What is surface treatment?

Answer 1

Until the 1950's, matter was thought to exist in only three forms i.e. solid, liquid, and gas. But all that changed when a Danish engineer discovered plasma. As it is known, plasma is matter that exists in the form of ions and electrons. Basically, it is a gas that's been electrified charged with freely moving electrons in both the negative and positive state. The situation is actually a resultant of further energy being given to a gas which causes the breaking free of negatively charged electrons from the nucleus.

On a deeper level, plasma can be described as a gas that's been partially ionized. It is a mixture of neutral atoms, atomic ions, electrons, molecular ions, and molecules present in excited and ground states. The charges (positive and negative) balance each other therefore; a good number of these charges are electrically neutral. The charged particles present in plasma are responsible for its high electrical conductivity.

Since plasma consists of electrons, molecules or neutral gas atoms, positive ions, UV light along with excited gas molecules and atoms, it carries a good amount of internal energy. And when all these molecules, ions and atoms come together and interact with a particular surface, plasma treatment is initiated. Hence, by selecting a gas mixture, pressure, power etc. the effects of plasma treatment upon any surface can also be specified or precisely tuned.

A plasma treatment is usually performed in a chamber or enclosure that's evacuated. The air within the chamber or enclosure is pumped out prior to letting gas in. The gas then flows in the enclosure at a low pressure. This is done before any energy (electrical power) is applied. It is imperative to know that plasma treatment performed at low temperature can easily process materials that are heat sensitive. These types of plasma are sometimes referred to as 'cold plasma'.

Plasma treatment is mainly used for cleaning, surface activation, deposition, and etching etc. On an industrial level, plasma treatments are used for treating surfaces of various materials prior to any coating, printing or adhesion. Therefore, it can also be referred to as a kind of pretreatment of surfaces. Treatment with plasma removes any foreign contaminants present on the surface of a material making it more suitable for further processing.