Atmospheric plasma jets or vacuum chambers bombard the surface with ions and radicals, burning off organic contamination and grafting oxygen-containing groups onto plastics. Surface energy often jumps from around 30 to above 50 dynes per centimeter in a second or two. The effect fades over hours to weeks as the polymer surface relaxes, so treated parts are bonded on a set schedule.
Plasma treatment's only good for a few days on these PP parts, bond them this week or rerun them.
Treated plastic parts lose their activation faster in warm storage and when slip additives migrate to the surface; bond them on a fixed schedule.
Also heard as
- plasma
- atmospheric plasma
Related terms
Corona treatment
High-voltage electrical discharge across a film or sheet to raise its surface energy for bonding or printing.
Surface energy
A measure of how strongly a solid surface attracts liquids, which decides whether an adhesive can wet it.
Dyne pen
A marker filled with test fluid of known surface tension, used to check a surface's treatment level.
LSE
Low surface energy, describing plastics and coatings that most adhesives cannot wet or bond without help.