What is laser cutting?
Laser ray; It is created in installations for carbon dioxide lasers by applying an electric current to carbon dioxide. In addition, to further improve efficiency, the efficiency is increased by 1/3 by adding nitrogen gas and helium to carbon dioxide gas. The cutting process performed on various machines using the resulting laser beam is called laser cutting.
With the ease of obtaining the laser beam, the fields of application have thus increased. The biggest reason for manufacturing with laser cutting is to minimize manufacturing errors and enable automation. The fact that it can be easily used in engineering and industry has greatly increased the interest in laser cutting. Through the use of laser in various stands, production can be carried out 24 hours a day, and the cost is reduced by ensuring mass production.
This relieves tools and molds of cutting operations performed by laser cutting. Since the workload is shifted to the machines, the number of errors caused by human error is indirectly reduced. There are many laser cutting methods such as contract cutting, wood cutting, CNC cutting.
Nickel alloys, steel, chromium, titanium, stainless steel, aluminum and its alloys and other materials can be cut. In addition, thanks to the benefits provided by Autocad, cutting is completed in a shorter time, and parts can be cut in sets at the same time.
What is laser marking?
If we need to briefly define the marking process, we can define it as a variation of the engraving process.
Areas where laser marking is used
This is an innovation that laser marks many materials (metal, plastic, hard metals, wood, etc.) quickly, efficiently and silently. With laser marking, we apply almost all types of letters, numbers, 2D codes, symbols, barcodes and logos
Our laser marking system enables 2D and 3D marking of medical devices in the medical industry with a resolution of 5 microns. Our labeling technology serves many industries such as medical, automotive, mould, electronics, advertising, engineering, etc. We provide fast and quality service in many sectors.
Benefits of laser marking
The laser marking process has become the choice of manufacturers in many sectors because the laser marking process gives a special quality to the applied material, it is a visually clean and bright process.
Laser cutting technology
After it became easier to receive a laser beam, the areas of its application also expanded. Its use in engineering is in the form of welding, cutting and drilling. Laser manufacturing enables automation and reduces manufacturing errors. By applying the laser to various machines, production can be carried out 24 hours a day, and the cost is reduced by ensuring mass production. Especially thanks to the laser cutting processes, many molds and apparatuses have been saved. However, due to the use of machines, human error is also very rare despite such intense energy.
With various programs, especially AutoCAD, production is accelerated and many parts of the same thickness can be cut at the same time. In this way, parts intended for use in the same place can be cut into sets at the same time.
In carbon dioxide laser benches, the laser is created by applying an electric current to carbon dioxide. In addition, the nitrogen and helium gases used are added to the low-efficiency carbon dioxide laser, increasing efficiency by 30%. Laser mixing ratio CO/N=0.81, He ==> 1 (2.3). The laser beam travels about 10 m2 through the glass tubes in the resonator section of the workbench. When the gas passes through these tubes, an electrical current flows between the two ends and a laser is created. Since the laser is a beam, its direction can be changed using mirrors. Finally, the laser beam reaches the cutting head where the cutting process is performed. The distance from the gas cylinders used for laser forming to the machine should be no more than 10 m. The working pressure is 6-10 bar.
Most industrial lasers require the use of special gases to generate the laser beam. The quality and choice of gas directly affects the reliability of the laser and the efficiency of the process. Laser gases are typically high purity specialty gases. Laser gases are fed into the device in separate test tubes or pre-mixed in certain proportions.The process parameters (gas flow rate, pressure purity, etc.) for such premixing or gassing in individual tubes are determined by the manufacturer of each laser machine and are given for the machine under these conditions.
The gases that make up the carbon dioxide laser:
- Carbon dioxide,
- Nitrogen
- Helium.
Some gases may contain 4 or 5 components. (In addition to CO, N and helium, CO, H and Ne can be added to the environment)
The layout of the laser machine and proper installation are very important. In order for the laser machine to work at maximum efficiency, the sheet materials used must be of good quality. Rusty or unevenly bent materials reduce cut quality. Otherwise, welding will occur on the surfaces. The distance between the parts placed on the sheet must be at least the thickness of the sheet. The minimum hole diameter is 8 mm for circular cuts that must be made by moving in a circle. For straight drilling, hole diameters should be half the thickness of the sheet metal. To drill holes of greater thickness, the diameter of the holes should be half the thickness of the sheet. For drilling of greater thickness, only marking is done.
In the CAD (computer-aided design) phase, you can develop a model of the workpiece and make a production drawing. Creating production drawings of a workpiece using AutoCAD software provides great convenience. Drawings can also be made using laser table programs. If the drawing is made in AutoCAD, it is created as a .dwg file and there should not be more than one layer in the drawing. This drawing is later saved as a .dxf file in AutoCAD. The workbench program is converted to a drawing (convert) using routines and converted to a .geo file for use in the program. If the drawing is made in a workbench program, it can be saved as a .geo file without the need for them.
After these processes, the workbench program is started and a plan is prepared for the placement of the part or parts to be cut on the sheet metal sheet. A certain number or more than one piece of one piece can be placed on a slab of known dimensions, provided that their thickness is the same. This method is suitable for parts cut in a set. The pre-prepared .geo file or files are called up and placed on the sheet metal in the desired quantity and variety. Then the cutting rule is defined. In the CAM (Computer Aided Manufacturing) department, the modeling of cutting one or more workpieces is carried out using a program. This evaluates the various errors that may occur during cutting. For example; If the hole diameters are too small, the laser beam comes from different places, or if the parts are too close, the distance between them changes.
In order for the operator to carry out operations and intervene in any problem, the operator is issued on paper an operator application sheet (Operator Setting Sheet) and the movement of the laser cutting head. For a program compiled on a page prepared for the operator, the program number, date, type, weight and dimensions of the material, how many sheets will be cut, total cutting time, cut length, part file names with the .geo extension are indicated. or parts to be cut out, and the page name is indicated. In addition, information such as the program number, cutting time of this part, cutting length of this part, its weight, and the number of points it will penetrate into the part is displayed.
Once the sheet material is entered, the parts are placed and the thickness, weight of the sheet metal plate, and lens size are determined. The cutting time of the process with a laser machine is also instantly visible. If too many cuts are to be made from a program created on the machine, this can be done by repeatedly calling it.
Glass partitions should never be opened after the bench has started working. These glass partitions are made of materials that protect against radiation and laser beam effects on the eyes and skin. The need for air in the bench is provided by a compressor. In addition, the environment in which the workbench is located must be clean. Using the computer on the laser stand, you can call up programs, perform operations, and view current operations.
For parts whose technical drawings are drawn, two different types of programs can be created. The first of these is a program consisting of parts. Generally, this program is preferred for parts that will be produced with a smooth shape and in large quantities. Only these parts are placed on the entire sheet metal plate. Problems can be seen by simulation in the program. The movements of the laser head on sheet metal can be changed. You can see the laser entry points into the sheet metal, the laser paths during cutting, and the out-of-process movements of the laser head. All appear in different colors. The dotted areas represent the first laser entry points, the rectangular areas represent the laser cutting areas, and the zigzag lines represent non-working movements of the laser head. This way you can see where to restart the laser in case of any problems with the printout. This simulation is also available on the computer screen at the workbench.
The sheet metal plate can be placed on the workbench by hand, forklift or vacuum cleaner. There are two cars on the counter. While the sheet placed on one of these machines is being processed, the sheet material to be processed is placed on the other. While the finished car is being taken out, another car is being taken out, which will be processed. This saves a lot of time. Thus, while the cut pieces are collected, the hair on the other machine begins to be processed.
The part shown above is drawn with AutoCAD, and the laser head movements are done with the software after the above operations. The cutting process can then be carried out on a laser stand.
The second is a program created by placing more than one part or part on sheet metal. With this program, other small parts can be placed between asymmetrical parts or at the edges, and programs can be made to produce the least amount of material waste.
Laser cutting tables, which have been imported into our country as a technology machine in recent years, provide great convenience for the production of the automotive industry. Various factories operating in the automotive sub-sector have significantly changed their competitors by using laser cutting machines. In the study, the general characteristics of the laser workbench, the possibilities provided by the use of the laser workbench, the materials and thickness of the laser workbench, which should be considered when drawing up a part program, as well as the programming steps of the production process. indicated. Explanations were given on what to pay attention to when programming on a laser machine, as well as for more efficient application and understanding of the program phase.
One of the disadvantages of products made on a laser cutting machine is the hardening of the material in parts, where the hole drilling process is performed in one blow. If these parts are expected to be manufactured using processes such as threading, etc., the program should be revised to ensure that the parts to be drilled are only marked and not drilled in one blow.
To use a laser machine, you need to have a good understanding of the structure and features of the machine. The processes from placing the material to be cut on the workbench to lifting the cut pieces must be carefully carried out. To be able to program, you need to know the program of the machine well. Also, programming can be done much easier with knowledge of AutoCAD.
