What is the application of corona discharge?
Corona discharge has been applied to treat the surface of plastics to render them adherable. In this method, the plastic article is exposed to a corona discharge produced by high-frequency, high-voltage alternating current.
What is corona discharge explain?
Corona discharge is an electrical discharge brought on by the ionization of a fluid surrounding a conductor, which occurs when the strength of the electric field exceeds a certain value.
What is corona discharge or action of points?
The positive ions are repelled at the sharp edge and negative ions are attracted towards the sharper edge. This reduces the total charge of the conductor near the sharp edge. This is called action at points or corona discharge.
What is the function of corona discharge in extrusion process?
Corona treating increases the surface energy of plastic films, foils, paper and polymer objects to improve wettability and adhesion of inks, coatings and adhesives. Treating works best when a substrate is treated at the time of extrusion and in-line prior to converting.
What are the advantages of corona effect?
The main advantages of corona effects are: Due to corona across the conductor, the sheath of air surrounding the conductor becomes conductive which rises the conductor diameter virtually. This virtual increase in the conductor diameter reduces the maximum potential gradient or maximum electrostatic stress.
What is corona discharge for class 12th in physics?
Conductors with pointed ends have very high electric field near these ends which may cause dielectric breakdown in air. The charge may jump from the conductor to the air because of increased conductivity of the air, accompanied by a visible glow near the pointed ends. This phenomena is corona discharge.
Which of the following statement is true corona loss increases with?
Where, f = Supply frequency δ = Air density factor r = Radius of the conductor d = Distance between the conductors Vph = Operating voltage of the transmission line Vc = Critical disruptive voltage Therefore, Corona loss ∝ supply frequency and Corona loss ∝ (Vph – Vc)² Vc ∝ r Therefore, corona loss increases with the …
How is corona treatment measured?
There are no limits to the substrates that can be Corona treated, but the intensity of the treatment required will vary significantly according to their chemical make-up. The best way to determine the exact value is by testing a sample of the actual film that is being used for a specific application.
What is corona treatment in packaging?
A corona treating system is designed to increase the surface energy of plastic films, foils and paper in order to allow improved wettability and adhesion of inks, coatings and adhesives. As a result, the materials treated will demonstrate improved printing and coating quality, and stronger lamination strength.
What are the advantages and disadvantages of corona discharge?
(ii) Corona reduces the effects of transients produced by surges. (i) Corona is accompanied by a loss of energy. This affects the transmission efficiency of the line. (ii) Ozone is produced by corona and may cause corrosion of the conductor due to chemical action.