Selection, operation and maintenance of Plasma Cutting Equipment

Plasma Cutting Equipment  is a kind of processing method using the heat of high temperature plasma arc to make the metal part or part of the workpiece incision melt, and by the momentum of high speed plasma to eliminate the molten metal to form the incision.

How to choose plasma cutting machine

Two, the use of plasma cutting machine advantages

Three, the operation of plasma cutting machine should pay attention to the safety guarantee

Four, plasma cutting machine daily maintenance and maintenance

First, how to choose CNC plasma cutting machine

Price of 1.

No matter what kind of plasma to purchase, it is very important to consider the budget, because if you ignore the budget, even if the desired effect can be achieved, if the budget is too much beyond the budget, you may not buy it.At present, the plasma is mainly divided into domestic and imported two categories, among which the domestic price is divided into low, medium and high three specifications, but the overall user should be acceptable!And the price of import is relative to homegrown for, want to rise above several times, reach tens of times, and resemble a kind of consumable of cutting mouth and electrode also is expensive much!Normally, the imported plasma is relative to the same specifications of domestic plasma, the cutting effect is better, its disadvantage is that the price and the late use of the cost is too high, the general enterprise is difficult to accept!

2. Cutting thickness

No matter what kind of plasma, it has its own most suitable cutting size range, usually small power plasma is suitable for cutting thin plates, it is well known that the plasma power is too large, but not for cutting thin plates!At present, the domestic steel plate below 2mm, the use of domestic 40-60A plasma cutting more, occasionally also use imported, but the number is not much, because the price is more expensive.In this serious statement, less than 2MM below the steel plate, remember in addition to the use of high-speed desktop sheet special plasma cutting machine, any other models: such as portable, gantry type are not suitable for cutting.More than 2mm is not subject to this restriction and can be used.And thick steel plate such as 2-16mm steel plate, portable and gantry type models can be cut, and then thick, such as 25mm plate or even thicker, only gantry type models is the right choice!

3. Cut the material

This general engaged in metal processing technicians know that plasma is used to cut stainless steel and other alloy materials is its strength, carbon steel plate is mainly rely on the flame cutting way to work, so as long as there is stainless steel, it must be matched with plasma cutting machine!Otherwise, the flame can not be processed!

Plasma cut stainless steel material

Two, numerical control plasma cutting machine use advantages

1. Better cutting quality

Slag hanging, heat affected zone, top edge fillet and cutting Angle are the main factors affecting cutting quality.Especially in the two aspects of slag and heat affected zone, plasma cutting is far better than flame cutting, the edge of the plasma cutting basically does not remain slag, and the heat affected zone is much smaller.

2. Hang slag

Plasma processes use high-temperature, electrically charged gas to melt metal and blow the molten material off the cutting surface.The flame cutting is the use of oxygen and steel produced between the chemical reaction for cutting, resulting in red iron slag or slag hanging.Because of the difference in this process, plasma cutting produces less hanging slag, and the attached hanging slag is easier to remove.These slags can often be knocked off easily without grinding or removing, greatly reducing the time required for secondary processing.Fewer grinding operations result in higher productivity.

3. Heat affected zone

One concern when cutting metal is the size of the heat-affected zone created.High temperatures can change the chemical structure of the metal, darkening (tempering color) and warping the heated edges. If the heated edges are not removed, the workpiece may not be suitable for secondary welding.The faster the torch moves, the smaller the heat affected zone, regardless of the process used.The rapid cutting characteristics of the plasma result in a smaller heat-affected zone, thus shortening the time spent on the secondary machining to clear the heated edge.Some flame cutting users may also be concerned about the tempering color.The heat-affected zone is not visible from the outside, but the tempering color is not, which discolors the metal.Similarly, the rapid cutting of plasma results in a smaller tempering area.

Underwater plasma cutting and cutting parts

4. Higher productivity

CNC plasma cutting machines and perforations can reach speeds up to 8.5 times faster than flame cutting, and the huge productivity gains can be huge, not to mention the time saved in preheating and reprocessing.

5. Lower cost per part

When analyzing costs, it is important to understand the difference between operating costs and operating costs per part or per meter.So how do you determine the actual cost of cutting a part?Operating cost per meter is the value of all the costs required to cut per hour divided by the total length (meters) that can be cut in one hour.The costs involved in cutting include wearing parts, electricity, gas, labor and maintenance overhead.Cost per part is the value of the total length of cutting required to produce a part multiplied by the operating cost per meter.Plasma systems can cut faster and produce more parts at any given time, so the cost per part is much lower.For hand-held cutting, calculating the cost per job or task gives a better estimate of the cost savings.The cost of running the job per hour times the total time required to complete the job equals the cost of the job.For flame cutting, be sure to count the warm-up time and long secondary processing time in the required time.

6. Higher profitability

The lower cost per part of a plasma system leads directly to higher profits.Cutting every part saves money and improves profit margins.The more parts are cut per hour, the more total profit will increase.

7. Easier to use

For users who use flame cutting, mastering the setting of flame chemical parameters and maintaining the chemistry of the flame takes time to learn and practice.Easy to cut from templates and patterns, especially those with curves.No gas adjustment, drag and cut capability, and easy-to-use controls make the plasma system easier to learn.

8. Greater flexibility

The plasma system can cut any conductive metal, including stainless steel, aluminum, copper and brass.Flame cutters, on the other hand, use a chemical reaction between oxygen and the iron in mild steels, so they can only be used to cut low steel.In addition, the plasma system can be used for planing, marking or cutting rusted, painted or even stacked metal.Also, you can use a plasma system for bevel cutting or cutting steel mesh, which is difficult to do with flame cutting.

9. Greater security

The fuel used for flame cutting is a mixture of oxygen and gas.The most commonly used fuel gases are acetylene, propane, MAPP, propylene, and natural gas.One of the most commonly used is acetylene, because acetylene produces a higher flame temperature and perforates faster than other gases.However, acetylene is an unstable and highly flammable gas that is extremely sensitive to excessive pressure, temperature and even static electricity.An acetylene explosion can cause thousands of dollars in property damage and serious injury to people nearby.Some plasma systems, such as the PowerMax series, are usually operated by compressed air and do not require the use of flammable gases.Hypertherm's HPR and XPR plasma systems can use a variety of gases (including air), the most commonly used being oxygen and nitrogen.These gases are more stable than acetylene and do not require much special treatment.All types of thermal cutting will produce some odour and noise, however, the use of cutting bed and CNC plasma cutting machine system of thermal cutting can choose water cutting bed, which can greatly reduce odour and noise.Most flame cutting should not be done underwater because of the potential for explosion.

Three, the operation of plasma cutting machine should pay attention to the safety guarantee

(1) Operators must wear protective masks, welding gloves, hats, filter membrane dust masks and sound insulation earmuffs.People who do not wear protective goggles are strictly forbidden to observe the plasma arc directly. Bare skin is strictly forbidden to approach the plasma arc.

(2) when cutting, the operator should stand in the upwind operation.The air can be pumped from the lower part of the worktable, and the open area of the operating table should be reduced.

(3) When cutting, when the no-load voltage is too high, electrical grounding, zero connection and insulation of cutting torch handle should be checked, and the workbench should be insulated from the ground, or no-load circuit breakers should be installed in the electrical control system.

(4) the high frequency generator should be equipped with a shielding cover, with high frequency arc, should immediately cut off the high frequency circuit.

(5) The use of thorium and tungsten electrodes shall comply with the provisions of Article 12.7.8 of JGJ33-2001.

(6) The cutting operator and cooperating personnel must wear labor protective equipment according to the regulations.Safety measures must be taken to prevent electric shock, falling from high altitude, gas poisoning and fire accidents.

(7) The electric welding machine used on site should be equipped with a shelter against rain, moisture and sun, and should be equipped with corresponding fire fighting equipment.

(8) When welding or cutting at high altitude, the safety belt must be fastened. Fire prevention measures should be taken around and below the welding cutting, and special person should be under supervision.

Four, plasma cutting machine daily maintenance and maintenance

1. Install the cutting torch correctly

Install the cutting torch correctly and carefully to ensure that all parts fit well and that the gas and cooling air flow.Install all parts on a clean flannelette to avoid dirt sticking to the parts.

2. Consumable parts should be replaced in time before they are completely damaged

Do not replace consumable parts after they are completely damaged, because severely worn electrodes, nozzle and vortex ring will produce uncontrollable plasma arc, which can easily cause serious damage to the cutting torch.Therefore, when the cutting quality decreases for the first time, consumables should be checked in a timely manner.

3. Clean the connecting thread of the cutting torch

In the replacement of consumable parts or daily maintenance inspection, must ensure that the internal and external threads of the cutting torch clean, if necessary, should be cleaned or repaired connecting threads.

4. Clean the contact surface between electrode and nozzle

In many cutting torches, the interface between the nozzle and the electrode is a charged interface. If there is dirt on these interfaces, the cutting torch will not work properly.

5. Check gas and cooling gas daily

Check the flow and pressure of gas and cooling airflow every day. If it is found that the flow is insufficient or there is leakage, stop immediately to troubleshoot.

6. Avoid collision damage of cutting torch

In order to avoid the collision damage of the cutting torch, it is necessary to program correctly to avoid the over-limit walking of the system and install the anti-collision device to effectively avoid the damage of the cutting torch during the collision.

7. The most common causes of cutting torch damage

① cutting torch collision.(2) Damaging plasma arc due to damage of consumable parts.(3) the destructive plasma arc caused by dirt.(4) the destructive plasma arc caused by loose parts.

8. Matters needing attention

① Do not grease the cutting torch.② Do not overuse O-ring lubricants.(3) Do not spray anti-splash chemicals when the cover is still on the cutting torch.④ Do not use the manual cutting torch as a hammer.