Flame Cutting – (Oxy Fuel)
Oxy fuel cutting is a process which has been around for over 100 years. However, it’s still widely utilised today, and it’s still a very important aspect and technology of many industries.
Oxy fuel cutting use a combination of fuel gases and oxygen to cut metals. A variety of different fuels may be utilised, although the most common is acetylene. Other gases utilised include natural gas, propane, hydrogen, propylene, liquefied petroleum gas (LPG), and combinations of these gases. Oxy-fuel cutting begins by using a torch to heat a metal to its kindling temperature.
This is the lowest temperature at which the metal in question will spontaneously ignite. At this point, a stream of oxygen is trained onto the metal, in turn burning it into a metal oxide. This new metal oxide then flows out and away from the intact material being utilised. Any leftover slag can be wiped or tapped away. It’s actually the heat produced by the metal oxide and its contact with the rest of the material which actively continues the cutting process. The torch itself only heats the metal to begin the process.
Plasma cutting grew out of plasma welding in the 1960s, and emerged as a very productive way to cut sheet metal and plate in the 1980s. It had the advantages over traditional "metal against metal" cutting of producing no metal chips, giving accurate cuts, and producing a cleaner edge than oxy-fuel cutting. Early plasma cutters were large, somewhat slow and expensive and, therefore, tended to be dedicated to repeating cutting patterns in a "mass production" mode.
As with other machine tools, CNC (computer numerical control) technology was applied to plasma cutting machines in the late 1980s into the 1990s, giving plasma cutting machines greater flexibility to cut diverse shapes "on demand" based on a set of instructions that were programmed into the machine's numerical control. These CNC plasma-cutting machines were, however, generally limited to cutting patterns and parts in flat sheets of steel, using only two axes of motion (referred to as X Y cutting).
With CNC plasma cutting machines, a plasma torch blows an inert gas at high speeds out of a nozzle, through an electrical arc, which turns some of that gas to plasma.
Automated plasma arc cutting systems provide several advantages over other cutting methods such as oxyfuel and laser:
Rapid Cutting Speeds: plasma arc cutting is faster than oxyfuel for cutting steel up to 25 mm thick and is competitive for greater thickness. Plasma cutting achieves speeds greater than those of laser cutting systems for thickness over 3 mm. The fast cutting speeds result in increased production.
Wide Range of Materials and Thickness: Plasma cutting systems can yield quality cuts on both ferrous and nonferrous metals. Thickness from gauge to 80 mm can be cut effectively.
Economical: Plasma cutting is more economical than oxyfuel for thickness under 25 mm, and comparable up to about 50 mm.
Lumsden grinding is the removal of material by a grinding process using a ‘plough’ grinding machine. Lumsden is the name of a make of machine and it has become synonymous with the process.
The advantage of this method of machining over other methods is much higher rates of material removal compared to ‘surface grinding’. Generally, larger areas can be machined without leaving ‘witness’ lines than with conventional machining (milling).
For more information about our CNC flame cutting, CNC profile cutting or Lumsden grinding services, contact Patrick Steel Ltd today on: 02476 645 422 /