Topic:

Glossary: T

Here you are going to find explications of important terms in plasma technology:

I,J

P,Q

X,Y,Z

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tarnishing a Teflon surface: see „etching Teflon"
Teflon + hydrophilic: see „etching Teflon"
Tesla: Serbian physicist; has brought AC to technical implementation; in his honour, the magnetic flux density, symbol T (corresponding to 1 Wb/m²), was named after him.
test ink: Test inks have proven of value in connection with pre-treatment methods. Treatment results can easily be determined with test inks. The method can be used as a measuring tool for the estimation of the surface energy only, if the interactions of the solvents are known and if the surface itself is not too absorptive or, examined microscopically,
test inks: The wettability or surface energy of a solid body is given in mN/m (ancient measuring unit: dyne/cm) and represents an indication for the adhesion of adhesives and coatings. For its determination, test inks following e.g. ISO 8296 are used. Since those are toxic, though, various alternatives are applied. These test inks consist of liquids with different surface tensions. If the applied test ink wets the surface completely, then the surface energy of the tested body is higher than the surface energy of the test ink; however, if the test ink rolls off or contracts, then the surface energy is lower than the test ink’s value.
test inks for the measurement of surface tension: In order to obtain optimum wetting of a surface by a liquid (printing ink, glue), the surface tension of the substratum must be considered as an important parameter. The surface tension can be seen as a relative measure for the evaluation of the ink acceptance and the estimated adhesion of an ink, an adhesive layer, or another coating to the substratum.
Plastics have a low surface tension between < 28 mN/m and 40 mN/m. But empirically only surface tensions ≥38 - 42 mN/m allow good adhesion conditions. Through an optimal pre-treatment, e.g. by atmospheric pressure plasma at Plasmatreat, a significant increase in surface tension can be obtained. That way, peak values of 72 mN/m (water wetting the smooth surface completely) are.
Estimate of the measuring results obtained through Plasmatreat® test inks
Like every measuring method, the determination of surface tension via test inks demands for critical inspection of the measuring results! The adhesive strength is influenced not only by the surface tension!
The measured surface tension must always be seen as no more than a measure for the momentary state of the substrate. Empirically, the surface tension lessens with the storage time.
Within functioning processes and under the condition that adhesive or ink and surface conditions harmonize, the measurement of surface tension via Plasmatreat® test inks represents an excellent tool for the quality assurance in the production. The maximally possible error of measurement is 2 mN/m. In multiple measurement test series, the error tolerance is reduced accordingly.
The measured values are relative values; the possibility of comparison with other measurement methods is limited!
Application of Plasmatreat test inks
Using the paintbrush that is integrated in the cap of the ink bottle, the test ink should be spread smoothly onto the surface. It is useful to start with a high surface tension after the pre-treatment. If the edges of the brush marks stay stable for two seconds (good wetting of the surface), then the surface tension of the substrate equals at least the test ink's value. If the brush marks contract, it is to be continued with the next lower test ink. By application of the different test inks, it is now possible to approach step by step the value of the surface tension of the material to be tested. The surface tension of the test ink that barely wets the surface corresponds to the surface tension to be determined. The test ink with next higher surface tension will no more be able to wet.
tetrafluormethane: Often applied process gas in plasma processes, particularly in etching processes. Under normal conditions, tetrafluormethane (CF4, also called Freon 14) is completely inert, but in plasma, it generates free fluorine atoms, and CF2 and CF3 radicals. Those cause a very strong etching effect, e.g. on silicon dioxide. Mixtures of CF4 and O2 etch approximately 5 times faster than pure oxygen.
textile treatment: Textiles and yarns consist mostly of technical synthetics nowadays. These soak up liquids because of the fine fibres’ capillary attraction, but in many cases, adhesives or coatings stick as poorly as on a compact plastic surface. Here as well, a pre-treatment is necessary. Examples are the lamination of tissues of the coating of yarns.
TOF-SIMS: Abbreviation for Time of Flight Secondary Ion Mass Spectrometry, a surface analysis method in which the surface gets bombed with a pulsed ion beam. Via the time of flight of the emitted secondary ions, their mass and therewith the element can be distinguished.
tribology: see "friction"