Plasma Cutting Process
The formation of a constricted plasma arc created with the assistance of ionized gases and electricity melts a metal substrate during plasma cutting. The process depends upon pressurized gases (such as argon or nitrogen) flowing past an electrode through a nozzle to create a plasma arc with a metal work surface. The arc slices through the substrate, causing it to melt rapidly.
The “plasma” consists of material ionized during the fabrication process. Plasma arc cutting enables machinists to penetrate hard metals such as stainless steel and aluminum with ease. Manufacturers sometimes increase the temperature within the plasma arc by shielding it with an outer flow of inert gases.
Hand Held vs Mechanized Plasma Cutting
Less expensive conventional hand held plasma cutting tools do not offer the precision of computer-controlled CNC plasma cutter equipment. While these products do supply highly cost-effective assistance in many machine shop and scrapyard settings, they cannot ensure the uniformity of computerized production processes for large-scale metal fabrication. Manufacturers who anticipate engaging in a high volume of production sometimes invest in more expensive CNC plasma cutter tools.
CNC Plasma Cutters
Widely used CNC plasma cutters vary considerably, depending upon the requirement of individual manufacturers. However, these tools usually share three aspects in common:
Process of CNC Plasma Cutting
Every CNC plasma cutting tool ultimately relies upon a computerized control unit to automate the process of plasma cutting. Many modern machines permit operators to store useful programs for convenient access.
A CNC plasma cutting device may include a variety of specialized parts and accessories. However, these units will typically incorporate some of the same mechanical parts: a computerized controller unit of some type, a work table or other fixture, a power source, a drive system with applicable motors, a source of compressed gas, an arc starting console, an electrical system to address inputs and outputs, and a mechanized plasma torch assembly.
The computer relies upon a software program containing coordinates to guide the movements of automated components in the system. For example, the computer may direct a cutting head to turn at designated angles to cut a workpiece into a desired shape. Manufacturers have developed CNC plasma cutting machines with sophisticated proprietary computerized controllers which include user-friendly interface consoles.
The computerized tools employed in industrial environments today can effectively cut a wide variety of metal parts. These CNC plasma cutters typically rely upon three important configurations:
Tube And Section Plasma Cutting
Typically, in this CNC plasma cutting configuration, the operator will turn or rotate a tube-shaped or extruded metal part in front of a completely immobile plasma cutting head. This system may also work well for workpieces moving along a timed conveyor belt, for instance.
Two Dimensional / 2-Axis Plasma Cutting
Manufacturers can cut sheets of metal effectively utilizing this configuration. It places the cutting head at right angle to the workpiece. In some cases, the cutting head moves at a uniform height across a two-dimensional X-Y axis.
Three dimensional / 3+ Axis Plasma Cutting
This configuration allows a fabricator to cut metal in a variety of different angles by adjusting the cutting head. For instance, a manufacturer may reduce costs associated with some other machining operations, such as grinding, by implementing 3-D plasma cutting configurations. This capability sometimes provides a useful way to prepare a metal edge for welding, for example.
Numerous applications exist in today’s diverse fabrication environments for both manual plasma cutting tools and CNC-controlled plasma cutting industrial machinery. Originally used in aircraft manufacturing plants and shipyards during the Second World War, this specialized welding technique for cutting certain metals permits both large scale manufacturers and hobbyists to generate a variety of useful shapes quickly. For instance, metal artists frequently employ plasma welding to create decorate cutouts. These tools will cut metals such as steel, aluminum, brass, and iron alloys.
Today, widespread plasma cutting occurs in the automotive industry, metals fabrication shops, industrial construction plants, and salvage and scrapyard operations. Specialized CNC plasma cutter tools have found extensive use within the HVAC industry during duct manufacturing, for instance. This machine process also assists in the creation of decorative metal fencing and gates, metal signs, metal trellises and garden artwork.
Plasma cutting offers a very significant speed advantage. Although laser cutting today often permits greater cutting precision, plasma cutting has grown more accurate in recent years. It can enable manufacturers to perform cutting operations very rapidly on appropriate metals and metal alloys. The type of substrate and the thickness of the workpiece both influence the utility of some automated plasma cutting tools within a fabrication environment.
This machine process also proves extremely useful in preparing the surfaces of some metal parts for subsequent welding operations. A manufacturer may enjoy cost advantages in certain sitations by employing plasma cutting tools.
Today, automated plasma cutting sometimes offers safety advantages, too. As with laser cutting, personnel must wear protective eye gear to safeguard their vision. However, manufacturers who maintain safety-conscious fabrication environments potentially obtain benefits by using automated plasma cutting technology instead of manual cutting tools.
Finally, plasma cutting offers an effective, efficient cutting technology for use with metals such as aluminum and stainless steel. The price of some plasma cutting tools has fallen in recent years, making these products more widely available.