Plasma Cleaning

Plasma cleaning is a proven, effective, economical and environmentally safe method for critical surface preparation. Plasma cleaning with oxygen plasma eliminates natural and technical oils & grease at the nano-scale and reduces contamination up to 6 fold when compared with traditional wet cleaning methods, including solvent cleaning residues themselves. Plasma cleaning produces a pristine surface, ready for bonding or further processing, without any harmful waste material.

How Plasma Cleaning Works

Ultra-violet light generated in the plasma is very effective in the breaking most organic bonds of surface contaminants. This helps to break apart oils and grease. A second cleaning action is carried out by the energetic oxygen species created in the plasma. These species react with organic contaminants to form mainly water and carbon dioxide which are continuously removed (pumped away) from the chamber during processing.

If the part to be plasma cleaned consists of easily oxidised materials such as silver or copper, inert gases such as argon or helium are used instead. The plasma activated atoms and ions behave like a molecular sandblast and can break down organic contaminants. These contaminants are again vaporised and evacuated from the chamber during processing.

A scientific illustration of a contaminated part prior to plasma cleaningA scientific illustration of a contaminated part during plasma cleaningA scientific illustration of a contaminated part completely cleaned using plasma treatment

 

Plasma cleaning is suitable for:

  • hyper-fine cleaning of metal surfaces
  • surface preparation of plastics & elastomers
  • surface preparation and cleaning of ophthalmic and general glass products
  • ceramics
  • removing oxidation from surfaces

 


Comparison of Plasma Cleaning & Wet Chemical Cleaning

Plasma Cleaning

Wet Chemical (solvent/aqeous) Cleaning

Processes are precisely controllable through power,
pressure, gas type, processing time etc.
Processes are very sensitive to processing time
and chemical concentrations
No organic residues remain Reliability depends on satisfactory neutralisation of residues
which may require further processing steps
‘Waste’ is harmless and always in gaseous form that can be liberated directly to atmosphere High volume of liquid waste which requires expensive treatment and is subject to tight regulations
Most of the gases used have no toxicity Most of the solvents and acids used are extremely hazardous

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