Fluorination
Surface finishing
The demands on the characteristics of commodities’ surface structure become higher and higher. Beside an attractive and touch-appealing design with the help of lacquering, environmental aspects are also top priority. Polymers – which are ideal with respect to processing and creation possibilities – often encounter their limits due to poor adhesion and negative wetting properties. These deficits can be eliminated economically and permanently with the help of fluorination. With only one working step, without mechanical load, the surface tension is altered. Hydrogen atoms of the molecular chains are substituted with oxygen atoms and one obtains new characteristics:
- Increase of adhesiveness of lacquers
- Decrease of permeation of gases and fluids
- Improved gliding / reaming properties of plastics
Compared to other pretreatments of surface structures (as flame impingement, Corona or low pressure plasma), fluorination causes permanent and smooth surface characteristics (regardless of the component geometry).
OPERATING PRINCIPLE OF THE FLUORINATION
Before the fluorination
Plastics show excellent qualities as easy processing, low weight and high chemical resistance. Fluorination offers an effective opportunity to expand the range of application possibilities.
The strong responsiveness of the fluorine gas causes the substitution of hydrogen atoms by fluorine atoms on the surface of the component. The altered surface layer shows a high binding energy and is thus very resistant.
After the fluorination
After the fluorination, the surface layer is permanently modified, has excellent adhesive characteristics, shows a strikingly lower permeation towards other substances and has a better floating and reaming performance.
Excellent adhesion
With the fluorination, the wettability of the plastics increases. The wettability is an important requirement for a sufficient adhesion of lacquers and adhesives. The higher the surface tension, and so the wettability of the surface to be finished, the better these surfaces can be lacquered. This relatively high penetration of the fluorine is additionally causing the stable and long-lasting effect of the fluorination. Therefore, the pretreatment is maintained even with moving molecules, caused for example by temperature change. Compared to the common pretreatment methods, this thick and modified surface of multiple molecule layers shows significant advantages especially with all objects which are subject to increased exposure before the treatment.
The permeation of liquids (here toluene) and gases with polymer components can often be reduced by orders of magnitude with fluorination.
Reduced permeation
With the possibility to lower the gas and liquid permeability of plastic components with the help of fluorination, economic and ecological aspects can be combined. On the one hand, a loss of volume and change of properties of the products can be avoided, and an environmental impact by fumes and odors can be reduced. On the other hand, cost-efficient, light and economically- as well as resource-friendly packing can be used.
The improved surface properties by means of fluorination, give more security for the processing of the components to be redefined. For the lacquering no primer is needed since the fluorinated surface offers a perfect adhesion basis. The achievable improvement of the surface energy depends primarily on the duration of the fluorination, the temperature and the amount of fluorine gas used. The adjustment of these parameters is a decisive aspect of Maincor’s competence. Consulting service is for Maincor a question of qualification since behind every product sold lies a huge responsibility.
ADVANTAGES OF THE PROCESS
The offline fluorination is a testified method of plastic surface treatment. In comparison to other treatments as flame impingement, Corona and plasma, the fluorination offers significant advantages:
RESEARCH AND DEVELOPMENT
- Pre-treatment of plastic parts for the subsequent leather lining
- Liquid container with decreased permeation (permeability of gases)
- Pre-treatment of plastic parts for the subsequent, long-lasting adhesion of other components
- Improved gliding / reaming properties of plastics
- Increase of adhesiveness of lacquers
Jürgen Schmich
Tel.: +49 (0) 9527 95 16 144
Fax: +49 (0) 9527 95 16 244
juergen.schmich@maincor.de
Further information
The effect of fluorination for new parts is tested in long term tests. The result of these studies give customer the safety of acquiring a reliable service for his products.
