Gas phase fluorination

Depending on the product, gas phase fluorination involves the use of either the inline or the offline process.

In the offline process, the formed parts are treated in a vacuum reactor to improve surface bonding, permeation or slip characteristics. The configuration and size of the reactor depends on the parts requiring pre treatment.

All parts are evenly fluorinated without the risk of undercutting or "shadowing" of two neighbour parts, even in large reactors with capacities of several cubic meters. Small parts receive optimum pre treatment when grouped together as bulk material in a rotating inner drum.

In the inline process, all forms of continuously extruded plastic profiles can be fluorinated within the production process, as can plastic films and foams.

In this application the material moves from roller to roller. It is transported to the chamber via deflecting rollers and travels over a number of rollers inside the reactor. The number of rollers is selected in line with the material type and the desired active length of time the material is to be exposed to the fluorine atmosphere.

Shortly after entering the chamber, the web is exposed to fluorine gas from one or both sides and then passes through the remaining section of the chamber where the gas mixture is circulated. The throughput of material is dependent on the design of the plant and the desired surface activation. At the end of the winder the gas mixture is removed via the calcium carbonate absorber. This process creates common fluorspar (calcium fluoride).