Topic:
Glossary: F
Here you are going to find explications of important terms in plasma technology:
- fibre glass
- see “glass fibre”
- fibre optics
- see “glass fibre”
- flame impingement
- Flame impingement is a physical surface treatment method, in particular for plastics. Via a gas flame featuring an oxygen surplus, the surface is heated for a short time without the plastic being melted. Flame impingement is mainly used for the treatment of shapes previous to varnishing. But there are application areas for the preparation of foils previous to printing as well.
- fluorescent tube
- Low pressure gas discharge in a mixture of the rare gas argon and mercury vapour. In the positive column of this discharge, the mercury atom is excited by electron impact to emit ultraviolet radiation. A layer of luminescent material on the inner tube wall converts the UV-radiation to visible light.
- fluorination
- Processing, like e.g. the agglutination, flocking, varnishing, coating of plastics, often causes problems. Plastics have mostly non-polar surfaces. That’s why adhesives and varnishes are often incapable to generate sufficient adhesion to these surfaces. Through fluorination, polar groups are built up on the surface that improve adhesion without affecting the plastic material.
- friction
- Friction is a physical force that acts against the relative movement of two contiguous bodies. If a body is to be moved while being in contact with another one, work has to be done against the forces resulting from this contact. If a block is pulled upon by a defined force, then the block moves as soon as the force is higher than the adhesional force. If two solid bodies are moved relative to one another, then dynamic friction can be observed. In engineering, such a frictional force can be lowered by lubrication. Another possibility to decrease friction is the modification of the surfaces through deposition of atoms and molecules onto surfaces. The specific subject of friction is called tribology.
- frictional properties
- see "friction"
- functionalisation
- Functionalisation is one possibility to give a surface defined and designed chemical and physical properties. It can be done by superimposing molecules (silanes, SiOx) onto the surface, e.g. through vaporisation, deposition from a gas phase or through application of some special precursor-gas (TEOS, HMDSO, HMDSN) via plasma. For some materials, like certain plastics, it is possible to integrate atoms up to 10 nm deep into the surface by a simple plasma treatment. The kind and the concentration of the atoms can be distinguished by choice of the ionisation gas (air, O2, N2).
