase – even a significantly lower one – would do to the human body (especially the eyes). There are laser classes (1 - 4 and subclasses, where 1 = inherently safe and 4 = dangerous) to help you better assess the risks and avoid injury. Using technical protection measures (e.g. housing, interlocks, shutters, etc.) for each system, even “dangerous” lasers can be used in accordance with legal provisions and without any risks to personnel. Information is provided in the respective manual.

 

More about laser safety

Which graphics program is suitable for working with a laser?

You can easily connect to common software programs such as CorelDRAW, AutoCAD LT, Adobe Illustrator and many more by using a PDF converting tool.

What file format does a laser need?

The laser machines support various file formats. Standard vector formats such as DXF, DWG, PLT, SVG, etc. and standard raster formats such as BMP, JPG, PNG, TIFF, etc. can normally be processed.

What are the laser classes?

  • Laser class 1: inherently safe – no protective measures necessary.
  • Laser class 2: < 1mW, in the visible range, considered safe if they interact with eyes for < 0.25 seconds (e.g. laser pointer)
  • Laser class 3R: < 5mW, in the visible range (e.g. light curtains), avoid direct exposure
  • Laser class 3B: acute danger to eyes (e.g. laser in a DVD recorder), 5 - 500mW, diffuse reflection safe
  • Laser class 4: most dangerous class, danger from direct, reflected and scattered beams, plus: risk of fire

(Subclass “M” not considered here).

 

Mehr Infos zur Lasersicherheit

What is the difference between a laser cutter and a laser engraver?

Laser engravers and laser cutters are principally one device. The difference is in the respective strengths, the optional add-ons and the different wattages of the laser systems. The most suitable laser machine is decided by the primary application and the material to be lasered.

 

Laser machines

Which laser is ideal for cutting?

You can cut organic materials like wood, plastic and textiles with both the JustLaser Large Laser Cutter and the JustLaser Laser Engraver. The JustLaser Large Laser Cutter can also cut metals with a thickness of up to 4 mm. The JustCut range of products with an output of 1kW - 3kW from a fibre laser can cut metals with a thickness of up to 10mm.

Laser applications

What can I cut with a laser?

Find a list of all the materials here:

laser applications

How does Laser Cut work?

The processes used for laser cutting – laser flame cutting, laser fusion cutting and sublimation cutting – are dependent on the material. For laser flame cutting, oxygen is used as a cutting gas and as an additional energy supplier. The high temperature in the cutting gap and the oxygen start an oxidation process (“combustion”), the high process heat released from which supports the cutting process. For laser fusion cutting, on the other hand, metals are melted under the heat of the laser beam and driven out of the cutting gap by the high pressure of the process gas. This often leads to lower cutting edge quality. Cutting processes can also be carried out with high-performance fibre lasers with nitrogen inflow (less commonly, 400W with CO2). This process, in which cutting edges retain their metallic sheen, is slower than flame cutting, although cutting edges usually turn dark in flame cutting. .

 

JustLaser Large Laser Cutter

How can you engrave wood?

You can create your desired design in your usual graphics program. You don’t need any extra software or comprehensive training. The template is sent to the laser via a print command and can be put into effect quickly and easily.

What can you cut with a laser?

You can use a laser to cut materials like wood, metal, acrylic and many more. You can find a detailed overview here:

 

Laser applications

What does Laser Cut mean?

Laser Cut is simply a laser cutter. The processes used for laser cutting – laser flame cutting, laser fusion cutting and sublimation cutting – are dependent on the material from which a workpiece is made.

JustLaser Large Laser Cutter

How far can the water-cooling system be from the laser?

5m (hose length, i.e. 5m laser – cooling system + 5m return)

What does a laser cutter cost?

The cost of a laser varies due to the various wattages and the optional extras. We’ll happy to work out the price for the right laser for you. More information under:

JustLaser contact

What laser power do I need for what application?

The optimal laser output is strongly dependent on the material. Engraving wood needs a higher output than marking paper. As a rough guide for cutting processes on organic targets with a CO2 laser, you need an average power output of about 10 watts per millimetre of material. So 3mm-thick acrylic can be cut at an economically-viable speed using a 30-watt CO2 laser.

Which wood can I use with a laser engraver?

Plywood, balsa, MDF, cork, HDF, and many more. A JustLaser Laser Cutter can cut numerous types of wood without any problems – from very thin boards through to 20mm-thick boards. Properties such as density, oil content, resin content and material moisture all play a role in the final result. Using a combination of a CO2 laser cutter and a saw for quick, straight cuts makes it possible to process wooden boards in a simple and flexible way.

Which laser should I use for cutting metal?

For applications with metal, we recommend our JustLaser JustCut fibre laser. This is ideal for processing metal, sheet metal, copper and aluminum. A compact fibre laser machine equipped with nLIGHT laser sources with a laser output of up to 3kW.

Is it possible to use lasers on acrylic glass?

Acrylic is excellent to work with using a laser, regardless of whether you want to give the material a specific shape or give it an inscription. When a process is carried out correctly, the cutting edges have the same level of transparency and smoothness as all the other edges of the workpiece.

laser cutting acrylic

Is it possible to use lasers on wood?

Yes, you can engrave wood. Through laser cutting and laser engraving, you can give wood objects that “certain something”. Numerous types of wood can be processed according to your personal preferences or your customer’s wishes. Find more information about this here:

laser cutting and laser engraving wood

Is it possible to use lasers on polycarbonate?

Yes, you can use a JustLaser laser machine to effortlessly cut or engrave polycarbonate (also known under the trade name “Makrolon”). Find more information about this here:

Laser cutting and laser engraving acrylics

Which woods are suitable for engraving?

Plywood, MDF, HDF, precious wood, real wood, veneers, press boards, cork and inlays are particularly good for engraving.

Laser engraving

Can wood be cut with a laser?

The processes of laser engraving and laser cutting wood are not just used for creative designs, but also in the industrial sector. Whether it’s plywood, balsa, MDF, cork, HDF or multiplex boards, a JustLaser Large Cutter can cut numerous types of wood without any problems – from very thin boards through to 20mm-thick boards. The extraction system must be set up accordingly, especially for thick workpieces and / or if there is a large amount of glue.n.

Which laser should I use to cut wood?

The JustLaser Large Laser Cutter is particularly well-suited to laser cutting wood. Find more detailed information about this here:

laser cutting and laser engraving wood

On which materials can lasers be used?

You can use a laser to cut, engrave and mark materials like wood, metal, acrylic and many more. You can find a detailed overview here: 

 

Laser applications

Is it possible to use lasers on polycarbonate?

Yes, you can use a JustLaser laser machine to effortlessly cut or engrave polycarbonate or Makrolon. Find more information about this here: 

laser cutting and laser engraving polycarbonate and acrylic

Is it possible to use lasers on polystyrene?

Yes, it is possible to quickly and easily use lasers on numerous foam materials – including polyurethane, polyethylene and polyester.

laser cutting foam

Which laser should I use for engraving?

Wood, acrylic, fabric, metal and many more – the laser engraver is the ideal entry point into the creative, productive and profitable world of laser engraving. Fibre lasers like that in the JustMark Lasermarker can mark and engrave virtually any metal – as well as a number of non-transparent plastics.

How strong does a laser need to be to engrave metal?

Metals are engraved using fibre lasers. An average power output of 20 watts should be sufficient. The pulses need to be short and the peak pulse power needs to be in the range of several kilowatts. Laser sources (with a suitable beam guide and focussing lens) have been installed at the JustMark Lasermarker workstations for exactly this purpose.

You can engrave metal with a CO2 laser if you apply a special paste (e.g. Thermark) to the metal workpiece beforehand. This paste is then “burned in” to the metal thanks to the high, laser-induced temperature increase. That makes the inscriptions very robust and durable.

How does laser engraving work?

In contrast with mechanical engraving, where material is removed through scratching, piercing or chiselling, laser engraving is carried out with the help of the energy of a laser beam that heats the surface. Either up to evaporating temperature – at which point an engraving emerges – or well below it – at which point the wood reacts with the oxygen in the air and (usually) turns a dark colour.
Laser engraving

With laser engraving, a digitally-controlled laser engraver heats up the surface of a work material so much that it evaporates to a certain depth, creating a permanent and abrasion-resistant engraving. The smart laser technology in the JustLaser Laser Engraver wins people over due to its top levels of accuracy with repetitions without the need for an additional tool or any special technical skills.
Ablating

White marks can be made on anodised aluminium using CO2 lasers and fibre lasers. Setting the parameters for this is very simple. The chromophoric metal salts are thermally corroded by the rise in temperature, meaning that the inscription is white. Naturally anodised aluminum (i.e. with a metallic sheen but without any colour) and bare aluminium can be given dark or light inscriptions. With anodised aluminium, the extremely mechanically tough, chemical-resistant and non-electroconductive layer of aluminium oxide is retained.

With painted metals or plastic laminates (at least 2 layers), the coat of paint or top layer of plastic can be removed using a CO2 laser, often without leaving any residue behind.

Laser Engravers

How does a marking laser work?

A so-called “galvo laser” is used in marking lasers. It beams onto 2 rotatable mirrors with low inertia which are positioned at 90° to each other. The mirrors are positioned precisely by powerful servo motors. The high dynamics of the motors in combination with the low rotational moment of inertia of the mirrors typically result in five to fifty times the output of plotter systems. However, galvo systems are usually restricted to a small processing field (in comparison to plotters).

How strong does a laser need to be to cut metal?

The wattage to use depends on the properties of the respective material and the thickness of the metal plate. Aluminium up to 1.5mm thick, stainless steel up to about 3mm thick and construction steel up to just over 4mm thick can be cut with CO2 lasers with 400W laser output and oxygen inflow.