CO2 Laser Cutting Engraving Machines
General information on CO2 laser machines
A CO2 machine is a type of CNC (computer numerical control) laser machine. To generate a laser beam, this machine is equipped with a tube filled with a gas mixture, the main one being carbon dioxide (CO2).
In order to understand the configuration and operating principle of the machine, let us look at its main components.
What does a CO2 laser machine consist of?
Bed. Sometimes it is called a frame. It is the basis of the entire structure. The quality of the final product, produced on the machine, and the durability of the equipment depend on its bed rigidity and stiffness.
When processing material, vibrations occur that negatively affect the positioning of a laser beam. The sturdy and tough bed absorbs vibrations providing stability to the machine.
The machine bed can be cast or collapsible.
Laser tube. It is the main tool of the CO2 machine that acts as a laser source. The tube is designed as a sealed glass flask comprising several containers. One of these containers is filled with carbon dioxide with a small amount of nitrogen and helium. Sometimes, a mixture of xenon and hydrogen can be added.
The main task of the laser tube is to generate a laser beam that is formed due to reactions caused by an electrical impulse. For more details, please check the next section.
Gantry. Usually, a gantry is made from aluminium, and the thicker the alloy is, the less deformation will occur in case of fire.
Optics. As a rule, an optical system of CO2 laser machines consists of two basic elements: reflecting mirrors and a focal lens. The main task of the mirrors is to transfer the power of laser radiation. They transfer a generated laser beam from the laser tube to the focal lens that is located on the traveling cutting head of the machine. The beam passes through the lens and onto the material.
The mirrors have fixed sizes; most often, their diameter is 20-25 mm. The focal distance and diameter are the main parameters for the lens.
Guide rails. This part of the laser machine looks like a rail. Its main task is to move the working tool smoothly.
Manufacturers produce CO2 laser machines with 3 types of guide rails:
- flat guides;
- round-bar guides.
Rolling guide rails are usually installed on small-sized machines.
Engines. As for laser machine engines, the following types should be mentioned: 2 and 3-phase stepper motors and servomotors. 3-phase motors differ from their predecessors by having a larger number of teeth. This results in a smaller number of steps and ensures the engine accuracy.
Servomotors are characterized by high speed and positioning accuracy. Such engines successfully combine high power and compact size.
Control system. All CNC laser machines have a computerized brain. The controller allows you to control the machine with programs you set up. Programs are created for each type of machining. They contain the future product layout and the coordinates on which the machine working head will be moved.
The controllers are compatible with different software. The machine can be controlled by means of a personal computer or a console.
Chiller. As a rule, a basic version of a CO2 laser machine includes a water pump that is used to cool the components with water. However, for the machines with the laser tube power more than 80 W, it is recommended to install an additional cooling system, or chiller. It guarantees longer service life of the laser tube.
How does the equipment work?
Now, as we know the machine’s design, let us move on to its operating principles. As mentioned above, the laser beam is the main working tool of the CO2 machine. It is formed inside the laser tube that contains a gas mixture. The supply of electricity excites the nitrogen molecules activating the transfer of energy to the carbon dioxide molecules. The charged particle triggers the production of a photon, which encounters another activated molecule and causes a process of creating another photon. Thus, the tube is filled with a large number of photons.
Some of the particles created inside the tube pass through a translucent mirror and hit the lens that collects them into a straight beam. The rest of the particles stay inside the tube to generate new photons.
All photons in CO2 laser equipment have the same wavelength. Their motion is always parallel. For this reason, the radiation does not diffract, but a laser beam with high energy and small radius is formed.
Passing through a lens, the laser beam is focused on the surface of the workpiece. Because of the high temperature, its particles start melting and evaporating. With the CO2 laser machine, the following types of treatment can be done:
When cutting is performed, the material melts very fast because the beam works in depth. While during engraving, only the surface particles of the workpiece are vaporized.
The CNC laser machine is controlled programmatically. After the reaction in the laser tube takes place, and the laser beam is generated, the machine controller starts to work. An operator downloads files with layouts of future products and coordinates according to which the working head will move. The files with layout are created in advance using a special software, for example Corel Draw, LibreCAD, etc.
Advantages of CO2 laser machines
CO2 laser machines have already been used in different types of production for several decades. Therefore, these machines are technologically optimized as far as possible and adapted to the tasks required by modern standards.
CO2 lasers are characterized by:
- a wide range of dimensions (from tabletop to large-format models);
- an affordable price (especially, compared to fiber optic equipment);
- a short payback period;
- a high quality machining result with perfect edges;
- no solid waste;
- functionality that allows you to perform several types of machining on a single machine;
- a wide choice of suitable materials (paper, wood, fabric, plywood, acrylic, etc.);
- high productivity at low energy costs;
- no risk of product damage (if the machine is used properly);
- reliability and durability.
When purchasing high quality equipment and performing maintenance timely, you can be sure that the machine or its components will not fail for a long time.
What material is suitable for CO2 laser treatment?
CO2 lasers can machine a large number of non-metallic materials. Most often, these machines are used to process wood and plywood. However, the list of suitable materials also includes:
- fabric and fur;
- leather and faux leather;
- ceramic, and etc.
Note that despite some materials being treated on CO2 laser machines, it is not recommended to do that. For example, vinyl (during processing, chlorine is released, which adversely affects the condition of the main machine components and is a harmful vapour for humans) and Teflon (this material releases perfluoroisobutylene gas which is hazardous to humans).
Where is the equipment used?
According to all facts mentioned above, CO2 laser machines are the most versatile equipment. Therefore, they are widely used in the following spheres:
- advertising industry (business cards, banners, nameplates, signs);
- furniture production (carcasses, upholstery, covering);
- souvenir production (caskets, key boxes, engraving on gift items);
- textile industry (lace, engraving on denim, leather, etc.);
- woodworking (carved benches, staircase handrailings, furniture);
- manufacturing items from different types of stone (tiles, monuments).
How to select a CO2 laser machine?
Many factors affect the choice of equipment for production purposes. We have compiled the most important criteria that can help you to choose the proper CO2 laser machine.
Purposes of use
An important thing that you should consider and determine is the purpose of use of your future laser machine. If your company is engaged in manufacturing single items only, then the choice can be narrowed to small-sized machines with low power.
To cut large-sized materials or for mass production, it is better to consider more professional models.
It is also important to understand whether you plan to expand your production in the nearest future. If yes, then you should choose a CO2 laser machine with spare capacity. This allows you to increase the performance of the company and to reach the next level.
Material and work area
A machine work area and power depend on the material to be processed, or to be more precise, on its dimensions and peculiarities.
According to their work area size, laser machines can be divided into 3 types:
- Small-sized (desktop, tabletop). Usually, the work area size is up to 600x400 mm. Such equipment is used for single-item or small-scale production. It is designed for home use, offices or small workshops.
- Medium-format. The work area of these machines does not outrange 1600x1000 mm. It is an optimal choice for medium-scale production. These machines can be used in workshops and production facilities.
- Large-format. It is professional equipment with a large work area (about 2000x3000 mm). Such machines are indispensable for mass production and for processing large-sized materials.
The worktable can also be chosen according to the material thickness. For example, there are machines with a lifting table option that provides easy machining of thick material.
Also, you should consider materials features when choosing a worktable covering type:
- Blades. It is intended for working with thick materials and is not suitable for processing paper, fabric or cardboard.
- Honeycomb. It is the best choice for machining textile, paper, and other thin materials.
A conveyor table is also worth mentioning. It is intended for processing roll materials.
When choosing components, it is important to consider their quality and technical parameters.
Laser tube. Its power determines speed and performance of the machine as well as the thickness of the material that can be processed. Usually it starts from 40W (desktop models) and up to 400W (large-format machines).
Ignition unit. It has to correspond to the laser tube power. It is even advisable that it exceeds it a little.
Control system. We recommend choosing modern controllers that are compatible with popular software.
Optional accessories. This can include a niche for garbage collection that sometimes is not included in the basic complete set, but is quite important as it can keep the workplace clean. Also, we should mention a chiller, or a cooling system that should be installed on all CO2 machines with 80W laser tubes and higher. This allows extending its service life.
CO2 laser equipment is indispensable for various production spheres. It is intended for:
- facilitating the processing of different types of materials;
- increasing productivity due to the high production speed and fault-tolerance;
- performing complex tasks that cannot be done manually;
- saving time, money, and energy costs.
The choice of equipment to purchase should be taken seriously, as the future of production depends on it. However, an understanding of the design and features of CO2 lasers will help in this demanding task.