What is Plasma ?
“PLASMA“ is a gas, which contains a big amount of electrical charges. In constast to normal gases,it is conductive although it appears electrically neutral to the outside. 
Ionisation of gas molecules for (nobel gases electrons from the molecules and atoms. Besides electrons, ions and normal neutral molecule fragments (radicals),which are chemically high reactive due to their unstable structure. This reactivity is used in many technical pretreatment before printing and gluing by oxidation of the surface of the ambient conditions using air as working excitation are used for this application