Procedure:

• Prior to flame treatment the surface must always be thoroughly cleaned and degreased.
• Use a propane or acetylene flame with an excess of oxygen (blue, raging flame)
• The flame is passed across the plastic surface
• Visible roughening of shiny surfaces; Formation of polar structures on the surface, so enhancing the surface tension

Points to heed:

• Clean the substrates beforehand
• Ensure there is an excess of oxygen in the flame
• Ensure the correct distance between the flame and substrate surface
• Very rapid degradation of the pretreatment effect, so bond the substrates immediately after treating them
• For thin substrates, too long contact and too small flame-substrate distances: Risk of combustion of the plastic surface