An overview of plasma flame surface activation technique
Plasma flame treatment is one of the most reliable surface activation techniques used in a number of industries for modifying the surface tension of metals and plastic. The technique is based on the production of plasma by combusting a hydrocarbon fuel at a very high temperature. The fuel is chosen in accordance with the physical and chemical properties of the surface being treated. Plasma consists of high energy ionized particles. When a material is placed in a plasma medium, plasma particles transfer their energy to the surface molecule of the material and increase the surface tension of the material thus making it suitable for adhesion and painting.
A plasma flame treatment system consists of the following modules:
- Fuel Injector- it is a stainless steel nozzle and serves the purpose of providing fuel for plasma. Hydrocarbon fuel is injected in the nozzle where it is combusted in the presence of oxygen or air.
- Burner- the fuel is heated at a very high temperature (1816°C). The burner is constantly monitored because variations in temperature can alter the reactive properties of plasma.
- Plasma exit- plasma from the fuel injector comes out through a small outlet. Other gases formed during the combustion escape through a small outlet.
Precise control of the following parameters is critical to the success of flame treatment technique using plasma:
- Flame temperature should not exceed the standard limit set for plasma production.
- The material being treated should be placed at a moderate distance from the burner.
- The type of fuel varies with the physical and chemical properties of the material being treated.
- Pressure of the plasma plant should be controlled as it influences the mobility of plasma particles.
Exposure time is another factor which should be monitored closely. Too much exposure can burn the material surface.
Following are some of the industrial applications of flame treatment using plasma:
- The technique is heavily used by automobile manufacturers to improve the surface tension of vehicle parts.
- It is also used as a cleaning agent, as plasma has the ability to remove organic residues from the surface of a material without changing its properties.
- The technique is also used in aircraft industry to improve the bonding between various metal and plastic parts.
- Mechanical reciprocators and robot manufacturers are also relying on plasma surface treatment for modifying the physical properties of metals
- Plasma treatment is also used to reduce the risk of metal corrosion.
- Following are some of the many benefits of flame treatment using plasma over other surface activation techniques:
- This technique utilizes modern instruments which have reduced the risk of human errors.
- Plasma surface treatment is safer than gas treatment.
- The by-products formed in plasma treatment are mostly volatile.
- The technique is not only more reliable than traditional methods of surface activation, but also environment friendly.
Plasma treatment for surface activation has become one of the most frequently used surface activation techniques on commercial scale. By keeping in consideration the above mentioned parameters, high quality results can be achieved.