Process and device for surface pre-treatment of plastic by means of an electrical corona discharge

US4929319A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Peter Dinter · Obermoschel, DE
• Lothar Bothe · Mainz, DE
• John D. Gribbin · Schlangenbad, DE

Key dates

• Filing date: Feb 17, 1988
• Grant date: May 29, 1990
• Expiry date: Feb 17, 2008

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01T19/00
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

For surface pre-treatment of a plastic article, such as a film sheet or the interior of a plastic molded article, by means of electrical corona-discharge, a device is provided having a generator 5 and a corona discharge device 11. The generator applied a high-frequency, high-voltage alternating current to the discharge electrodes 4 of the corona-discharge device 11. The grounded counterelectrode used is the metal core 2 of a roller 10 over whose peripheral coating 3 a film sheet 1 is transported. A housing 6 encompasses the electrodes 4 of the corona-discharge device 11 and is connected via a line 7 to an atomizer 8 in which a liquid is atomized to form an aerosol by means of a piezoelectrically operating ultrasonic vibration system or by two-component atomizer nozzles which operate at ultrasonic speed. A fan 9, the throughput rate of which can be regulated, is connected to the atomizer 8 and pushes the carrier gas, for example, air, for the aerosol through the atomizer into the corona-discharge device 11. Further corona-discharge devices can be present into which an aerosol of another liquid or only a reactive gas are fed.