Laser marking of fruit and vegetables

Many people ask us if metals can etch with their CO2 machines. And the answer is, yes, it is possible to engrave metals with a CO2 machine. And with a process of applying special paints that react chemically at the time the machine does the engraving. But it is not the best way to do it and it is not the cheapest way. In this blog we will explain the best way to engrave metals.

What kind of chemical can I use to burn metals with CO2?
There are several types of chemicals that use for the marking of metals in CNC CO2 machine, the most recognized are: Cermark, Thermark, Enduramark and LaserBond 100. Being Cermark the first brand to know for marking metal in laser machines. All and each one has a solution for the engraving of metals, either in the form of paste to apply on the metal, from formula to prepare and apply to spray cans. This type of chemical solution is one of the best but its price is quite expensive, however its finish. And its speed of both drying and working  not as optimal as the engravings that can make with fiber optic laser machines.

1) The types of metals that I can engrave.

There are several types of metals to engrave. But the most common metals to engrave on a CO2 CNC machine are: Stainless steel, Steel, aluminum, some anodized metals, copper and brass.

These metals being the most common to work and the best results obtained in the final work. Although there are more types of materials and other types of alloys in which the final result is not going to be optimal or directly can not record as per example silver gold among others.

2) Certain metal materials can etch directly without chemicals

Metals such as anodized steel and aluminum, are the very common metals found in P.O.P advertising items such as pens, USB drivers. And even some cell phones, among other anodized metal products. These metals have a paint that can be removed with the CO2 Laser machine. But they have the limitation of the base color, since the laser machine can remove a large amount of paint but cannot remove all the paint. This generates that the work done with the anodized metals are left with a small case of the color of the material. For example: assuming that we are going to engrave a dog plate in red anodized aluminum, after having engraved it. The name of the dog and all the contact details of the owner are going to Having a reddish color throughout the recorded area. Therefore the engraving will not have a totally clear and clean effect.

3) The best metal to burn with CO2 is steel

Stainless steel is the best material to work engraved on a CNC CO2 machine, since this material has less capacity of thermal coefficient compared to aluminum. This means that the light beam not reflect as if reflect by aluminum. When the beam of light generated by the machine not reflect, it means that it stays longer in the metal. So it can burn with a darker color and better quality.

Is there another cheaper way to burn metals with a CO2?

On this question there are many answers and many suggestions of what type of chemical can use. But not all of them are effective and you can run the risk that the machine does not etch the metal or that the machine suffers damage due to reflection of the Do in the lens. One of the products use to engrave metal in a cheaper way is the CRC Dry Moly Lube. This chemical which is a dry lubricant for high friction parts, works in a fairly good way on stainless steel. But does not work in the same way on aluminum, copper or brass as its similar chemicals created specifically for engraving on metal. The brasso also use as an alternative, which is a metal shine. These two options normally use as alternatives to “Official metal engraving chemicals”. It should remember that its use to engrave metal is only on stainless steel. Since other metals such as copper when cleaned or with alcohol, the engraving easily comes out of metal.

Can you erase the engraving over time?

A well-engraved metal engraving with the correct working parameters. And the correct material does not have to erase from the metal. Even a chemical etching on a smooth metal should not  erase. Even if the chemist is a non-„official“ one the CRC Dry Moly Lube (in stainless steel). Because the engraving on the metal is usually an engraving with a slow speed and a tube power considered high. The only way to erase an engraving on metal, is by passing a sandpaper to polishing metal. This being the only really effective way to erase or fade an engraving made on a CO2 machine with chemical process.

Parameters are also very important.

Returning to the previous point and especially the fact that the metal has reflective capabilities. One of the secrets for a better result correct engraving parameters and a clear and good design. But above all a good parameter setup makes a big difference. Between an engraving on metal that erase in a very easy way to one that not erase from the metal, the latter even applies to low wattage machines.

In this infographic we want to show you the different work tables types that exist in the laser engraving and cutting machines that we have, as well as the advantage of each of them according to the material or application that you want to work.

ASPIRANT TABLE

The flatness of the table to achieve a quality result is the most important. If, in addition, it incorporates grooves for fastening by vacuum, it will allow us to easily fix the material, especially the thin ones such as paper or sheets. Adjustable lower and upper suction.

ALUMINUM BARS

The purpose of these slats is that when cutting the material, it suspend, and the laser beam does not find obstacles in the cut. The bars can relocate depending on the material to work, in addition to supporting more load weight.

STANDARD TABLE

Table with millimeter margins, completely flat to record all kinds of materials. It also has automatic height adjustable for greater adjustment of the focal length, which translates into high quality results.

BEE PANEL OR SQUARE GRILLE

This type of tables, with metal structure, helps to work with fine paper / cardboard, marquetry, textile, leather, etc. These materials remain flat on the entire surface, in addition to preventing the detachment of small remnants.

CUTTING TABLE WITH DRAWER

Exclusive accessory for the GCC Laserpro range. This drawer allows the standard table to be adapted to a cutting table, with lower suction. The position of the movable supports with magnetic base can modify, so that it adjusts to the needs of the cut, avoiding the reflection of the laser beam. The great advantage of this table is that the cutting grid can place on the top, leaving it in an aspirating mode, thus fixing the material to work.

A laser cutter, through the technology used for its operation, offers a wide range of cutting possibilities in a wide range of materials. When using this machine there are practically no limits on designs in cuts, being able to make very complex cuts with great precision quickly. So the time and money invest in the production of pieces of different characteristics is less than if we use other tools cutting

To understand the operation of a laser cutting machine it is necessary that we first define what a laser cutter is.

A laser is a device design to concentrate a light beam at a specific point; It consists of a pair of mirrors, an active medium that allows amplifying the light (in solid, gaseous or liquid state) and a beam of light or electric current that will give energy to the active medium. The name of this device is light amplification by stimulate emission of radiation, laser for its acronym in English (Light Amplification by Stimulated Emission of Radiation). And today has many industrial, medical and telecommunications applications.

The laser is usually locat on the back of the cutting machines and emits a beam of light towards a series of mirrors that are responsible for reflecting the beam to the laser head where the light will direct down. Before the light leaves the machine, it goes through an active medium that is responsible for amplifying the beam. In CO2 machines, carbon dioxide is the medium that performs this task. While in other equipment a neodymium dope yttrium aluminum garnet lens (Nd YAG) use to amplify the light beam.

The materials with which these equipments manufacture can vary. And although the best mirrors and lenses with which they can equip are of diamond and gold. Due to the high costs of these materials it is rare that they use. Instead, silicon mirrors and zinc or germanium selenurium lenses use, which are as resistant and effective as gold and diamond.

As we mentioned, a laser cutting machine allows complex designs to achieve with high precision. This is because the laser has the ability to move along any path at high speed.

In addition, depending on the cutting power of the equipment, various medium density materials can cut. These equipments currently have an automated operation thanks to the CNC (numerical control by computer) that allows. In addition to maintaining a constant distance between the surface of the material. And the light emitter, to program commands that control the speed. And the design to follow according to the needs of each cut and material.

To cut the materials the laser concentrates the light beam on a point that vaporizes by thermal energy. For this reason, some people have the belief that using a machine of this type can damage the materials by heat.  However, thanks to its precision, the heat directe only to the point that you want to cut at a high speed. Which is why There is no risk of damaging the part if the equipment use correctly.

At this point it is important to mention that although a laser machine is simple to control. It is necessary that the person who operates it receives training from a specialist to use the equipment. Which will prevent damage to the machine and cutting materials. And will contribute that the user is safe and can take full advantage of the equipment.