Plasma cutting is a processing method that uses the heat of a high-temperature plasma arc to partially or partially melt (and evaporate) the metal at the incision of the workpiece and uses the momentum of the high-speed plasma to remove the molten metal to form an incision.
The CNC plasma cutter machine is matched with different working gases (the working gas is the conductive medium of the plasma arc and the heat-carrying body. At the same time, the molten metal in the incision must be removed. The commonly used plasma arc working gases are argon, hydrogen, nitrogen, oxygen, and air. , Water vapor and some mixed gases) can cut all kinds of metals that are difficult to cut by oxygen, especially for non-ferrous metals (stainless steel, carbon steel, aluminum, copper, titanium, nickel). The cutting effect is better. Due to the fast cutting speed and accuracy High, low cost, plasma cutting has been widely used in large industrial CNC applications to small hobbyist shops and is widely used in locomotives, automobiles, pressure vessels, nuclear industry, chemical machinery, general machinery, steel structure, construction machinery and other industries.
CNC plasma cutter machines are divided into working methods: dry plasma, semi-dry plasma, and underwater plasma; in terms of cutting quality, they are divided into ordinary plasma, fine plasma, laser-like plasma, etc.
The plasma cutting machines provided by our company include flat plasma cutting machine, plate and tube integrated plasma cutting machine, square tube plasma cutting machine, portable plasma cutting machine, round tube plasma cutting machine, gantry plasma cutting machine.
CNC plasma cutter machine, also known as CNC plasma cutting machine, plasma cutter, plasma cutting table, plasma cutting machine.
What is the working principle of the CNC plasma cutter?
CNC plasma cutter machine, also known as plasma arc cutting machine, combined with an easy-to-operate numerical control system, uses high-temperature high-speed gas jets at the nozzle to ionize, thereby forming electrical conductors. When current passes, the conductive gas forms a high-temperature plasma arc, The heat of the arc locally melts (and evaporates) the metal at the incision of the workpiece, and uses the power of the high-speed plasma flow to remove the molten metal to form a processing method of the incision.
The basic principle is that the arc formed between the electrode and the workpiece is limited by the fine-hole copper nozzle. This increases the temperature and velocity of the plasma emitted from the nozzle. The temperature of the plasma exceeds 20,000 °C, and the velocity can be close to the speed of sound. When used During cutting, the plasma flow increases, so that the penetrating plasma jet cuts through the material, and the molten material is removed in the outflowing plasma.
The difference between this process and the oxy-fuel process is that the plasma process operates by using an electric arc to melt the metal, while in the oxy-fuel process, oxygen oxidizes the metal, and the heat generated by the exothermic reaction melts the metal. Therefore, unlike the oxy-fuel process, the plasma process can be able to cut metals which form refractory oxides, such as aluminum, stainless steel, cast iron, and other non-ferrous metals.
What are the advantages and disadvantages of plasma cutting?
The operation of one or more burners depends on the series; cutting all conductive materials; cutting medium and large thickness high-alloy steel and aluminum materials; excellent performance in small and medium-sized mild steel thickness; high-strength structural steel that reduces heat input Cutting; high cutting speed (ten times higher than oxyfuel); any processing of high-quality blanks for medium and thick plate metals; plasma cutting ensures automation; underwater plasma cutting can achieve extremely low heat radiation and low heat radiation in the workplace noise.
Limit the maximum use of 160 mm (180 mm) for dry cutting and 120 mm for underwater cutting; wider cuts; relatively high power consumption; lasers provide higher cutting quality; more expensive than oxyacetylene cutting systems; dry cutting may produce noise.
How to choose the right CNC plasma cutter machine?
“Duty cycle” is used to measure the time that the CNC plasma cutting machine can run without cooling. Expressed as a percentage, a 50% duty cycle means that the machine can run for 5-10 minutes at the specified amperage.
It measures the intensity of the current passing through your CNC plasma cutting machine. It is inversely proportional to the duty cycle, which means the lower the amperage, the better the duty cycle.
- Material type
What material do you need to cut? CNC plasma cutting machines have different versatility, and they must cut different materials efficiently.
Measured in inches per minute (rpm), this factor is simple. Just write down the rpm of the machine you are considering and compare it to the current speed you need to cut and want to cut.
- Cutting ability
What size material do you need to cut? If you need to make changes in the future, you can get a CNC plasma table with expansion space.
Do you need to transport the CNC plasma cutting machine often? If so, please understand the weight and understand how to move it.
Make sure to allocate funds for machines, transportation, installation, operation, and maintenance. Spending more money on CNC plasma machines in advance usually means lower operating and maintenance costs in the future. It also means fewer production interruptions and higher efficiency.
There are five main consumables for the CNC plasma machine: swirl ring, electrode, nozzle, fixed cover, and protective cover. Make sure that the machine consumables you buy last.
If there is no quality warranty, what will a CNC plasma machine tool be? Make sure you are protected for at least one year.
- Technical support
I hope that the CNC plasma machine you bought has no operational problems. But just in case, please make sure that you have reliable technical support to help you in a pinch.
CNC plasma cutter machine maintenance manual?
- Regularly replace consumables
Regular oil changes are essential to avoid the replacement costs associated with purchasing a new system. Similarly, regular replacement of consumables is cost-effective compared to replacing the entire torch. Continuous use of finished products and outdated consumables can affect plasma components The normal arc, which leads to the final torch failure.
What are the common signs of expired consumables? Poor cut quality is an obvious sign of part wear. Experts recommend a daily visual inspection. When nozzle oxide residues appear and there are gouging marks inside and outside the nozzle, they should be replaced.
Check the pitting of the electrode components to check whether the electrode is overused. The user guide helps to check whether replacing the electrode is ideal. If oxygen is used, the pitting depth should not exceed 3332 inches. Nitrogen and argon should be higher than 118 inches. With Gas swirls that are signs of vortexes, cracks, burns, and dust particles should be replaced in time.
- Use the right components for each job
The choice of consumables depends on the plasma gas and cutting current used for each job. The operator’s manual can help you define different types of consumables suitable for various cutting methods. Not using the specified wearing parts will shorten the life and quality of the components.
Every part in the system must operate at the correct amperage, and the nozzle is set to 95%. A low amperage level will cause embarrassing cutting, while an excessively high amperage will shorten the life of the nozzle.
- Set the flashlight correctly
The torch should last a long time by following the recommended care methods. The correct setting of all components is essential to ensure that all parts are easily aligned. Proper alignment ensures the best electrical contact. In addition, following the correct setup procedure allows for gas and cooling the effective flow of the agent.
Proper cleaning is advocated, and the torch line should be kept clean. The seat frame should be free of pollution. If you want to change the cycle, please make sure to store the consumables in a clean place to prevent dust and dirt contamination.
- Check if the gas and coolant flow is correct
It is strongly recommended to check the pressure of the gas and coolant every day. Insufficient flow can lead to improper cooling of the consumables. This will greatly affect the parts involved. Smooth and programmable air pressure is essential to maintain the cutting arc. The hard start is related to excessive air pressure Related common problems, the cutting torch cannot work when all other conditions are normal.
Cleanliness is very important, and the plasma gas must always be kept dry and clean. Gas contamination will cause early damage to the torch and shorten the life of wearing parts. The compression system is most likely to be affected by contaminated air.
- Avoid continuous use of o-ring lubricants and anti-splash compounds
Use only the required amount of o-ring lubricant to illuminate the o-ring. If you are using an anti-splash compound, make sure to completely remove the shielding layer.
Ideally, too many things can cause harm, which is the case with these two products. Avoid grease and other non-recommended lubricants. The torch does not require lubrication to function.
Similarly, lubricants are good electrical conductors and can damage the torch. Excessive use of both compounds will block the swirl ring and attract excess metal dust. All these abnormalities can cause various arc discharge problems.
- The torch cannot be used as a hammer
Never use a torch in place of a hammer. Do not use a torch to hit any unnecessary parts. Each mechanical device should be used for the specific purpose created for it.
- Don’t arc
Extending the arc beyond the set limit will cause premature damage to the torch. Always make sure to use the edge starting point instead of the perforation starting point. Whenever edge treatment is performed, the nozzle hole of the plasma arc should be directed toward the edge of the working material.
The puncture should be maintained by setting the support to twice the cutting height. You can also set it to the maximum height that allows arc transfer. Correctly setting the time of the arc extinguishing signal can prevent large stretches at the end of the cutting.
- Take precautions to prevent torch collision
A common crash in the workplace may damage the quality of the cutting torch. To prevent the torch from colliding with the working material, the cutting system should be programmed to move around the material during cutting. The collision can be mitigated by correcting the changing torch height sensor In the event of a collision, the detachable device installed on the torch can prevent any damage from occurring.
- Maintain the right confrontation
The gap depends on the thickness of the working material. Maintaining the correct support helps the arc to flow easily. The support level is too high or too low will damage the material and the torch.
Some cutters are precisely made to be handheld. Here, the operator uses a stand device to ensure efficiency. For mechanical systems, you can maintain them manually or automatically through height controls.
- Thorough and regular cleaning
Cleaning is essential for effective and efficient system operation. While ensuring that the internal and external threads of the torch are clean, check for signs of contamination in the torch. Re-tighten these components to provide additional protection. Remember to always clean the nozzle and electrode holder In order to clean the torch perfectly, please use a cotton swab or hydrogen peroxide.
With proper operation and maintenance, plasma arc systems can help reduce costs and working hours. In addition, the correct operation will result in system durability and high cutting quality. Regular maintenance will reduce the time it takes to clean the metal before it can continue the manufacturing process.
How to use plasma cutting machine?
- Before use and when cutting
- Check and confirm that the power supply, air source, and water source have no leakage, air leakage, or water leakage, and the grounding or zero connection is safe and reliable.
2. The trolley and workpiece should be placed in an appropriate position, and the workpiece should be connected to the positive electrode of the cutting circuit, and there should be a slag pit under the cutting working surface.
3. The nozzle aperture should be selected according to the material, type, and thickness of the workpiece, and the cutting power, gas flow, and electrode shrinkage should be adjusted.
- The automatic cutting trolley should be run empty and the cutting speed should be selected.
- Operators must wear protective masks, welding gloves, hats, filter dust masks, and soundproof earmuffs. Personnel who do not wear protective glasses are strictly prohibited from directly observing the plasma arc, and bare skin is strictly prohibited from approaching the plasma arc.
- When cutting, the operator should stand upwind to operate. The air can be drawn from the lower part of the workbench, and the open area on the workbench should be reduced.
7. When cutting, when the no-load voltage is too high, check the electrical grounding, zero connection, and the insulation of the torch handle. The workbench should be insulated from the ground, or a no-load circuit breaker should be installed in the electrical control system.
8. The high-frequency generator should be equipped with a shielding cover, and the high-frequency circuit should be cut off immediately after the high-frequency arc is used.
9. The use of thorium and tungsten electrodes should meet the requirements of Article 12.7.8 of jgj33-2001.
- Cutting operation and protection of cooperating personnel
1. The plasma cutting machine used on site should be equipped with rain, moisture, and sun sheds, and should be equipped with corresponding fire fighting equipment.
2. When cutting at high altitude, safety belts must be worn, fire prevention measures should be taken around and below the cutting, and a special person should be supervised.
- When it is necessary to cut pressurized containers, sealed containers, oil drums, pipes, and workpieces stained with flammable gases and solutions, first eliminate the pressure in the containers and pipes, eliminate flammable gases and solutions, and then flush toxic, harmful and flammable Substances; for containers with residual grease, they should be rinsed with steam and alkaline water first, and the lid should be opened to confirm that the container is cleaned, and then filled with water before cutting. Welding in the container should be taken to prevent electric shock and poisoning. And suffocation measures. Air holes should be left in the sealed container, and equipment ventilation equipment should be installed at the inlet and outlet when necessary; the lighting voltage in the container should not exceed 12v, and the welder and the workpiece should be insulated; the special person should be placed outside the container. It is strictly prohibited. Cut inside a container that has been sprayed with paint and plastic.
- It is strictly forbidden to cut pressure vessels and pipelines, live equipment, load-bearing structures, and containers containing flammable and explosive materials under pressure.
- Welding and cutting are not allowed in the open air on rainy days. When working in a humid area, the operator should stand in a place with insulating materials and wear insulating shoes.
6. After the operation, the power should be cut off, and the air and water sources should be turned off.